Dissertations / Theses on the topic 'Recycling of concrete'

This research investigates complete recycling and utilization of waste concrete to produce new structural concrete through geopolymerization. The investigation was conducted through both macro-and micro/nano-scale studies. First the geopolymer paste synthesized using a mixture of waste concrete fines (WCF) and class F fly ash (FA) as the source material and a mixture of NaOH solution (N) and Na2SiO3 solution (SS) as the alkaline activating agent was studied. Various NaOH concentrations, SS/N ratios, and WCF contents were used to produce geopolymer paste specimens in order to study their effect on the properties of the geopolymer paste. Uniaxial compression tests were conducted to measure the strength of the geopolymer paste specimens. X-ray diffraction (XRD), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), and Fourier transform infrared spectroscopy (FTIR) analyses were performed to investigate the micro/nano-structure, morphology and phase/surface elemental compositions of the geopolymer paste and the effect of calcium (Ca) on them. The results indicate that by using 10 M NaOH solution, SS/N of 2 and 50% WCF, the highest geopolymer paste strength can be obtained. Second, the interfacial transition zones (ITZs) between geopolymer (GP) and recycled aggregates (RA) were studied. Considering that RA consist of the stone particles and the attached paste/mortar from the original ordinary Portland cement (OPC) concrete, both the ITZs between GP and natural aggregate (NA) and those between GP and residual OPC paste/mortar (ROPM) were studied. For comparison, the ITZs between OPC paste and NA and those between OPC paste and ROPM were also investigated. 4-point bending tests were conducted to measure the bonding strength of the different types of ITZs at water to solid (W/S) ratio of 0.30, 0.35 and 0.40 for the geopolymer and OPC pastes after 7 and 14 days curing, respectively. SEM imaging was performed to investigate the microstructure of the ITZs. The results indicate that when NA is used, the bonding strength of both the GP-NA and OPC-NA ITZs decreases with higher water to solid (W/S) ratio. When ROPM is used, higher W/S ratio leads to smaller bonding strength for the GP-ROPM ITZ but greater bonding strength for the OPC-ROPM ITZ. Based on the measured bonding strength values for NA- and ROPM-based ITZs, the bonding strength of the GP-RA and OPC-RA ITZs was estimated by considering the average area coverage of ROPM on the RA surface. The GP-RA ITZ has the highest bonding strength among the different ITZs, implying the great potential for utilizing waste concrete (both the WCF and the RA) to produce geopolymer concrete. Third, based on the studies on geopolymer paste and ITZs, geopolymer concrete (GPC) was produced and studied using WCF and FA as the cementitious material and RA as the aggregate. For comparison, GPC using NA was also produced and studied at similar conditions. Various NaOH concentrations, SS/N ratios, and cement (WCF and FA) to aggregate (C/A) ratios were used to produce GPC specimens in order to study their effect on the behavior of GPC. The effect of water content and curing temperature on the initial setting time and 7-day unconfined compressive strength (UCS) of the GPC was also studied. The results show that the GPC produced from RA has higher UCS than the GPC from NA at both room curing temperature and 35°C curing temperature. Based on this study, it can be concluded that waste concrete can be completely recycled and used to produce new structural concrete based on the geopolymerization technology. Fourth, considering that the Si/Al and Na/Al ratios have great effect on the geopolymerization process and the properties of the final geopolymer product, a study was conducted on copper mine tailings (MT)-based geopolymer containing different amount of aluminum sludge (AS). The results indicate that by including AS and utilizing appropriate amount of NaOH, the UCS can be increased significantly. The main reason is because the addition of AS along with utilization of appropriate amount of NaOH makes both the Si/Al and Na/Al ratios reach the optimum values for geopolymerization, leading to higher degree of geopolymerization and more compact geopolymer microstructure. It is noted that although this study is not directly on waste concrete, it provides useful information for optimizing the design on complete recycling and utilization of waste concrete to produce new GPC. Finally, to better understand the effect of Ca on the geopolymerization process and the properties of geopolymer, molecular dynamics (MD) simulations were performed on geopolymer at different Ca contents. The molecular models at different Ca contents were constructed and uniaxial compression test was then performed on the numerical specimens. The results indicate that MD simulation is an effective tool for studying the effect of Ca on the properties of geopolymer at nano-scale.

Concrete, as primary building material, is widely used in most construction project. For this reason, large amounts of concrete waste were generated from construction and demolition. One way to reuse concrete waste is to use it as backfill material for landfilling and road bases. While the demand for backfill material is decreasing as the basic infrastructure construction gradually completes. Another way to reuse concrete waste is to grind it and use it as aggregate in casting new concrete. However, the reuse as aggregate for casting concrete requires large amount of cement. It is unsustainable because the production of cement causes significant amounts of carbon dioxide emission. How to deal with the concrete waste in a sustainable way is presently an urgent issue. Powder compaction is a new approach to completely recycle concrete waste in an environmentally friendly way. This new method was studied in the Sakai lab of the Institute of Industrial Science, The University of Tokyo. The process consists of crushing and milling concrete waste into a fine powder, filling the powder into moulds and compacting it under high pressure. By this process concrete waste powder can be turned into a solid concrete with mechanical properties so that it has potentials to be used again as a building material. Data from previous studies show that the compacted concrete waste can reach strength for construction but the required compaction pressure is quite high. Wood flour can be added in compaction for improving tensile strength and reducing compaction pressure. Lignin is a wood substance that melts under high temperature, fills gaps and improves bonding between particles. Cellulose from the wood substance functions as fibres which improves tensile strength. Wood waste from production of timber building materials, furniture and other wooden products also forms a larger quantities. Recycling of concrete waste with wooden waste through heating compaction is a potentially sustainable method. This Master thesis presents research on the effect from different production conditions on the bending strength of recycled concrete waste with wood waste through heating compaction. The condition factors studied were compaction duration, compaction pressure, concrete proportion, mixture percentage, temperature and particle size of wood flour. To enhance the water resistance of this recycled product, different water resistance treatments were discussed theoretically. The independence of production condition factors was analysed using a statistic method. Results indicated that within a certain range, an increase in compaction duration, compaction pressure, the percentage of wood waste and temperature improves the bending strength of the recycled products. Using smaller particle size of wood flour cannot improve compaction but contribute to give higher bending strength. The mechanical properties of these recycled products suggest application as non-bearing building material, such as decoration tiles and bricks for partition walls. The application as a structural material is expected in the future as improvement treatments are discovered.

Although Britain is relatively rich in natural aggregate reserves, planning approvals to develop new quarries are running at about half the rate of aggregate extraction. The use of secondary materials, such as recycled aggregate, might not create a major course of aggregate but if secondary material were used in less demanding situations, the quantity of natural aggregate required by the construction industry would be reduced. This dissertation reports mainly on laboratory tests conducted on crushed concrete and demolition debris to examine the potential use of these materials in new construction. Standard aggregate tests were conducted on the materials to check their compliance with the Specification for Highway Works (1986), particularly for use as aggregate in road sub-base layers. A more detailed examination of the aggregates was conducted with regard to CBR, shear strength and frost susceptibility where the influences of moisture content, density and particle packing on these properties were investigated. One part of the study involved examining the use of recycled aggregate as the coarse aggregate fraction in new concrete. An analysis of the shear strength data was conducted using the dilatancy index defined by Bolton (1986). From the frost susceptibility results, it was concluded that further work would be required in this area to determine the main factors which influence the frost heave of recycled aggregates. The recycled aggregate concrete compared well with the natural aggregate concrete and appeared to be of superior quality than that produced in other research. During the study, it became evident that the recycled aggregates could perform as well as limestone in most cases and therefore could be considered for many potential uses. Some recommendations are presented at the end of this dissertation for the development of a standard on recycled materials which would help to promote the use of recycled aggregates in the construction industry in Britain.

Thesis (MScEng)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: A major challenge for our society is the protection of the environment. Some of the important issues are the reduction in the consumption of energy and natural raw materials, as well as the increase in consumption of waste materials. At present these topics are getting considerable attention as part of sustainable development programs. The use of recycled concrete aggregates (RCA) from construction and demolition waste (C&DW) in construction, as alternative to virgin (natural) aggregates, has strong potential. The use of RCA preserves natural resources and reduces the space required for the disposal of RCA in landfill. It is estimated that 16 thousand million (billion) tons of concrete (and 25 billion tons of aggregate) were used in 2010. Of the 2-3 billion tons of C&DW which are produced worldwide every year, South Africa contributes 5-8 million tons. This amount is increasing rapidly every year. Significant amounts of demolished concrete find their way to landfill sites. A solution for excess waste production would be the utilization of RCA together with an improvement in the final quality of RCA. It might be an important breakthrough for our society in our attempt towards sustainable development. Worldwide, infrastructure has developed a great deal since the beginning of the twentieth century. Much of the core infrastructure, including roads, bridges, water systems, and sewers, was put in place during the first half of that century. Aggregates used as construction materials, as for instance in road pavements, or as an ingredient of concrete, are important components of infrastructure. Urbanization involves reduction of natural aggregate (NA) resources, but environmental concern and the rising cost of NA is the reason that recycled materials from different sources (like roads, buildings) are being used more and more with NA in new construction work. Environmental awareness is increasing in every country for many reasons and sustainable development is demanded of all industries, including the building and construction industries. By nature, construction is not environmentally friendly, and sometimes it also changes the behavior of nature in many ways. Recycling is one of the most important ways to minimize the waste that comes from different sources, thereby avoiding repetition of, and additional environmentally hazardous practices. It may create new wealth by diminished transport and production costs and sparing of landfill site space and cost. It has the potential to extend the life of natural resources by adding a source of material, thereby reducing environmental interference and impacting on nearby construction sites, all of which improve sustainability of our natural resources. Much research on the uses of RCA has been performed during the last few decades. In fact, most of them showed that the strength class of recycled aggregate concrete (RAC) is adequate for use as structural concrete although volume changes in and durability performance of RAC in comparison with natural aggregate concrete (NAC) are still being debated and researched. Some researchers found that the durability of concrete produced with RCA is inferior, but others have found it to be sufficient for use in structural concrete. The fact that an insufficient number of studies have been carried out on the durability aspects, has limited the use of RCA as material for road construction. The aim of this study is to determine the suitability of using the RCA in structural concrete based on its strength, stiffness, dimensional stability and durability. Three types of RCA designated RCA1, RCA2 and RCA3 in this study, were taken from three different sources. These materials were tested to establish their mechanical characteristics for use as aggregates in concrete. In the experimental program RCA was used at replacement percentages of 0%, 30% and 100% to (partially) replace NA in order to study its suitability as aggregate in concrete, and to what level of NA replacement its behavior is satisfactory for structural application. A single compressive strength class was studied, due to the limited time. By performing tests of compressive strength, Young’s modulus, creep, shrinkage, and durability performance, it has been found that selected types of RCA show a real possibility for use as aggregate in concrete. When concrete with a RCA replacement of 100% was compared with NAC100% there was a small decline in strength, but when concrete with a RCA replacement of 30% was compared with NAC100% the results showed almost equal strength. A slight reduction in durability performance was found for RAC30% compared with NAC100%, but similar dimensional stability performance in terms of specific creep and drying shrinkage was measured for RAC30% and NAC100%. Based on detailed experimental results obtained from this thesis project, a number of recommendations have therefore been made for RCA characteristics that will be used in concrete mixes also taking into account the quality of RCA. Some suggestions are proposed based on the mechanical properties and durability of the concrete. In the final conclusions, future studies on RCA properties are suggested, which would help us in increasing our knowledge in the application of RCA, and which may lead to the optimal production of structural concrete in a sustainable way. In general the use of RCA in concrete is feasible and good quality RCA at 30% replacement of NA may be suitable for any kind of structural concrete.
AFRIKAANSE OPSOMMING: ‘n Groot uitdaging vir ons samelewing is die beskerming van die omgewing. Van die belangrike sake is die vermindering in die verbruik van energie en van natuurlike, onverwerkte materiale asook die groter verbruik van afvalmateriaal. Hierdie onderwerpe kry tans aanienlike aandag as deel van volhoubare ontwikkelingsprogramme. Die gebruik van betonaggregate, herwin vanaf konstruksie-en slopingsafval, en gebruik in konstruksie as alternatief vir ongebruikte natuurlike aggregate, het goeie potensiaal. Die gebruik van herwonne aggregaat beskerm natuurlike hulpbronne en verminder die oppervlakte en volume wat nodig is vir die weggooi daarvan op stortingsterreine. Dit is beraam dat 16 duisend miljoen (biljoen) ton beton (en ongeveer 25 biljoen ton aggregaat) gedurende 2010 gebruik is. Van die 2-3 biljoen ton konstruksie-en slopingsafval wat jaarliks wêreldwyd gegenereer word, dra Suid Afrika 5-8 miljoen ton by. Hierdie hoeveelheid word elke jaar vinnig meer. Beduidende hoeveelhede gesloopte beton beland elke jaar op stortingsterreine. ‘n Oplossing vir die probleem van te veel atval generering sou wees die gebruik daarvan as herwonne beton-aggregaat, sou saamval met ‘n verbetering in die uiteindelike kwaliteit van herwonne aggregaat beton. Dit kan dalk ‘n belangrike deurbraak wees vir ons samelewing in ons strewe na volhoubare ontwikkeling. Infrastruktuur het wêreldwyd baie ontwikkel sedert die begin van die twintigste eeu. Baie van die kerninfrastruktuur insluitende paaie, brue, waterstelsels en riole is gebou tydens die eerste helfte van daardie eeu. Aggregaat gebruik as konstruksiemateriaal, byvoorbeeld in padplaveisels of as’n bestanddeel van beton, is ‘n belangrike deel van infrastruktuur. Verstedeliking veroorsaak vermindering van natuurlike aggregaat hulpbronne maar besorgdheid oor die omgewing en die stygende koste van nataurlike aggregaat veroorsaak dat herwonne materiale vanaf verskillende bronne (soos paaie en geboue) meer en meer aanvullend tot natuurlike aggregaat in nuwe konstruksiewerke gebruik word. Omgewingsbewustheid is om baie redes aan die toeneem in elke land en volhoubare ontwikkeling word vereis van alle industrieë. Herwinning is een van die hoofmaniere om afval vanaf verskillende bronne tot ‘n minimum te beperk. Dit skep nuwe rykdom, verminder vervoeren vervaardigingskoste en benut afval wat anders op stortingsterreine verlore sou gegaan het. Dit het die potensiaal om die lewensduur van natuurlike hulpbronne te verleng deur ‘n materiaalbron by te voeg, deur inmenging in die omgewing te verminder, wat almal bevorderlik is om volhoubare benutting van ons hulpbronne te verbeter. Baie navorsing is gedurende die laaste paar dekades gedoen aangaande die gebruik van herwonne aggregaat. Die meeste van die navorsing het inderdaad getoon dat die sterkte van beton met herwonne aggregaat genoegsaam is vir gebruik as struktuurbeton alhoewel daar wel debatte gevoer word oor die volumeveranderings en duursaamheid prestasie van herwonne aggregaat beton vergeleke met dié van natuurlike aggregaat beton. Sommige navorsers het bevind dat die duursaamheid van beton wat met herwonne aggregaat gemaak is, minderwaardig is maar andere het bevind dat dit voldoen aan die vereistes van struktuurbeton. Slegs die feit dat daar onvoldoende toetse rakende duursaamheid gedoen is, het die gebruik van herwonne beton aggregaat beperk tot padboumateriaal. Die doel van hierdie navorsing is om te bepaal wat die geskiktheid van herwonne betonaggregaat is vir gebruik in struktuurbeton, gegrond op sterkte en duursaamheid. Drie soorte herwonne betonaggregaat wat in hierdie studie as RCA1, RCA2 and RCA3 aangedui word, is elk vanaf ‘n ander bron geneem. Hierdie materiale is getoets om hulle meganiese kenmerke vas te stel vir gebruik as aggregaat in beton. In die eksperimentele program is 0%, 30% en 100% herwonne betonaggregaat gebruik om natuurlike aggregaat gedeeltelik be vervang om sodoende die geskiktheid as betonaggregaat te bestudeer. Deur toetse uit te voer op ‘n beperkte sterkte-klas beton, soos toetse vir die bepaling van druksterkte, Young’s modulus, kruip, krimp en duursaamheid, is daar bevind dat sekere soorte herwonne betonaggregaat heel moontlik gebruik kan word in struktuurbeton. Toe beton met 100% herwonne betonaggregaat vergelyk is met beton met 100% natuurlike aggregaat, is bevind dat daar ‘n klein vermindering in sterkte was, maar waar beton met 30% herwonne betonaggregaat vergelyk is met beton met 100% natuurlike aggregaat, het die resultate byna dieselfde sterkte getoon. Dus op grond van gedetaileerde eksperimentele resultate is ‘n aantal aanbevelings gemaak vir kenmerke van herwonne betonaggregaat wat in betonmengsels gebruik sal word met inagneming van die gehalte van herwonne betonaggregaat. Die resultate vir beton met 30% en 100% herwonne betonaggregaat word vergelyk met beton wat slegs natuurlike aggregaat bevat. Sekere voorstelle gegrond op meganiese eienskappe en duursaamheid van die beton word gemaak, asook aanbevelings vir toekomstige studies van herwonne betonaggregaat wat ons sal help om ons kennis vir die toepassing van herwonne betonaggregaat uit te brei.

A maioria dos processos de fabricação de um produto geram resíduos. Quando não se dispõem de uma tecnologia para o seu reaproveitamento, certamente este material será depositado na natureza e poderá ocasionar inúmeros problemas ambientais. Este trabalho trata da reutilização dos resíduos de concreto como agregado, para dosagens de concreto estrutural. Na maioria das vezes, os agregados provenientes de resíduos são considerados materiais de baixa qualidade, isso ocorre pelo desconhecimento de suas propriedades e da tecnologia para seu emprego. Fazendo uma pesquisa bibliográfica, teórica e experimental, o objetivo deste estudo foi de uma maneira informativa, contribuir para o entendimento do material, caracterizando algumas propriedades do agregado e do concreto reciclado.
Most of making process of a product produces residue. When there isn\'t a technology to use it again, certainly this material will be deposited in nature and it can bring about countless environmental problems. This work presents the reuse of concrete residues as aggregate, for dosage of structural concrete. Most of times, the aggregates provenient from the residues are considered low quality materials, it occurs due to the lack of knowledge of its properties and technology for its use. Doing a bibliographical, theorical and experimental research, the objective of this study was, on an informative way, to contribute for understanding of the material, characterizing some properties of aggregate and the recycled concrete.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
SINDUSCON-NH - Sindicato das Indústrias da Construção Civil Novo Hamburgo
A construção civil atualmente é a indústria com maior crescimento no Brasil, fomentada por financiamentos e programas do governo federal. É também uma das indústrias que mais consome recursos naturais e energia, além de ser a principal geradora de resíduos sólidos urbanos. Grande parcela destes recursos naturais consumidos pela construção é formada pelos agregados. Uma alternativa econômica e ambientalmente correta, para diminuir a extração deste material, é a sua substituição por algum outro material, se possível por um resíduo, como apontam várias pesquisas. A busca por materiais e produtos ecologicamente corretos está em uma crescente, assim como os estudos para a reciclagem de diversos resíduos. A união entre produtos que consomem um volume menor de matéria-prima com o emprego de resíduos na sua produção parece uma saída viável para um desenvolvimento mais sustentável. Artefatos para a construção civil produzidos com concreto celular autoclavado (CCA) utilizam até quatro vezes menos materiais quando comparados a produtos com características semelhantes, produzidos com concreto convencional, cerâmico, entre outros. Além do menor consumo dos materiais constituintes, o concreto celular possui outras propriedades interessantes, como: suficiente resistência à compressão; isolamento térmico e acústico; baixa densidade; resistência ao fogo. Esta pesquisa teve como objetivo principal avaliar a influência da substituição parcial do agregado natural por agregado reciclado de concreto (ARC) na produção de concreto celular autoclavado. Após realização de estudos-piloto, optou-se pelo emprego da proporção de Cimento e Agregado Natural (AN) de 67% e 33% e sobre estes 0,45% de Cal e 0,3% de Alumínio com relação água/sólidos igual a 0,32. Foram empregados Cimento Portland CP-V ARI, Cal calcítica, areia natural e agregado fino reciclado de concreto, em teores de 0%, 25% e 50%. A dimensão máxima do agregado empregado na produção de CCA é de 150 µm. A cura foi realizada em autoclave após um tempo de espera de 24 horas a partir do início da mistura, por um período de 6 horas. Foram avaliadas a resistência à compressão, a absorção de água capilar, a massa específica e a porosidade. Os ensaios de resistência à compressão foram realizados em 48 e 72 horas, e a absorção de água, em corpos de prova preparados e acompanhados pelo período de 96 horas. A microestrutura dos CCA produzidos foi caracterizada por microscopia eletrônica de varredura (MEV). Verificou-se que existem expressivas alterações nas propriedades do CCA produzidos com ARC em substituição do AN, com a tendência de aumentar a densidade de massa aparente, bem com a resistência à compressão, a medida que aumenta-se o teor de ARC. Na análise dos resultados, percebeu-se que o uso de ARC alterou as propriedades dos concretos produzidos neste estudo exploratório, sem, entretanto, inviabilizar o seu emprego. Com um ajuste da dosagem, pode ser obtido um CCA produzido com ARC, cujo comportamento seja compatível com o comportamento de CCA produzido somente com o AN.
In the last years, the Brazilian construction industry is among those of national production sectors that have been having a great growing, mostly due to the incentive from the government and due to financed resources by private and public agents. This industry is also one of the major consumers of natural resources and energy, besides being the main generator of solid waste. One of these natural resources used in the constructions is sand. An environmentally friendly and economical alternative to reduce the extraction of natural resources is the use of recycled waste. The associated use of low volume of raw materials with alternative materials, like waste, is one of the ways to get more sustainability in the construction sector. Construction and building components made with autoclaved cellular concrete (ACC) employ four times less material than others with the same function. Other advantage of ACC is the performance of its properties like compressive strength, thermal and acoustic behavior, lower density, fire resistance. The aim of this research was to investigate the use of fine grains from recycled concrete aggregate (ARC) as partial sand replacement in the production of autoclaved aerated concrete. With the goal to find the mix proportion some pilot studies were made. After this, it was chosen a relation of 67% of cement and 33% of natural fine aggregate (sand). The lime was used in the amount of 0.45% of total cement and sand, and 0.3% of aluminium. The water to total solids ratio was 0.32. It was employed Portland cement type V according to Brazilian standards, calcitic lime, natural sand and ARC passing in sieve with 150 micron opening. The replacement rate of sand by ARC was 0%, 25% and 50%. From 24 hours after the mixing of materials, the samples were submitted to steam curing in an autoclave chamber for 6 hours. It was evaluated the compressive strength, the density, the capillary water absorption and porosity. The compression strength tests were performed at 48 and 72 hours. Water absorption tests were conducted for 96 hours after samples preparing. The capillary porosity was calculated with the capillary water absorption data. ACC's microstructure analysis was done by scanning electron microscopy (SEM). The results showed in general that the behavior of ACC produced with ARC differs significantly from the ACC produced with natural aggregate. When the ARC rate increases the apparent specific gravity also increases as well as the compressive strength. The observed increase in the apparent specific gravity is not desired. However this behavior of ACC done with RCA does not prevent the use of this recycled aggregate. An optimized study of pre-wetting of RCA could improve its performance as aggregate for use in ACC, once its grain size showed to be appropriated for this kind of use.

This report aims to investigate why proven methods for recycling concrete waste as road construction material are not practiced in Sweden. An additional objective is to investigate how concrete is handled as a waste product and whether it would be environmentally friendly and financially beneficial to clients and contractors. Information has been extracted via interviews conducted with experts from various positions within the civil engineering industry. Additional information was obtained through literature studies and questionnaires sent and received via email. Results which were frequently mentioned by engineering professionals included the extra expense of transporting and processing crushed concrete, parties involved in the design and construction processtend to follow traditional methods of using tried and tested virgin materials, the assumption of responsibility for structural failure due to alternative materials and general lack of knowledge surrounding crushed concrete as a construction material. Conclusions are that crushed concrete is suitable for construction of subbases in roads and base courses of cycle/pedestrian paths. Traditionally used virgin materials are generally less expensive than crushed concrete. Existing legislation makes the use of recycled construction material difficult. Awareness and education regarding recycled concrete, as a construction material, should be increased.

The purpose of this work is to find a methodology in order to make possible the recycling of fines (0 - 4 mm) in the Construction and Demolition Waste (CDW) process. At the moment this fraction is a not desired by-product: it has high contaminant content, it has to be separated from the coarse fraction, because of its high water absorption which can affect the properties of the concrete. In fact, in some countries the use of fines recycled aggregates is highly restricted or even banned. This work is placed inside the European project C2CA (from Concrete to Cement and Clean Aggregates) and it has been held in the Faculty of Civil Engineering and Geosciences of the Technical University of Delft, in particular, in the laboratory of Resources And Recycling. This research proposes some procedures in order to close the loop of the entire recycling process. After the classification done by ADR (Advanced Dry Recovery) the two fractions "airknife" and "rotor" (that together constitute the fraction 0 - 4 mm) are inserted in a new machine that works at high temperatures. The temperatures analysed in this research are 600 °C and 750 °C, cause at that temperature it is supposed that the cement bounds become very weak. The final goal is "to clean" the coarse fraction (0,250 - 4 mm) from the cement still attached to the sand and try to concentrate the cement paste in the fraction 0 - 0,250 mm. This new set-up is able to dry the material in very few seconds, divide it into two fractions (the coarse one and the fine one) thanks to the air and increase the amount of fines (0 - 0,250 mm) promoting the attrition between the particles through a vibration device. The coarse fraction is then processed in a ball mill in order to improve the result and reach the final goal. Thanks to the high temperature it is possible to markedly reduce the milling time. The sand 0 - 2 mm, after being heated and milled is used to replace 100% of norm sand in mortar production. The results are very promising: the mortar made with recycled sand reaches an early strength, in fact the increment with respect to the mortar made with norm sand is 20% after three days and 7% after seven days. With this research it has been demonstrated that once the temperature is increased it is possible to obtain a clean coarse fraction (0,250 - 4 mm), free from cement paste that is concentrated in the fine fraction 0 - 0,250 mm. The milling time and the drying time can be largely reduced. The recycled sand shows better performance in terms of mechanical properties with respect to the natural one.

O estudo da reciclagem de pavimentos de concreto para utilização em novos pavimentos tem se mostrado de grande importância haja vista a quantidade de materiais necessários para a reconstrução dessas vias. Além do ganho ambiental, devido a uma menor extração de agregados, obtém-se um ganho econômico, com menor custo de transporte e de aquisição de materiais. O agregado proveniente da britagem de antigas placas de concreto se mostrou, historicamente, apto a ser utilizado para a produção de um novo pavimento de concreto. Entretanto, existem certas limitações, pois o seu uso não resulta em um concreto com características totalmente idênticas àquelas do concreto convencional. O presente trabalho apresenta resultados da análise das características dos agregados produzidos através da britagem de antigas placas de pavimentos de concreto do Rodoanel Metropolitano Mário Covas em britador de mandíbula e em britador de impacto, bem como a influência do uso de agregados reciclados nas propriedades mecânicas do concreto. No estudo comparativo entre os tipos de britador foi verificado que agregados obtidos por britador de mandíbula e por britador de impacto possuem características muito semelhantes. No estudo das características mecânicas dos concretos a resistência à tração na flexão, a resistência à tração na compressão e o módulo de elasticidade diminuíram conforme se aumentou a absorção de água ponderada dos agregados. No que se refere à resistência à compressão, contudo, não foi observada queda ao se substituir somente a fração de agregados graúdos na mistura. Quando se procedeu com a substituição da fração miúda, porém, a resistência ficou abaixo daquela do concreto de convencional.
The study of concrete pavement recycling for its use in new pavements has shown to be of great importance considering the quantity of materials that are necessary to reconstruct these roads. Besides the environmental gain, due to a lesser extraction of aggregates, there is also an economic gain, with smaller transportation and material purchasing costs. The aggregate originated from the crushing of old concrete slabs has historically been shown to be able to be employed in the construction of a new concrete pavement. However, there are limitations, since its utilization does not result in a concrete with the exact same properties of the conventional concrete. The present work presents the results from the analysis of the characteristics from the aggregates produced through the crushing of old concrete slabs using a jaw crusher and an impact crusher, as well as the influence of the use of recycled aggregates on the concrete mechanical properties. The crusher type comparative study has shown that aggregates obtained from a jaw crusher and from an impact crusher have very similar characteristics. The concrete mechanical characteristic study reveals that flexural strength, indirect tensile strength and modulus of elasticity decrease as the aggregates water absorption increase. Concerning compressive strength, however, there was no observed decrease when only coarse recycled aggregates were used. Nevertheless, when fine recycled aggregates were employed besides coarse recycled aggregates, there was a decrease in compressive strength.

Thesis (MScEng)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The aim of this research is to investigate the potential use of coarse recycled concrete aggregate (RCA) as a material in structural concrete. The lack of knowledge and specifications in South Africa are the main reasons for this research of RCA. By increasing the database of research of RCA in South Africa the possibility of specifications for this alternative building material can be initiated. The implications of such specifications would lead to RCA acceptance in concrete design and therefore reducing the amount of construction and demolition (C&D) waste accumulating at landfill sites and decreasing the extraction of depleting natural aggregates. The objectives that are achieved through this research project are firstly, what is the percentage replacement of RCA to a concrete blend that will produce a material that achieves similar or better results than a concrete blend containing natural aggregates. Secondly, what aggregate properties and limits should be defined in the specification of RCA for it to be accepted as a material in concrete mixtures. The objectives were assessed through examining the geometrical, physical and chemical properties of the aggregate as a material and the fresh and hardened concrete properties of concrete which contains RCA as a constituent. RCA which was processed by a commercial recycling facility which produces concrete masonry units was collected at three different instances. This material was reprocessed in the laboratory to control the grading and amount of fine material not guaranteed by the recycling process. The RCA is then combined with natural aggregate (NA) at the replacement percentages: 0, 15, 30, 50 and 100% which is then used to examine the aggregate properties. It was determined that the physical properties of RCA were dependent on the geometrical properties, while taking into consideration that the geometrical properties are dependent on the source and method of recycling of the original C&D waste. The chemical properties were established as dependent on the physical properties of the RCA. The RCA is then mixed with NA at the same replacement percentages together with other concrete constituents to produce the concrete used to examine fresh and hardened concrete properties. The fresh concrete properties investigated were: slump, slump loss, air content and fresh compacted density. The hardened concrete properties studied were: compressive strength, tensile splitting strength, oxygen permeability, water sorptivity, chloride conductivity, modulus of elasticity, shrinkage and creep. The concrete properties were not significantly influenced by the inclusion of RCA. According to the aggregate and concrete properties examined in this investigation, the full replacement of NA in structural concrete is possible and will improve the sustainable development of the construction industry.
AFRIKAANSE OPSOMMING: Die doel van hierdie navorsing is om ondersoek in te stel na die potensiele gebruik van growwe herwonne betonaggregaat (RCA) as ‘n materiaal in betonstruktuurontwerp. Die gebrek aan kennis en spesifikasies in Suid Afrika is die vernaamste rede vir hierdie navorsing van RCA. Deur die vermeerdering van die databasis van hierdie navorsing van RCA in Suid-Afrika kan die moontlikheid van spesifikasies vir hierdie alternatiewe boumateriaal geïnisieer word. Die implikasie van sodanige spesifikasies sou lei tot RCA aanvaarding in betonontwerp en dus die vermindering van die hoeveelhede konstruksie en sloping (C&D) van afvalversameling by stortterreine en om die ontginning van natuurlike aggregate te verminder. Die doelwitte wat deur hierdie navorsingsprojek bereik word is eerstens, wat is die vervangings persentasie van RCA in 'n betonmengsel wat produseer word wat dieselfde of beter resultate sal lewer as 'n betonmengsel wat uit natuurlike aggregate bestaan. Tweedens, watter aggregaat eienskappe en beperkings moet gedefinieer word in die spesifikasie van RCA sodat dit aanvaarbaar is as ‘n materiaal in betonstruktuur ontwerp. Die doelwitte word geassesseer deur die ondersoek van die geometriese, fisiese en chemiese eienskappe van die aggregaat as ‘n wesenlike materiaal en die vars en verharde betoneienskappe van RCA as ‘n bestanddeel in struktuurbetonontwerp. RCA monsters was geneem by ‘n kommersiele herwinningsfasiliteit wat RCA gebruik om betonsteen eenhede te vervaardig, is op drie verskillende tydperke ingesamel. Hierdie materiaal is herverwerk in die laboratorium om die gradering en die hoeveelheid van fyn materiaal wat nie deur die herwinningsproses beheer is nie. Die RCA was dan gekombineer met NA teen vervangingspersentasies van: 0, 15, 30, 50 en 100 % wat dan gebruik was om die eienskappe van die aggregaat te ondersoek. Daar is vasgestel dat die fisiese eienskappe van die RCA afhanklik van die geometriese eienskappe, met inagneming dat die geometriese eienskappe afhanklik is van die bron en metode van die herwinning van die oorspronklike C&D afval. Dit is gestig dat die chemise eienskappe is afhanklik van die fisiese eienskappe van die RCA. Die RCA is toe gemeng met NA teen dieselfde vervangingspersentasies saam met ander beton bestanddele om beton te produseer wat dan vergelyk kan word met vars en verharde beton eienskappe. Die volgende vars betoneienskappe is ondersoek: insinking, insinking verlies, luginhoud en vars gekompakteerde digtheid. Die volgende verharde betoneienskappe is bestudeer: druksterkte, trek die splintsing van krag, suurstofpermeabiliteit, water sorptiwiteit, chloride geleidingsvermoё, modulus van elastisiteit, krimp en kruip. Die beton eienskappe was nie beduidend beïnvloed deur die insluiting van RCA nie. Volgens die aggregate en beton eienskappe wat in hierdie navorsing ondersoek is, blyk dit dat die volle vervangingswaarde van NA in strukturele beton moontlik is en die volhoubare ontwikkeling van die konstruksiebedryf sal verbeter.

Thesis (MEng)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: The global quest for sustainability has intensified the requirement for waste recycling in a number of countries. Waste recycle includes Construction and Demolition Waste (CDW), which emanates from the demolition of buildings and other civil engineering structures. In Europe, the United States, China, and Australia, waste recycling has proven to be successful, both structurally and functionally. In particular, the consideration and /or use of CDW in pavement layers remain on the increase. However, in Southern Africa the use and/or application of CDW and its allied practice is limited; the abundant natural aggregates, the lack of knowledge and technical expertise besides the availability of suitable CDW remain the prominent reasons for its limited consideration. In this research, recycled material infers to Construction and Demolition Waste pertaining to Recycled Concrete and Masonry (RCM). The quality and the type of RCM vary from region to region and as a result, quality control measures aimed at limiting the inconsistency are usually required. Results revealed that secondary crushing influences the physical and mechanical behaviour of RCM aggregates; this information remains insightful in terms of material gradation, performance and viability. The compaction protocol followed and its findings revealed that the initial material grading lightly changed after compaction. However, the 10% FACT results showed that the RCM aggregates exhibit less degradation due to crushing when dry than when they are wet. It is eminent that compaction and/or densification are a cheaper method to improve the pavement layer structural capacity. However, this is reliant on material characteristics, quality, and type. With this cognisance, an experimental program in line with RCM aimed at assessing the mechanical behaviour was developed. The experimental variables include mix composition, mixing and compaction moisture as well as degree of compaction and/or compactive effort. In general, the laboratory evaluation and analysis of the results showed that the mix composition in addition to compaction moisture and the degree of compaction were influential to the obtained shear strength, resilient modulus and Poisson Ratio. Particularly, mix composition exhibited relatively higher influence on the resilient modulus while the compaction moisture effect on the Poisson Ratio dominated other investigated variables such as mix composition and the degree of compaction. Shear strength and resilient response results show that RCM exhibits significant shear strength due to its cohesion, and satisfactory resilient modulus. Pavement analysis and design using multi-layer linear-elastic model and transfer functions in pavement layers where RCM is used also revealed that this material could perform satisfactorily. It was deduced that RCM is a viable material type to consider in the construction of pavement layers that carry low to moderate levels of traffic.
AFRIKAANSE OPSOMMING: Die globale beweging na meer onderhoubare aktiwiteite het gelei tot die ʼn toename in vereistes met betrekking tot herwinning van rommel. Rommelherwinning sluit materiaal van bouwerke en ander siviele strukture in. In Europa, Amerika, China en Australië het die herwinning van afval materiaal tot groot sukses gelei. Spesifiek die gebruik van geselekteerde bourommel in padlae bleik om toe te neem. In Suid -Afrika word die materiaal net in enkele geïsoleerde gevalle gebruik as gevolg van die onderbreking van tegniese kennis met betrekking tot die toeganklikheid en bruikbaarheid van die materiaal. Ook, tans geniet die gebruik van gebreekte klip voorrang omdat die verbruiker glo dat daar nog baie van hierdie materiaal beskikbaar is. In hierdie navorsing verwys bourommel spesifiek na herwinde beton en boustene. Die “kwaliteit” van boustene in verskillende gebiede varieer en as ‘n gevolg moet kwaliteitskontroles toegepas word om hierdie te beperk. Resultate in diè navorsing het gewys dat sekondêre klipbreking/vergruising die fisiese en meganiese gedrag van “bourommel aggregaat” beïnvloed. Die 10% FACT (Fynstof Aggregaat Breekwaarde) resultate het ook gewys dat geselekteerde bourommel minder degradasie ondervind as dit droog is in vergelyking met nat materiaal. Goeie kompaksie van die tipe materiale word erken as een van die goedkoopste maniere om die gedrag daarvan in plaveisellae te verbeter. Dit is wel afhanklik van materiaal karakteristieke, kwaliteit en tipe materiaal. Hierdie faktore is ingesluit in die eksperimentele plan wat eienskappe soos mengsel komposisie, meng en kompaksie voginhoud sowel as graad van kompaksie insluit. Die resultate van die laboratorium analise het gewys dat die mengkomposisie, vog tydens kompaksie en graad van kompaksie ʼn invloed op die skuifsterkte, veerkragsmodulus en die Poisson verhouding het. Veral die mengkomposisie het ʼn merkwaardige invloed op die veerkragmodulus gehad, terwyl die voginhoud tydens kompaksie die grootste invloed op die Poissonverhouding gehad het. Die skuifsterkte (agv hoë kohesie) en veerkragsmodulus van geselekteerde bourommel dui aanvaarbare resultate vir die gebruik in paaie, spesifiek in padlae waar lae spanningsvlakke ondervind word,soos deur liniere elastiese berekeninge gewys is.

Storage of mine tailings and waste concrete imposes economical and environmental impacts. Researchers have attempted to reuse wastes as construction material by utilizing ordinary Portland cement (OPC) to stabilize them. This method, however, has a number of limitations related to OPC. In this research, a recent technology called geopolymerization is used to stabilize mine tailings and concrete waste so that they can be completely recycled and reused. The research includes three main parts. The first part studies the effect of different factors on the mechanical properties, micro/nano structure, and elemental and phase composition of mine tailings-based geopolymer binder. The second part investigates the feasibility of producing geopolymer bricks using mine tailings. The physical and mechanical properties, micro/nano structure, durability, and environmental performance of the produced bricks are studied in a systematic way. Moreover, the enhancement of the mine tailings-based geopolymer bricks by adding cement kiln dust (CKD) is studied. The third part of the research investigates the recycling of the fines fraction of crushed waste concrete to produce binder through geopolymerization in order to completely recycle concrete waste. The results indicate the viability of geopolymerization of mine tailings by optimizing the synthesis conditions. By properly selecting these factors, mine tailings-based geopolymer bricks can be produced to meet the ASTM standard requirements and to be environmentally safe by effectively immobilizing the heavy metals in the mine tailings. The physical and mechanical properties and durability of the mine tailings-based geopolymer bricks can be further enhanced by adding a small amount of CKD. The results also show that the fines fraction of crushed waste concrete can be used together with fly ash to produce high performance geopolymer binder. Incorporation of calcium in the geopolymer structure and coexistence of the calcium products such as CSH gel and the geopolymer gel explains the enhancement of the mine tailings-based geopolymer bricks with CKD and the high performance of geopolymer binder from the waste concrete fines and fly ash. The research contributes to sustainable development by promoting complete recycling and utilization of mine tailings and concrete waste as construction material.

Orientador: Vladimir Antonio Paulon
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-19T19:32:15Z (GMT). No. of bitstreams: 1 Meneguini_EduardoCesarAntonelli_D.pdf: 4162044 bytes, checksum: 987787614d2ef9437a3937a43815bde9 (MD5) Previous issue date: 2011
Resumo: O principal objetivo deste trabalho é a determinação das principais propriedades do asfalto borracha e das propriedades mecânicas de um concreto asfáltico, tendo, como adição, o uso de borracha moída de pneus usados, tratada com solução de hidróxido de sódio comercial. Obtivemos, com o tratamento superficial da borracha de pneus usados, melhor interface entre a borracha e asfalto, assim como com o concreto asfáltico e a borracha, alcançando sensível aumento da durabilidade do asfalto-borracha. Realizamos, primeiramente, ensaios para caracterizar o asfalto-borracha tratado de acordo com as Normas vigentes, ensaios de durabilidade e, em seguida, ensaios mecânicos do concreto asfáltico. A recuperação elástica do asfalto-borracha utilizando pó de borracha tratada com hidróxido de sódio aumentou em 10% quando comparados com asfalto-borracha sem tratamento. Os resultados demonstraram melhora da estabilidade à estocagem em 42% nos ensaios realizados. Os ensaios de envelhecimento demonstraram que o tratamento do pó de borracha com hidróxido de sódio aumentou sensivelmente sua durabilidade. O ensaio de variação de massa, após o ensaio de envelhecimento, demonstrou que a perda de massa dos corpos de prova utilizando pó de borracha tratada com hidróxido de sódio foi 111% melhor quando comparados com os corpos de prova utilizando pó de borracha sem tratamento. Concluímos que há grande aplicabilidade deste asfalto-borracha na construção civil
Abstract: The main objective of this study is to determine the main properties of the asphalt-rubber and the mechanical properties of an asphalt concrete, with the addition of ground rubber from second-hand tires, treated with a sodium hydroxide commercial solution. We obtained, with the superficial treatment of rubber from second-hand tires, a better interface between the rubber and the asphalt, as well as with the asphalt concrete and the rubber, achieving significant increase in the durability of the asphalt-rubber. We undertake tests to characterize the treated asphalt-rubber according to current standards, durability tests, and then mechanical tests of the asphalt concrete. The elastic recovery of the rubber asphalt with rubber powder treated with sodium hydroxide increased by 10% compared to the untreated rubber asphalt. The results showed an improved stability to storage in 42% in the tests. The aging tests showed that the treatment of the rubber powder with sodium hydroxide significantly increased their durability. The mass change test after the aging test showed that the mass loss of the specimens with rubber powder treated with sodium hydroxide was 111% better when compared to the specimens with rubber powder without treatment. We conclude that there is great use of this rubber asphalt in the construction industry
Doutorado
Saneamento e Ambiente
Doutor em Engenharia Civil

Os resíduos de concreto apresentam grande potencial para serem reciclados quando comparados com outros resíduos, entretanto, o número de estudos realizados no Brasil é muito pequeno dificultando a utilização deste material em dosagens estruturais. Em virtude disso, desenvolveu-se um estudo teórico-experimental visando caracterizar algumas propriedades do agregado e do concreto reciclado; no estudo teórico exploraram-se aspectos relacionados à geração, deposição, processos para recuperação, britagem, casos práticos, pesquisas envolvendo reciclados de concreto e as recomendações normativas existentes. No desenvolvimento experimental, analisou-se a influência do período decorrido entre a moldagem e a reciclagem do concreto nas propriedades dos agregados e concretos. Os resultados indicam que resíduos reciclados logo após sua geração, contribuem positivamente para as propriedades mecânicas do concreto, devido à existência de grande quantidade de partículas não-hidratadas de cimento, tais concretos obtiveram resultados superiores para a resistência à compressão e tração quando comparados aos concretos com agregados naturais.
The concrete residues show a large potential to be recycled when compared with other residues; however, the number of studies in Brazil is very small hindering the use of this material in structural dosage. By virtue of that, it was developed a theoretical-experimental study to characterize some properties of aggregate and recycled concrete; in the theoretical study it was explored aspects related to the generation, deposition, processes for recovery, crushing, practical cases, researches involving recycled of concrete and the existent normative recommendations. In the experimental development, it was analyzed the influence of the period elapsed between the molding and the recycling of the concrete in the properties of the aggregates and concretes. The results indicate that residues recycled soon after generation, these contribute positively to the mechanical properties of the concrete due to the existence of large amount of nonhydrated cement particles, such concretes obtained results superiors for the compression strenght and tensile strenght when compared to the concretes with natural aggregates.

Este trabalho estuda a influência da utilização de resíduos de concreto (fração graúda ou miúda) nas características físicas e mecânicas de blocos de concreto estruturais, comparando-as com as características obtidas para blocos produzidos com agregados naturais. Foram utilizados resíduos obtidos de diferentes fontes oriundas de uma indústria de pré-moldados e pesquisados limites para a substituição dos agregados naturais por esses agregados reciclados. Inicialmente, foram realizados ensaios de caracterização dos agregados reciclados de concreto para avaliar o potencial de aplicação de cada um deles. Após serem selecionados os dois agregados mais apropriados para o estudo (resíduos de vigotas e blocos), foram produzidos corpos de prova com três traços em volume 1:20, 1:15 e 1:10, com substituições de 100% e 50% para agregados graúdos e de 33% para agregados miúdos. Quase todos esses traços e substituições foram utilizados para produzir blocos de concreto em uma indústria de pré-moldados, objetivando-se obter resistências à compressão de 4.5, 8.0 e 12.0 MPa. Os resultados obtidos para blocos com agregados reciclados foram então comparados com aqueles obtidos utilizando-se agregados naturais. Observou-se que, apesar de algumas propriedades apresentarem alterações, foram obtidos valores adequados para os parâmetros mais importantes, principalmente quanto à resistência à compressão e à absorção de água. Por fim, foram produzidos e ensaiados prismas com os blocos com agregados reciclados que apresentaram melhor desempenho, sendo avaliados a resistência à compressão e o módulo de deformação. Os resultados mostraram que os valores de eficiência prisma/bloco não foram significativamente alterados e os valores para os módulos de deformação resultaram próximos, tanto para blocos com agregados reciclados quanto para blocos com agregados naturais
This research deals with the influence of the use of recycled concrete aggregate (coarse and fine) for physical and mechanical characteristics of concrete blocks comparing them with those ones obtained from blocks produced with natural aggregates. Residues from different sources of a prefabricated concrete blocks factory were used and limits for substituting natural aggregates for recycled aggregate were tested. First, several characterization tests for different recycled concrete aggregates were carried out in order to evaluate their properties. Two of them were selected and test samples were produced considering three different mix proportions in volume: 1:20, 1:15 and 1:10, with replacements of 100% and 50% of coarse aggregates and 33% of fine aggregates. Almost all of these proportions were used for preparing concrete blocks with three classes of compression strength: 4.5, 8.0 and 12.5 MPa. Then the obtained results were compared with those ones obtained for blocks with natural aggregates. Despite the fact of the properties were not the same, the physical and mechanical characteristics could be considered adequate, mainly regarding compression and water absorption. Finally, some prisms with blocks of recycled aggregate were produced and tested evaluating the results for compression and deformation modulus. One could observe that the strength rate prism/block was not significantly modified and the deformation modulus were similar either considering blocks of recycled aggregate or blocks of natural aggregate

A redução no volume de resíduos produzidos, industriais e agrícolas, vem se tornando uma exigência constante em todos os processos de produção. A falta de espaço físico para a disposição destes resíduos, a contaminação ambiental causada por eles, além da necessidade de preservação dos recursos naturais não-renováveis e da diminuição do consumo de energia e emissão de poluentes, tornam a reciclagem e a reutilização dos resíduos uma alternativa bastante atraente. A construção civil apresenta-se como um setor bastante apto à utilização de técnicas de reaproveitamento de resíduos, provenientes das mais diversas indústrias. Além de todos os benefícios ambientais, este reaproveitamento, pela construção civil, pode gerar recursos financeiros, bem como, possibilita a melhora das características de alguns materiais de construção, e pode diminuir o custo de construção, fator importante, quando se avalia o déficit de habitacional existente no Brasil. Neste trabalho, desenvolveu-se um estudo baseado no aproveitamento de escória de aciaria elétrica, resíduo gerado a partir da reciclagem do aço, empregada como agregado para concreto de cimento Portland, em substituição total ou parcial dos materiais convencionais. Os resultados obtidos apontaram para a viabilidade de utilização deste resíduo como agregado.
The reduction on the volume of produced wastes, from industries or agriculture, is becoming a current demand in all production processes. The lack of space to dispose these wastes, the environment contamination caused by them, besides the necessity to preserve the non-renewable natural resources, to reduce energy consumption and greenhouse gas emission , are making wastes recycling and reutilization an interesting alternative. The civil construction presents itself as a field quite able to utilize techniques to reuse wastes from different industries. Besides all the environmental benefits, this reuse by the civil construction can create new profits, as well as, the improvement of the characteristics of some construction materials and it can also decrease the costs of the construction, which is a major factor, considering the Brazilian habitation deficit. In the present work a study was developed based on the reutilization of the electric arc furnace slag, a metallurgic waste from the steel recycling process, employed as an aggregate to the concrete of Portland cement, totally or partially replacing the conventional materials. The obtained results indicate this waste reutilization viability.

All around the globe the consumption of raw materials by the construction industries isaccumulating day by day resulting with an depletion of natural resources, increasing the environmental impacts and CO2 emissions all over the surroundings. Today steel and concrete are widely used and are dominating construction materials in construction industry. These two construction materials are different products and have distinct production flow with significantimpact on the environment. The amount of embodied energy and operational energy which is consumed in the process of production, recycling and reuse are becoming increasingly more important in the construction industries due to the potential shortage of natural resources in thenear by future and due to the inflation in the energy prices. This master’s thesis determines some of the problems of antagonistic environmental impacts due to the use of steel and concrete in the construction industries. To mitigatethese environmental impacts there are two technology and policy strategies summarizedin this thesis. i. Reduce consumption; andii. Material selection to reduce impacts.i. Reduce consumption: All around the globe the consumption of materials is growing day by day with an increase in the population resulting with a depletion of virgin materials. This depletion of virgin materials can be reduced with the help ofrecycling and reuse of the structural members. Recycling of structural members isalready practiced widely than reuse; reuse of the structural members additionallyreduces the consumption of virgin materials. High level of reuse of the structuralmaterials can be achieved by establishing design standards and regulations forstructural sections, and developing a market for reusable structural sections.ii. Material selection to reduce impacts: For the selection of constructionmaterials with minimum impact on the environment the designers needs tohave apropos education or tools. The main areas for augmentation areidentified as education of designers, and standardization and simplification ofselection tools like Life Cycle Assessment (LCA). Some of the main recommendations are: LCA tools standardization; reduce the impact sections and make these impact sections comprehendible and integrate uncertainty dataand educating designers about material selection tools with organized programs.

Orientador: Vitor Antonio Ducatti
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: A preocupação com o grave problema da geração de resíduos na construção civil e na indústria vem, cada vez mais, despertando a conscientização da necessidade de realização de estudos com vistas a melhorar o ciclo de produção e adequar a destinação dos resíduos gerados. Neste sentido, a reciclagem se apresenta como uma grande alternativa. Este trabalho visa a reciclagem do pó de serra da indústria madeireira que é um resíduo indesejável, tendo atualmente como única opção de uso, sua queima ou descarte final. A reciclagem deste material, vem contribuir para a formação de uma nova matéria-prima, possibilitando sua utilização como material de construção civil. É estudada a influência de diferentes teores da adição do pó de serra tratado em substituição parcial ao agregado miúdo mineral na fabricação de blocos de concreto para alvenaria de vedação e como elementos de enchimento para pré-lajes. Determinou-se a resistência à compressão, teor de umidade, absorção de água, área líquida e condutividade térmica para vários teores de pó de serra em substituição parcial e total ao agregado miúdo mineral. A análise dos resultados permite concluir que a utilização do pó de serra como agregado miúdo na confecção dos blocos de concreto até 50% em volume aumentou a resistência térmica com redução de peso, atendendo as prescrições da norma para alvenaria de vedação. Também, observa-se uma diminuição da resistência à compressão em relação ao bloco de concreto de referência. A utilização da argamassa de cimento e pó de serra como elementos de enchimento para pré-lajes, atendeu às normas brasileiras. É possível concluir, ainda, que a utilização do pó de serra em substituição parcial ou total ao agregado miúdo mineral, contribui para um programa de reciclagem, diminuindo a demanda do agregado miúdo para a confecção dos blocos de concreto e elementos de enchimento das pré-lajes
Abstract: Concern with residue from the construction industry calls upon the need for studies aiming to optimize production cycle as well as to better dispose of such residues. Evidently, recycling is certainly an excellent option. The work herein described concerns recycling of sawdust, a very undesirable residue generated by wood industries, which nowadays can only be disposed of by burning or dumping. Recycling such material engenders a new product to be used in building construction. It is studied the influence of different quantities of sawdust, partially substituting fine aggregate mineral, used to produce hollow concrete masonry blocks and elements for precast plank. Their compression load capacity, humidity, water absorption factor, net area and thermal conductivity were determined. Final results analysis leads to the conclusion that employing sawdust, up to 50% in volume, to produce concrete blocks increases their thermal isolation capacity besides reducing their total weight. However, a reduction on their compression loads capability was observed, as compared to the reference concrete blocks. Utilization of mortar of cements and sawdust as filling elements for precast plank, satisfies the brasilian norms. Thus, it is possible to conclude that the use of sawdust in partial or total substitution of the fine aggregate, contributes towards a recycling program, reducing the need for fine aggregate to produce concrete blocks and filling elements for precast plank
Mestrado
Edificações
Mestre em Engenharia Civil

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The aim of this study is to determine the possible replacement percentage of cement per waste marbles and granites (WMG) of marble shops of Manaus in the production of self-compacting concrete (SCC). The methodology adopted was to hold various laboratory tests: characterization of each constituent material of the CAA; the rheological properties of SCC; and mechanical, physical and chemical properties in the hardened state of SCC. Two superplasticizers have been applied, one on the base and other salts of sulphonated polymer based whose optimum content was determined by testing the slurry Marsh cone. The coarse aggregates and kids were characterized by assays granulometry, specific weight; unit mass in loose state; and unitary mass compressed and dry. The WMG were subjected to density testing and analysis of Fluorescence X Ray. For fresh SCC in the following tests were performed: scattering, scattering T500, V funnel and L box; and Testing of Compressive Strength and flexion, absorption, voids index and the SCC Density in the hardened state, as well as tests on mortar bars to check possible Alkali Aggregate Reaction (AAR). The results were effective for most traits SCC, up to 30% of the cement replacement by WMG when the additive polymer base was used, and up to 20% replacement when the superplasticizer was sulfonated. Fresh in this SCC met the requirements of ISO 15823, behaving like proper concrete for use in most current applications. In the hardened state near showed compressive strength of 35 MPa, may also be used in the production of concrete floors. The resistance to bending achieved in around 7.0 MPa and satisfy the Brazilian standard 15805. For absorption values were comprised between 4.0% and 5.0%, lower than the values found in the literature, for voids and density values were close to other research, 10%. In AAR tests achieved the expansion was less than 0.10%, and the waste classified as harmless by Brazilian standard 15577-4. With the above it can be said that the residues from marble shops may have an alternative destination in civil construction.
O objetivo principal deste trabalho é determinar o percentual de substituição possível de cimento por resíduos de mármores e de granitos (RMG) das marmorarias de Manaus na produção de concreto autoadensável (CAA). A metodologia adotada foi a realização de vários ensaios laboratoriais: de caracterização de cada material constituinte do CAA; das propriedades reológicas do CAA; e das propriedades mecânicas, físicas e químicas do CAA no estado endurecido. Foram aplicados dois superplastificantes, um à base de sais sulfonados e outro à base de polímeros, cujo teor ótimo foi determinado por meio de ensaios de pasta no cone de Marsh. Os agregados graúdos e miúdos foram caracterizados por meio de ensaios de granulometria, massa específica; massa unitária em estado solto; e massa unitária em estado compactado e seco. Os RMG foram submetidos a ensaio de massa específica e análise de Fluorescência de Raios X. Para o CAA no estado fresco foram realizados os seguintes ensaios: Espalhamento, Espalhamento T500, Funil V e Caixa L; e Ensaios de Resistência à Compressão e à Flexão, Absorção, Índice de Vazios e Massa Específica do CAA no estado endurecido, bem como ensaios em barras de argamassas para verificar possível Reação Álcali Agregado (RAA). Os resultados mostraram-se eficazes para a maioria dos traços de CAA, com até 30% de substituição do cimento por RMG quando o aditivo a base de polímeros foi utilizado e de até 20% de substituição quando o superplastificante foi o sulfonado. No estado fresco esse CAA atendeu aos requisitos da NBR 15823, se comportando como concreto adequado para utilização na maioria das aplicações correntes. No estado endurecido apresentaram resistência à compressão próximas de 35 MPa, podendo também ser utilizado na produção de pavimentos de concreto. As resistências à flexão alcançadas, em torno de 7,0 MPa, e satisfazem a NBR 15805. Para absorção os valores ficaram compreendidos entre 4,0% e 5,0%, menores que os valores encontrados na literatura, para o índice de vazios e massa específica os valores ficaram próximos de outras pesquisas, 10%. Nos ensaios de RAA as expansões alcançadas foram menores que 0,10%, sendo os resíduos classificados como inócuo pela NBR 15577-4. Com o exposto pode-se afirmar que os resíduos de marmorarias podem ter uma destinação alternativa na construção civil.

Today, a large part of the recycling facilities inert waste goes to landfill.  Landfilling with waste leads to greenhouse gasemissions and the accumulation of pollutants that are liable to leak into the surrounding environment. Water and waste expertise in Norr AB (Vakin) is responsible for all waste management in the municipality of Umeå and Vindeln and aims to climb up the waste hierarchy by finding ways to recycle landfill waste. Today 100% of the landfill fraction is deposited. The purpose of the study is to investigate alternative treatment methods of waste in a landfill fraction, to reduce the amount of landfill waste. A sorting analysis was performed at Dåva landfill and waste facility in Umeå AB (Dåva DAC) to investigate the waste content in a landfill fraction. Interview questions were sent via e-mail to communal recycling centers to compare the handling and content of the required landfill fraction. The result show that landfill fraction contained hazardous waste, glass, porcelain, concrete, plasterboard/insulation, metal, combustible/plastic, brick, stone, tile/clinker and cardboard. To recycle construction and demolition waste, the fraction must be uniform and free of extraneous material The conclusion is that concrete, tile/clinker, brick and stone are sub-fractions that have the greatest potential for recycling. With a better waste sorting at the recycling facility, the amount of landfill fraction can be reduced.

Given the increasing consumption of plastic materials their reuse becomes a very topical issue. Recycling the single-cleaned plastic waste is simple, these products can be used as raw material or additive in the manufacture of new products. The problem remains the energy, economic and environmental demands in sorting, cleaning and eventual regranulation of waste to a suitable feedstock. This problem can be solved using technology that is able to handle multiple-type waste thermoplastics in further useful products.

A questão ambiental é um tema muito discutido e pesquisado atualmente. Isto advém da constatação que os recursos naturais não são ilimitados e que o meio ambiente não tem a capacidade de absorver a quantidade atual de resíduos sem que haja um desequilíbrio ambiental. Neste contexto insere-se a indústria da construção civil, que apresenta importantes impactos ambientais em todas as etapas do seu processo produtivo, sendo um destes a geração de resíduos de construção e demolição (RCD) em centros urbanos, que resulta em efeitos deteriorantes do ambiente local onde estes são dispostos e, em virtude do seu desperdício, aumenta a extração de materiais minerais. Um dos meios de reduzir-se a quantidade de RCD disposto no meio ambiente e a extração de materiais minerais é a reciclagem do RCD e sua utilização na própria indústria que o gerou.Neste sentido, os blocos de concreto para pavimentação surgem como uma alternativa de pesquisa, já que estes têm ganhado espaço como solução para a pavimentação de áreas urbanas. Isto se deve ao aumento dos esforços de empresas e entidades representativas do setor em incentivar sua utilização e às vantagens técnicas inerentes ao sistema, como o fácil assentamento, a rápida liberação para o tráfego, a redução de iluminação pública e a permissão de acesso à rede subterrânea apenas com a retirada dos blocos, que podem ser recolocados após intervenção. Neste sentido, o presente trabalho estudou a utilização do RCD, proveniente de Porto Alegre – RS, como agregado miúdo reciclado em substituição ao agregado miúdo natural em blocos de concreto para pavimentação. Foi utilizado o intervalo de teores entre 0 % e 100%, com o objetivo de investigar-se um espectro grande de possibilidades de utilização do agregado miúdo reciclado de RCD, sendo que os ensaios escolhidos (resistência à compressão, resistência à abrasão e absorção de água) tiveram o intuito de dar subsídios ao entendimento do comportamento dos blocos produzidos perante as substituições. Após a realização dos ensaios, verificou-se que para o teor de 25% de substituição o material reciclado é passível de utilização, sendo que para os outros teores os resultados foram insatisfatórios.
Environmental issues are in the public eye and are the focus of extensive research nowadays as it becomes clear that natural resources are limited and that the large amounts of waste generated today will necessarily result in environmental imbalances. A considerable share of this waste is generated by the construction industry, whose activities hold a potential environmental impact throughout the stages of their production processes. Construction and demolition (C&D) waste generated in cities often produces detrimental effects in the sites where debris is dumped, a problem which is compounded by the fact that this waste could be used as a substitute for fresh materials that have to be extracted from mines, another activity with considerable environmental impact. A possible way to reduce the amount of C&D waste dumped in the environment and also the need for fresh mineral resources is the recycling of C&D waste by the same industry that generated it. Research on the use of concrete block paving provides an interesting alternative as this material has become more widely used in pavements of urban areas as a result of the efforts of construction companies and associations, which now endeavor to promote the use of concrete blocks. These have intrinsic technical advantages, such as their fast placement, the fast release of paved areas to traffic, the reduced need for street lighting and the ease of access to underground networks because blocks can be quickly opened up and reinstated. The present study investigated the use of C&D waste produced in Porto Alegre, RS, Brazil as a recycled substitute for conventional fine aggregate in concrete block paving. C&D waste was used as fine aggregate in concentrations ranging from 0% to 100% to provide a detailed picture of the possibilities of using recycled C&D waste as fine aggregate. The tests selected (compressive strength, abrasion resistance, water absorption) were used to provide information on the behavior of the blocks produced using different concentrations of C&D waste. These tests show that a concentration of 25% of recycled material as a substitution can be used with satisfactory results while all other concentrations yielded unsatisfactory results.

A geração de resíduos, em geral, pode trazer diversos problemas ao meio ambiente em decorrência de seu descarte inadequado, tornando necessária a busca por métodos alternativos para o manuseio, tratamento e disposição final dos mesmos. A Política Nacional Brasileira de Resíduos Sólidos de 2010 estabelece que os resíduos sólidos gerados em território brasileiro, de qualquer natureza, devem ser, nos processos geradores, reduzidos, tratados e reutilizados dentro do conceito de desenvolvimento sustentável. Estima-se que o Brasil produza, anualmente, 30.000 toneladas de isoladores elétricos de porcelana para abastecer sua rede elétrica, com uma geração de resíduos da ordem de 10% do total produzido. Diante deste cenário, a busca por alternativas para utilização de resíduos de isoladores elétricos de porcelana em novos produtos, tem despertado o interesse acadêmico e tecnológico. Neste estudo, resíduos de isoladores elétricos de porcelana (RIP) foram cominuídos em dimensões compatíveis para a aplicação em concretos permeáveis e foram caracterizados por análise física (granulométrica, índice de forma, absorção de água, massa específica). A partir da caracterização do RIP, foi proposta uma matriz experimental para a avaliação de concretos permeáveis, incorporando 50 e 100% em massa de RIP em substituição aos agregados graúdos. As propriedades de resistência mecânica sob compressão, sob tração na flexão, e o módulo de elasticidade das proporções com essas incorporações foram comparadas às de um concreto referência. Os resultados de resistência mecânica sob compressão para os concretos permeáveis propostos foram inferiores ao referência 21, e 24% respectivamente para 50 e 100% em massa de RIP, sob tração na flexão os resultados foram inferiores 38 e 46,5% respectivamente para 50 e 100% em massa de RIP, o módulo de elasticidade foi inferior ao referência 6,4% respectivamente para 50% em massa de RIP e superior 3,13% respectivamente para 100% em massa de RIP. Os resultados de resistência mecânica sob compressão, sob tração na flexão e o módulo de elasticidade para os concretos permeáveis 50 e 100% em massa de RIP encontram-se dentro dos valores relatados na literatura para concretos permeáveis. Os resultados de índice de vazios dos concretos permeáveis, referência, 50% em massa de RIP e 100% em massa de RIP ficaram numa faixa de 12,5 – 18,2% e os resultados do coeficiente de permeabilidade para os concretos permeáveis referência, 50% em massa de RIP e 100% em massa de RIP ficaram numa faixa de 0,05 a 0,2 cm∙s-1 na condição amostra seca e 0,14 a 0,15 cm∙s-1 na condição amostra saturada, contudo encontram-se dentro dos valores relatados na literatura para concretos permeáveis. Os resultados demonstram que é possível utilizar resíduos de isoladores elétricos de porcelana em substituição a agregados graúdos, permitindo incorporações de até 100% de RIP em concreto permeável.
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Companhia Paulista de Força e Luz
The generation of waste, in general, can bring many environment issues due to their improper disposal, making necessary to search for alternative methods for handling, treatment and final disposal of them. The Brazilian National Solid Waste Policy of 2010 defines that the solid waste generated in Brazilian territory, of any kind, should be, in their generators processes, reduced, treated and reused within the concept of sustainable development. It is estimated that Brazil produces annually 30,000 tons of electrical porcelain insulators to supply its power grid with a waste generation around 10% of the total production. In this scenario, the search for alternatives to the use of waste electrical porcelain insulators on new products has attracted academic and technological interest. In this study, waste electrical porcelain insulators (RIP) were comminuted in sizes compatible for use in permeable concrete. They were characterized by physical analysis (particle size distribution, shape index, water absorption and specific mass). Based on the characterization of RIP, an experimental matrix was proposed, to evaluate permeable concrete by incorporating 50 to 100%wt of RIP instead of coarse aggregate. The mechanical strength properties under compression, tension in bending and the modulus of elasticity of aforementioned proportions were compared to a reference concrete. The results of mechanical strength under compression for the proposed permeable concrete showed lower values than for the reference (values of 21 and 24% for 50 and 100 %wt of RIP, respectively). In tension in bending, the results were 38 and 46.5 % lower for 50 and 100%wt of RIP, respectively. The modulus of elasticity of the proportion 50%wt of RIP was 6.4% lower than the reference, while for the proportion 100%wt of RIP was 3.13% higher than the reference. The results of mechanical strength under compressive tensile, bending and the modulus of elasticity for the specific permeable concrete are within the reported values in the literature for this kind of material. The void index results for the permeable concrete and the reference were in a range from 12.5 to 18.2% and the results of the permeability coefficient were in a range of 0.05 to 0.2 cm s-1 in the sample dry condition and of 0.14 to 0.15 cm s-1 in the sample saturated condition, however they lie within the literature reported values for permeable concrete. The results demonstrate that it is possible to use waste electrical porcelain insulators replacing coarse aggregate, enabling the incorporation of up to 100% of RIP in permeable concrete.

In accordance with the Paris Agreement and the national goal of climate neutrality by 2045, Sweden needs to lower its greenhouse gas emissions. The second-largest source of CO2 emissions in the country comes from the production of cement, one of the main ingredients of concrete. With concrete being an ideal construction material, and Sweden needing to build more urban housing, Sweden is now in a position where they need to combine a high rate of housing construction with emission cuts to reach the climate goals. Concrete from construction and demolition waste is recyclable and can be used as an aggregate in new concrete and as an input in cement production. This is, however, currently not being done in Sweden and concrete waste is instead used for low-grade purposes such as road construction, landfill infrastructure, and backfilling.  This study, therefore, aims to identify why recycled concrete is not being used to a larger extent in Swedish housing. An interview study has been conducted with actors along the concrete value chain to find out the extent to which housing projects use recycled concrete today, as well as what challenges and possibilities there are for increased use. The results show that recycled concrete within housing projects is currently only used for backfilling. Sweden does not have big enough volumes of high-quality concrete waste for it to be commercially viable to recycle it into recycled aggregate concrete. This recycling process is both costlier and more time-consuming than using conventional methods with raw materials, something Sweden has an abundance and easy access to. There is also a reluctance within the construction industry to use new and unproven methods and materials. Improved on-site sorting of waste materials, leading to higher quality aggregates, and construction standards adapted to the use of recycled materials, are actions to be taken to allow for an increased use of recycled aggregate concrete. All interviewed actors also mentioned the potential of recycled concrete for non-load-bearing walls in housing projects.

This thesis is the story of two housing projects designed by architect Ralph Erskine. The first building, Lassaskog in Växjö built in 1954, is one of the earliest examples of industrialized concrete housing in Sweden. The other one, Kv. Ortdrivaren in Kiruna was built some eight years later following Erskine’s utopian ideas for The Arctic City. Despite their architectural and historical significance, these two buildings are threatened today: Ortdrivaren will be demolished and Lassaskog will be hastily densified.   This thesis is a reaction to these threats, and it is a call for preserving and reusing. Looking towards the near future of circularity, I want to praise for never demolishing a building again.   This leads me to the overarching question of my thesis; how could I sustainably save these two buildings?   The only solution I thought worthy of their architecture was to unite them. Rather than demolishing Ortdrivaren, I propose to deconstruct it and reuse it in Växjö. Thereon, started the project of densifying the Lassaskog estates with new student housing made of repurposed concrete elements from Kiruna.   My objective for this quirky enterprise is to find a methodology for preserving post-war housing estates and for conducting a circular architecture project.

O fresado asfáltico ou Reclaimed Asphalt Pavement (RAP), como é conhecido em língua inglesa, é um material proveniente da fresagem de revestimentos asfálticos quando da restauração de pavimentos flexíveis. Esse material é produzido em grandes quantidades nas grandes cidades, o que justifica a busca de soluções para sua destinação final. Neste trabalho foram estudados os efeitos da incorporação de RAP em Concreto Compactado com Rolo (CCR). Foram produzidas seis diferentes misturas de CCR. O CCR de referência (CCR1) foi produzido com areia industrial e serviu de parâmetro para análise das demais misturas: CCR com areia natural (CCR2), CCR com substituição de 100% da areia por RAP (CCR1AF), CCR com substituição de 100% do pedrisco por RAP (CCR1PF), CCR com substituição de 100% da brita 1 por RAP (CCR1 BF) e CCR com substituição de 50% de agregado natural por 50% da fração total do RAP (CCR1FT). Os ensaios de compressão diametral e tração na flexão mostraram que a incorporação de RAP, em qualquer fração, diminui bruscamente a resistência mecânica dos corpos de prova, em relação ao CCR de referência, sendo a queda mais acentuada no caso da resistência à compressão. O módulo de elasticidade obtido por meio da instrumentação dos corpos de prova com LVDT (Linear Variable Differential Transformer) e strain gages, assim como o módulo de elasticidade dinâmico, obtido por pulso ultrassônico, apresentaram quedas significativas, quando comparados ao CCR de referência. Os CCR com incorporação de RAP apresentaram queda nos valores de tenacidade e aumento na resistência de propagação da trinca. As observações com microscópio óptico, lupa estereoscópica e com microscópio eletrônico de varredura mostraram que a interface entre o agregado fresado e a pasta de cimento foi prejudicada pela presença do filme asfáltico nos agregados de RAP. Embora a incorporação do RAP na mistura de CCR diminua a resistência das misturas e afete todos os parâmetros mecânicos, ainda assim é um material que pode ser utilizado como base e subbase de pavimentos, pois alcançou parâmetros mecânicos que viabilizam seu uso.
Reclaimed Asphalt Pavement (RAP) is a material obtained from asphalt pavement drilled during the restoration of flexible pavements. This material is produced in large amounts in large cities, what justifies the search for alternatives for its final disposal. In this paper, we will see the effects of the addition of RAP on Roller Compacted Concrete (RCC). Six different mixes of RCC were produced. The reference RCC (RCC1) was produced with industrial sand and used to verify the effects of RAP incorporation on mixes: RCC with natural sand (RCC2), RCC with the replacement of 100% of sand with RAP (RCC1AF), RCC with the replacement of 100% of small rocks with RAP (RCC1 PF), RCC with the replacement of 100% of gravel with RAP (RCC1BF) and RCC with the replacement of 50% of natural aggregate with 50% of the total RAP (RCC1FT). The diametral compression and bending traction tests show that the addition of RAP, at any rate, abruptly decreases the strength of specimens compared with the reference RCC, and the decrease was greater for cylindrical specimens. The elastic modulus obtained through the instrumentation of specimens with LVDT (Linear Variable Differential Transformer) and strain gage, as well as those obtained by ultrasonic wave pulse showed significant decreases as compared with the reference RCC. The RCC specimens with added RAP showed a decrease in toughness values and an increase in the spreading resistance of the cracks. Observations through optical microscope, stereoscopic glass and scanning electron microscope show that the interface between the milled aggregate and the cement paste was damaged by the presence of asphalt film in RAP aggregates. Even though the addition of RAP in the RCC mixture decreases the strength of the mixtures and affects all the mechanical parameters, it can still be used as a base and subbase material for paving, since mechanical parameters have been met and make possible its use.

Orientador: João Virgilio Merighi
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: O presente trabalho visa estudar o processo de reciclagem de pavimento asfaltico com cimento Portland, atraves da analise de metodo de reciclagem, equipamentos utilizados, procedimentos empregados em campo, alem do estudo das vantagens e desvantagens do uso da reciclagem em pavimentos asfalticos. O trabalho trata ainda de uma forma detalhada o pavimento asfaltico com adicao de cimento Portland, atraves de ensaios tecnologicos simulando em laboratorio, para diferentes dosagens o comportamento mecanico em funcao do tempo do material obtido em campo.
Abstract: This work studies the process of asphalted pavement recycling with cement Portland additive through the analysis of recycling method, equipments and procedures used in the field, in addition to studying the advantages and disadvantages of the use of recycling in asphalted pavement. The work also approaches in detail the recycled asphalt pavement with Portland cement additive, through technological tests through laboratory simulation, to different dosage and the analysis of mechanical behavior through time of that material obtained in field.
Mestrado
Transportes
Mestre em Engenharia Civil

This work analysed some mechanical and durability properties of the concrete produced with fine and coarse aggregates obtained from the recycling of construction and demolition wastes (CDW) in order to evaluate the possibility to use this composite in structures. A special attention was given to the degree of porosity/strength of the coarse recycled aggregate assuming its specific gravity as one of the parameters of the study. Construction and demolition wastes were gathered from illegal deposition areas inside Maceió and were comminuted in laboratory; the grains obtained were divided into fine aggregate and coarse aggregate. One part of the coarse aggregate was mixed in with recycled concrete aggregate in order to produce a new aggregate which was less porous/stronger than the first one the amount of aggregates to be mixed were determined through a rule of mixture for the specific gravity. Concretes were produced in laboratory combining three water-cement ratio with each coarse recycled aggregate and fine recycled aggregate or river sand; reference concretes were produced with natural aggregates too. The properties of the recycled concretes were also investigated by means of a factorial design. In general, the use of coarse recycled aggregate combined with fine coarse aggregate was not good, but the less porous the coarse recycled aggregate (or the higher the specific gravity), the better the concrete properties were. Some recycled aggregate concretes reached strength values bigger than the reference concrete. Results showed that recycled concretes can be used in structures, but with some restrictions.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O trabalho analisou algumas das propriedades mecânicas e de durabilidade do concreto produzido com agregados miúdos e graúdos de RCD reciclado no intuito de avaliar a possibilidade de uso do compósito em estruturas. Uma atenção especial foi dada ao nível de porosidade/resistência do agregado graúdo reciclado. Para isso, tomouse como um dos parâmetros do estudo a sua massa específica. Os resíduos de construção e demolição foram coletados em áreas de deposição ilegal dentro da cidade de Maceió e foram cominuídos em laboratório, sendo o material granular obtido separado em duas frações: agregado miúdo e agregado graúdo. Uma parte do agregado graúdo foi misturada com agregado graúdo de concreto reciclado de forma a produzir um novo agregado reciclado menos poroso/mais resistente as quantidades dos dois agregados a serem misturadas foram determinadas com o auxílio de uma regra de mistura para a massa específica. Traços foram produzidos em laboratório com três níveis de relação a/c combinando-se cada agregado graúdo reciclado com o agregado miúdo reciclado ou com uma areia natural. Ao mesmo tempo, concretos de referência foram produzidos com agregados naturais. As propriedades dos concretos reciclados foram analisadas também por meio de um experimento fatorial. Em termos gerais, o uso combinado de agregado graúdo reciclado com agregado miúdo reciclado não foi vantajoso, mas as propriedades dos concretos foram tanto melhores quanto menor foi a porosidade (ou, maior a massa específica) dos agregados graúdos reciclados. Alguns concretos reciclados chegaram a apresentar resistências mecânicas maiores que as de seus respectivos concretos de referência. Os resultados encontrados permitem afirmar que concretos reciclados podem ser usados em estruturas, mas com restrições.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico
FINEP - Financiadora de Estudos e Projetos
A construção civil é um dos setores que mais consome recursos naturais não renováveis, além de ser um dos principais geradores de resíduos sólidos urbanos (RSU). Dentre os diversos recursos naturais extraídos da natureza, os agregados utilizados na construção civil são os insumos minerais mais consumidos no mundo. Com a crescente restrição da extração de areias dos rios e a escassez de areias naturais é essencial que o setor da construção venha a adotar uma postura ambiental e sustentável, através de desenvolvimentos tecnológicos de processos de reciclagem de resíduos. Uma das alternativas para a construção civil, tanto do ponto de vista econômico quanto ambiental, no abastecimento de areia para a construção é a substituição das areias extraídas dos rios (areia natural) por resíduos de concreto, para a produção de argamassas. Este estudo tem como objetivo principal avaliar o comportamento de argamassas de revestimento com incorporação de agregado miúdo reciclado de concreto (AMRC), em substituição à areia natural extraída de rio (AN). Os AMRC foram obtidos a partir de resíduos de dois tipos de concreto empregados na pré-fabricação: de concreto submetido à cura térmica à vapor (ARCT) e outro de concreto submetido à cura convencional (ARCC). As argamassas foram confeccionadas com cimento CP II Z– 32 e cal CH-I, empregando-se traço em volume 1:1:6 com índice de consistência fixado em 260 ± 5 mm, para as três misturas de argamassas. O estudo foi desenvolvido em duas etapas. Na primeira etapa foram analisadas a caracterização morfológica e a distribuição granulométrica das areias. Na etapa seguinte analisou-se o comportamento e características das argamassas no estado fresco e no estado endurecido. A análise das argamassas no estado fresco contemplou dados de índice de consistência, penetração de cone, squeeze flow, retenção de água, densidade de massa e teor de ar incorporado. No estado endurecido as propriedades estudadas foram densidade de massa, resistência à compressão, resistência à tração na flexão, absorção de água por capilaridade e coeficiente de capilaridade, absorção de água, índices de vazios, massa específica, módulo de elasticidade dinâmico e porosidade por intrusão de mercúrio. Verificaram-se diferenças significativas no comportamento das argamassas confeccionadas com os dois agregados reciclados. No estado fresco foi observado perda de trabalhabilidade; perda de densidade de massa; aumento de ar incorporado, com perdas mais expressivas para a mistura com ARCC. No estado endurecido observou-se redução da resistência à compressão e da resistência à tração na flexão para as argamassas com ARCC. Os dados apontaram ainda diminuição de absorção de água por capilaridade; aumento da absorção de água por imersão; aumento do índice de vazios; aumento da massa específica e redução do módulo de elasticidade dinâmico para ambas as argamassas com agregados reciclados.
The construction industry is one of the sectors that consume non-renewable natural resources, besides being one of the main generators of municipal solid waste. Among the various natural resources extracted from nature, the aggregates used in construction are the most consumed mineral inputs in the world. With the increasing restriction of sand extraction from rivers and the scarcity of natural sands it is essential that the construction industry adopt an environmental and sustainable development, through technological processes to recycle waste. One of the alternatives to the construction industry, from an economical and environmental point of view, the supply of sand for construction is the replacement of sand extracted from rivers (natural sand) for concrete waste, for the production of mortars. This study aims at evaluate the behavior of rendering mortar with incorporation of recycled aggregate concrete, replacing the natural sand. The morphological characteristics and composition of two aggregates made from concrete were analysed: one from concrete subjected to thermal curing and other to conventional curing, compared with a river sand. Characterization tests were performed on fresh mortar (consistency index, cone penetration, squeeze flow, water retention, density and air content) and hardened mortar (density, compressive strength, flexural strength, capillarity water absorption and capillarity coefficient, water absorption, density, dynamic modulus of elasticity and mercury intrusion porosimetry). For this experiment were followed the requirements of NBR 13281 (ABNT, 2005) and used Brazilian CP II Z-32 cement and CH-I lime. A proportion of 1:1:6 (cement, lime and sand) by volume, with index consistency set at (260 ± 5) mm was adopted for the three mixtures of mortars. There were significant differences in the behavior of the two mortars made with recycled aggregates, such as: loss of workability; loss of density; increased air content (especially mixing with ARCC), in fresh stage. Reduction of compressive strength and reduced flexural strength (except in the mixture with ARCT), reduction of water absorption by capillarity, increased water absorption by immersion, an increase in the index of emptiness, increased density and reduced dynamic modulus of elasticity, in the hardened mortar.

Orientador: Luísa Andréia Gachet Barbosa
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
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Resumo: O reaproveitamento de resíduos na construção civil tem sido uma alternativa viável para diminuir o consumo de materiais naturais e a disposição inadequada dos resíduos no meio ambiente. Neste trabalho avaliou-se o reaproveitamento de resíduo de borracha de pneus, proveniente do processo de recauchutagem, em substituição parcial do agregado miúdo natural, para a produção de pisos táteis intertravados de concreto. O piso tátil de concreto é uma peça utilizada na pavimentação, que permite a percepção do ambiente ou rotas acessíveis, proporcionando mais segurança e autonomia para as pessoas com deficiência visual. A substituição foi feita em relação à massa da areia nas proporções de 10%, 20%, 30%, 40% e 50%. As seguintes propriedades do concreto foram investigadas: consistência no estado fresco, resistência à compressão, resistência à tração na flexão, absorção de água, índice de vazios, massa específica do concreto endurecido, resistência à abrasão, resistência ao impacto e análise de microestrutura. Embora a grande limitação do uso da borracha de pneus como agregado no concreto seja a redução das resistências mecânicas, os traços com até 50% de substituição atingiram ótimos valores de resistência à compressão e resistência à tração na flexão e apresentaram melhores resultados de resistência à abrasão. A utilização do resíduo de borracha de pneus, em substituição parcial da areia natural no concreto para a produção de piso tátil, além de contribuir com a sustentabilidade na construção civil, por meio da economia de extração de matérias-primas e redução do descarte e acúmulo inadequado de pneus inservíveis, proporcionou melhorias a algumas propriedades importantes para a eficiência e qualidade do piso tátil de concreto
Abstract: The reuse of waste in construction has been a viable alternative to reduce the consumption of natural materials and the improper disposal of waste on the environment. In this work recycled tire rubber (crumb rubber) was used as aggregate in concrete to produce tactile paving block. The concrete tactile paving block allows perception of the place or accessible routes, providing more security and independence for people with visual disabilities. The crumb rubber was used to replace sand by mass at the level of 10%, 20%, 30%, 40% and 50%. The concrete characterization was performed by testing its consistency, compressive strength, flexural strength, water absorption, porosity, density, abrasion resistance, impact resistance and microstructure analysis. Although the major limitation using the crumb rubber as aggregate in the concrete is to reduce the mechanical strength, the mixtures with up to 50% of substitution reached optimal values ??of compressive strength and flexural strength and showed a better abrasion resistance. The use of crumb rubber in partial replacement of natural sand in concrete to produce tactile paving block, proved to be a viable alternative. Besides contributing to construction sustainability, minimizing the extraction of raw materials, and reducing improper disposal and accumulation of scrap tires, provided improvements to some important properties that assure the efficiency and quality of the concrete tactile paving block
Mestrado
Tecnologia e Inovação
Mestra em Tecnologia

L’objet de cette thèse porte sur le développement de technologies efficaces pour le recyclage du béton. Le béton est le plus utilisé des matériaux conçus par l’homme, et par voie de conséquence, sa fabrication consomme plus de ressources naturelles que n’importe quelle autre industrie. Le béton est responsable de 7% des émissions anthropiques de CO2, la moitie provenant de la décarbonatation du calcaire. Compte-tenu des quantités de matières utilisées et de déchets produits, le recyclage du béton est un enjeu environnemental majeur, et une priorité grandissante. Le principal défi au développement et à la mise en oeuvre d’un procède de recyclage du béton concerne la difficulté à séparer ses constituants, les graviers et la pâte de ciment. Le chauffage microonde est un candidat idéal pour parvenir à ce résultat, de par sa capacité à chauffer sélectivement les différentes phases d’un matériau multiphasique, induisant ainsi des fractures aux interfaces entre phases et conduisant à leur libération. Les effets du chauffage microonde sur le béton ont donc été étudies dans cette thèse avec l’objectif de conclure quant au bien-fondé de développer un procède de recyclage qui intègre les microondes. Les effets ont été mesures par des analyses classiques d’échelle macroscopique qui ont mises en évidence une corrélation significative entre le chauffage, l’augmentation de porosité et la diminution des propriétés mécaniques du béton. Pour mieux comprendre les changements mesures à une échelle macroscopique, une technique d’analyse locale d’images de la texture du béton, base sur la microscopie électronique, a été développée. L’analyse locale des changes induits par le chauffage du béton a révélé la présence d’une porosité de fractures, qui a permis d’expliquer les changements observes des propriétés du béton les plus pertinentes vis-à-vis du recyclage. L’analyse de la texture du béton soumis au chauffage par microondes a mis en évidence la formation de deux réseaux de fractures dans la pâte de ciment, dont le développement est dicte par les conditions du chauffage microonde. Les propriétés texturales de ces réseaux de fractures ont été corrélées directement aux variations des propriétés macroscopiques du béton, ainsi qu’à la libération des agrégats. L’analyse texturale a montré que la croissance de la fracture à l’interface entre les agrégats et la pâte de ciment survient durant les premiers instants du chauffage, et que la libération des agrégats dans le béton, appelée libération texturale, est significativement plus grande que la libération mesurée après fracture du béton par impact. Cette observation a démontré l’importance de choisir un mode de fragmentation capable de tirer parti de la fracture sélective des interfaces agrégat-ciment. De plus, le travail réalise a établi qu’il existe des relations de causalité entre les variations de la porosité de fractures présente dans le béton et les propriétés du béton les plus significatives pour son recyclage, revelant ainsi la possibilite de concevoir un procede de valorisation des dechets de béton en manipulant la texture du béton. En etablissant que le chauffage microonde permet de modifier la porosite de fractures du béton, ce travail conclut que le chauffage du béton par microondes est une technologie prometteuse pour concevoir un procede de recyclage du béton. Au-dela du seul objectif du recyclage du béton, la demonstration de l’existence de relations de causalite entre les proprietes de texture du béton et les criteres de performance associes a sa fragmentation ouvre des perspectives nouvelles pour analyser et concevoir des procedes de broyage des minerais
This thesis is concerned with the development of efficient concrete recycling technology. Concrete is the most used manufactured material on the planet and as a consequence uses more natural resources than any other industry and is responsible for 7% of the world’s carbon dioxide production, 50% of that originating from the decarbonisation of limestone. Given the magnitude of materials used and the waste produced the recycling of concrete would be a major environmental boon and should be made a priority. The main obstacle to the development and implementation of a concrete recycling process is the necessity of separating concrete components, aggregate and cement paste before recycling. Microwave heating stands as an ideal candidate due to its capacity to selectively heat different phases in a multiphase material, thus producing phase boundary fracture and increasing the liberation of the component phases. The effects of microwave heating on concrete samples were investigated with the intent of concluding on the possibility of deriving a microwave-based recycling process for concrete. The effects were measured using standard macroscopic techniques and found a strong correlation between heating, increased porosity and decreased mechanical strength for concrete. In order to better understand the changes measured at the macroscopic scale, a dedicated image analysis technique was developed using electron microscopy to investigate local microscopic changes in concrete texture. Local investigation of the changes of heat treated concrete identified the presence of fracture porosity, which has significant explanatory power for observed changes in concrete properties most relevant to recycling. Textural analysis of concrete subjected to microwave heating showed the growth of two different networks of fractures throughout the cement paste matrix, whose development is associated with the microwave settings. These textural fracture properties correspond directly to the observed changes in mechanical properties as well as the observed liberation of aggregate particles. Textural analysis shows that phase boundary fracture growth occurs rapidly in the early stages of microwave treatment and that the absolute value of textural liberation is significantly higher than that of physical liberation. This highlights the importance of choosing an appropriate comminution method to make efficient use of phase boundary fracture. Moreover, the work established causal relationships between variations in fracture porosity and changes in properties of concrete most relevant to recycling, revealing the possibility of designing a concrete waste beneficiation process through manipulating concrete texture. Since microwave heating was found to be able to manipulate the form taken by the fracture porosity, this work concludes that microwave heating of concrete is a promising technology for designing a concrete recycling scheme. Moreover, through demonstration of causal links between textural properties and processing performance criteria, this work opens the possibility of an alternative approach for analysing and designing comminution process for minerals

This diploma thesis deals with the issue of using fine powder of concrete recyclate. In this thesis, the theoretical expectations of milling are summarized as well as high energy milling. Afterwards professional articles, in which fine powder of concrete recyclate is successfully activated, are described and commented on. In the experimental part, there are 11 recipes of cement mortar and 3 recipes of concrete mixed. The benefit of using fine powder of concrete recyclate as a possible substitute for part of the cement is evaluated.

Orientador: Vitor Antonio Ducatti
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: O principal objetivo desta dissertação foi a determinação das principais propriedades mecânicas de um compósito à base de cimento Portland CP-V-ARI (alta resistência inicial) tendo como agregado os grãos reciclados aglutinados de polipropileno (GRAP). A escolha do plástico se deve ao fato de que é um dos principais materiais utilizados pela indústria em geral sendo descartado em média na proporção de 7% do peso e 25% do volume do lixo urbano metropolitano e índice de reciclagem de 17,5%. No caso específico do polipropileno a proposta de seu uso deveu-se ao fato dele ser um dos três plásticos mais consumidos e descartados no Brasil, tornando-se oportuno o desenvolvimento de alternativas para a reciclagem deste material como material para a construção civil como agregado para o concreto. Neste estudo, foram realizados ensaios com base nas normas da ABNT ¿ Associação Brasileira de Normas Técnicas, para a caracterização do concreto no estado endurecido, principalmente para a determinação das resistências à compressão axial e diametral, resistência à tração na flexão e módulo de elasticidade secante. Os resultados obtidos em ensaios com misturas com e sem agregados minerais (substituição) foram satisfatórios permitindo o desenvolvimento de vários concretos com resistência à compressão axial (fcj) adequado para a produção de elementos pré-fabricados, concretos porosos adequados para drenagens e enchimento de lajes, painéis, blocos de concreto e grãos de polipropileno mineralizados com a pasta de cimento, dentre outras aplicações. Houve uma redução superior a 30% do peso final do concreto por meio da redução da massa específica. O novo concreto também se mostrou extremamente dúctil, adequado para especificações de absorção de impactos. Através dos resultados desta pesquisa pôde-se concluir que é perfeitamente viável o uso do concreto com grãos de polipropileno em substituição aos agregados minerais na construção civil
Abstract: The main objective of this dissertation was the determination of the main mechanical properties of a composite based on Portland cement CP-V-ARI (high initial resistance) tends as aggregate the grains recycled agglutinated of polypropylene (GRAP). The choice of the plastic is due to the fact that it is one of the main materials used by the industry in general being discarded on average in the proportion of 7% of the weight and 25% of the volume of the metropolitan urban garbage and index of recycling of 17,5%. In the specific case of the polypropylene the proposal of his use was due to his fact to be one of the three plastics more consumed and discarded in Brazil and that indicators reveal the need to develop alternatives for the recycling of this material in the engineering and in the building site as an aggregate for the concrete seeking the partial or total substitution of minerals aggregates. In this study, rehearsals were accomplished with base in the norms of ABNT - Brazilian Association of Technical Norms, for the characterization of the concrete in the hardened state, mainly for the determination of the resistances to the axial and diametrical compression, resistance to the traction in the flexing and module of drying elasticity. The results obtained in rehearsals with mixtures with and without aggregates minerals (substitution) they were satisfactory allowing the development of several concretes with resistance to the axial compression (fcj), through appropriate mixtures to the production of prefabricated elements, an appropriate porous concrete for drainages and stuffing of flagstones and polypropylene grains mineralized with the cement paste, among other applications. There was a superior reduction to 30% of the final weight of the concrete through the reduction of the specific mass. The new concrete was also shown extremely ductile, appropriate for specifications of absorption of impacts. Through the results of this research it could be concluded that it is perfectly viable the use of the concrete with polypropylene grains in substitution to the mineral aggregates in the building site
Mestrado
Edificações
Mestre em Engenharia Civil

O baixo consumo de agregados de Resíduos de Construção e Demolição (RCD) deve-se, atualmente, à sua variabilidade natural e à falta de controle de sua qualidade, que limitam sua utilização em aplicações de maiores demandas, tais como concretos. Uma maneira usual de controle de agregados para concretos se dá por meio da determinação de sua porosidade, expressa pelas propriedades físicas de massa específica e absorção. O método utilizado para medir estas propriedades é a NM 53, norma derivada da ASTM C127. Porém, foi originalmente concebida para caracterizar agregados naturais, não sendo adequada sobre agregados de RCD reciclados. Nesse sentido, o objetivo deste trabalho é estabelecer um método rápido e preciso para controle de qualidade e triagem de agregados reciclados em usinas de reciclagem, o que poderia ampliar as possibilidades de campos para sua utilização. Para isso, foram estudados comparativamente três métodos distintos - NM 53, massa submersa no tempo e secagem - para determinação das propriedades físicas absorção e massa específica aparente (MEA) dos agregados reciclados. Os planejamentos experimentais basearamse em modelos estatísticos do tipo fatorial completo, que permitem melhorias do processo selecionado, de acordo com necessidades estabelecidas, através de análises de variáveis de possível significância às respostas. A adequação da NM 53 para utilização sobre agregados reciclados depende de: 1) aumento da saturação dos poros das amostras; 2) diminuição da perda de massa durante os ensaios; e 3) aumento da rapidez das determinações. Após a execução dos planejamentos experimentais, pôde-se propor um novo método para determinação da absorção e MEA de agregados graúdos de RCD reciclados. Tal método aumentou estatisticamente os valores de absorção medidos (aumento da saturação de poros), diminuiu a perda de massa das amostras durante a execução dos ensaios e ainda reduziu o tempo de caracterização de 48 horas (mínimo dispensado pela NM 53) para aproximadamente 4 horas. O método utiliza equipamentos simples e de baixo custo, possuindo potencial real para ser implantado para controle de qualidade de agregados de RCD reciclados em usinas de reciclagem.
The low consumption of Construction and Demolition Waste (CDW) recycled aggregates happens, nowadays, because its natural variability and quality control absence that limit its use in applications with larger demands, such as concretes. One way of concrete aggregates control is done by determining its porosity, express by physical properties absorption and relative density. The method that measures its properties is the NM 53, standard derived from ASTM C127. But this standard was conceived to characterize natural aggregates, and is not appropriate on CDW recycled aggregates. In this way, the purpose of this work is to establish a quick and accurate method for quality control and selection of recycled aggregates in recycling plants, which could increase the possibilities of fields for its use. Thus, this work comparatively studied three distinct methods - NM 53, submerged mass in time and drying - for determining physical properties absorption and relative density of recycled aggregates. The experimental plannings were based on statistical models type Design of Experiments (DOE) that allow improvement on a selected process, in accordance with established needs, through analysis of possible significant variables for results. The adaption of NM 53 to recycled aggregates characterization depends on: 1) increase of sample pores saturation; 2) decrease of mass loss during the tests; and 3) increase of determination speed. After execution of experimental plannings, a new method for determining CDW coarse recycled aggregates physical properties could be proposed. This method statistically increased the measured absorption values (pores saturation increase), decreased mass loss during tests executions and reduced the characterization time from 48 hours (minimum used by NM 53) to approximately 4 hours. The method uses simple and low costs equipment, having real potential to be implemented for quality control of CDW recycled aggregates on recycling plants.

Modernization has brought about steady increase in the consumption of goods and services by human societies across the globe, which mostly driven by both population growth and the change of individual living standards. This, of course, leads to an ever-increasing waste production that ends up in landfills and very often as a source of pollution on natural ecosystems, especially in the low and middle-income countries where waste management is almost inexistent. The management of waste streams is a huge challenge for developed countries as well, where societal and environmental impacts are visible despite massive investments in waste management. One of the most problematic waste materials is plastic, which can remain in nature for over 100 years without degradation, leading to serious environmental concerns. As one of the most significant innovations of the 20th century, plastic is a widely used and cost-effective material for many applications. After their useful lifetimes, their management is problematic. Thus, robust and innovative approaches of managing such waste material are needed in order to mitigate the problem. One of the innovative approaches of tackling the menace cause by plastic waste is through its incorporation into the construction materials. This thesis seeks to address this problem by exploring the use of melted plastic wastes (High Density Poly Ethylene, HDPE and Low Density Poly Ethylene, LDPE) as binder in developing new construction materials (mortar with melted plastic as the only binder, MPB and Plastic Waste Crete, PWC) as an alternative to partially replace traditional concrete and mortar, or finding other engineering uses for this type of waste. Worldwide, about 190 m3 of concrete is poured every second, which translates to 6 billion m3 per year and making it, one of the most widely used manufactured materials. However, the production of concrete requires water and cement. Cement is expensive, and its production contributes to the emission of environmentally polluting gases. Replacing this binding element with recycled plastic derivatives would have significant economic and environmental benefits. In addition to the elimination of cement cost, this will result in water savings, which is especially important for areas without fresh water scarcity. Some researchers have used plastics in concrete and mortars as additives and/or replacement for fine and coarse aggregates. In addition, different types of plastics have been used in bitumen as an additive to reduce construction cost and improve sustainability by adding value to wastes materials. However, there is paucity of technical information about the use of the melted HDPE and LDPE plastic wastes as the only binding phase in concrete- or mortar-like materials. Moreover, many parameters such as preparation conditions, field variables, constituent elements, and final applications have impacts on the performance of construction materials Thus, the key objective of this PhD research is to develop the mortar with plastic binder (MPB) and PlasticWasteCrete (PWC) by using molten HDPE and LDPE plastic wastes as the only binder as well as to investigate the engineering properties of these new types of construction materials. The plastic contents of 45%, 50%, 60% and 65% and HDPE to LDPE ratios of 40/60, 50/50, and 60/40 were selected for the experimental tests. Clean river sand was used as the only aggregate for the MPB, while both sand and gravel were used for the PWC. Various tests were then performed on prepared MPB and PWC samples at different curing times from early to advanced ages to assess their engineering properties. These tests were conducted in accordance with the ASTM standards to evaluate the mechanical properties (compressive strength and splitting tensile strength), permeability and density of the MPB and PWC materials. Additional tests were carried out to analyze the products at the microstructural level (optical microscope, SEM, MIP and thermogravimetric analysis) to gain an insight into the microstructural properties of the developed materials and how that affect their engineering properties. The compressive strength tests revealed the optimal plastic content for the MPB and PWC with the best strength performance. The average compressive strength values for various optimal formulations after 28 days were found to be in the range of 9 to 18 MPa. The splitting tensile strength for the new materials from 1 to 28 days of curing time, were found to be between 1 and 5 MPa. The average hardened density of the MPB and PWC is about 2 g/cm3, which makes them lightweight material according to RILEM classification. In addition, various absorption tests (capillary and immersion) were performed on different MPB and PWC samples, and the obtained results showed that they are porous materials having lower rate of absorption than the traditional cementitious materials (mortar, concrete). This observation was supported by the results from both MIP and SEM analyses. Finally, thermogravimetric analysis provided interesting details on the thermal decomposition of the new materials, with significant changes or mass loss for these products being observed only at temperatures higher than 300°C. The findings from this study suggest MPB and PWC made with melted plastic waste as the only binder have a promising potentials for use in construction. The research conducted in this PhD study offers a good understanding of the engineering properties of the materials as well as the optimal formulations that yield best performance in terms of strength and durability. In summary, it provides useful technical information and tools on the MPB and PWC that will contribute in setting guidelines on the optimal applications of these products in the field of construction in order to have safe, durable and cost-effective structures. Résumé Avec la modernisation de nos sociétés, les habitudes ont considérablement changé, ainsi, on observe une forte consommation des biens et services, due à l’augmentation de la population et l’amélioration de leurs conditions de vie. Ce qui conduit à une augmentation considérable des quantités des déchets qui terminent leurs cycles au niveau des décharges ou dans les océans/fleuves devenant ainsi une source de source de pollution des écosystèmes naturels, surtout dans les pays à revenu faible et intermédiaire avec des systèmes défaillants ou moins performants de gestion des déchets. La gestion des flux de déchets est aussi un défi pour certains pays développés, où les impacts sociaux et environnementaux sont visibles en dépit des investissements massifs dans ce secteur. Parmi ces déchets, nous avons les plastiques, l’une des innovations du 20e siècle avec des qualités versatiles et coût faible, se trouve partout dans nos vies quotidiennes. Après leur utilisation, les plastiques deviennent des déchets qui peuvent rester dans la nature plus de 100 ans sans aucune dégradation, avec des conséquences néfastes sur l’Homme et l’environnement. Ainsi, une approche robuste et innovante de gestion de ces déchets est nécessaire afin d'atténuer leurs impacts. L'une des approches innovantes pour réduire l’impact causé par les déchets plastiques consiste à les incorporer dans les matériaux de construction. Ainsi, le problème est abordé dans cette thèse en développant des technologies permettant de recycler les plastiques fondus comme liant dans les nouveaux matériaux de construction (MPB et PWC), afin d’offrir une alternative pour remplacer partiellement le béton / mortier traditionnel. Le béton est l’un des matériaux les plus utilisés au monde, avec environ 190 m3 coulés chaque seconde, correspondant à 6 milliards de m3 par an. Cependant, la production de béton nécessite de l'eau et du ciment. Le ciment coûte cher et sa production contribue à l'émission de gaz polluants l'environnement. Le remplacement d'une partie du béton traditionnel par un matériau à base des déchets plastique aura des avantages économiques, sociaux et environnementaux importants. Allant dans ce sens, certains chercheurs ont utilisé les plastiques dans le béton et le mortier comme additifs et / ou substituts des matériaux granulaires tels que le sable et le gravier. Aussi, différents types de plastiques ont été utilisé dans le bitume comme additif pour réduire les coûts de construction et améliorer la durabilité, ainsi contribuer à donner de la valeur aux déchets. Cependant, jusqu'à présent, il existe peu d’informations techniques sur l'utilisation de déchets plastiques (HDPE et LDPE) fondus comme seuls liants pour développer de nouveaux types de matériaux de construction. En plus, plusieurs facteurs (les conditions de préparation, les éléments constitutifs, les applications finales, etc.) ont un impact sur les caractéristiques des matériaux de construction. Ainsi, l'objectif de cette recherche doctorale est de développer des nouveaux matériaux de construction (MPB et PWC) en utilisant les déchets plastiques fondus (HDPE et LDPE) comme seul liant, puis déterminer les propriétés caractéristiques de ces matériaux afin de trouver la formulation optimale conduisant à la meilleure résistance. En plus de l'élimination du coût du ciment, cette technologie permet aussi de faire des économies d'eau, bénéfique surtout pour les zones avec des difficultés d'accès à l’eau potable. Cela contribuera à la réduction des coûts de la construction en utilisant les produits innovants comme alternative au béton / mortier conventionnel. Un vaste programme expérimental, comprenant des tests à petite et grande échelle, a été développé afin d'atteindre les objectifs de cette étude de doctorat. La campagne expérimentale a comporté différentes étapes comprenant la sélection des matériaux, la détermination de la formulation optimale et les conditions appropriées pour la préparation des matériaux susmentionnés. Par la suite, pour une meilleure compréhension du comportement technique et des propriétés du produit final, divers tests ont été effectué sur les matériaux préparés à différents temps de durcissement. Ces tests ont été menés conformément aux normes ASTM pour évaluer les propriétés mécaniques (résistance à la compression et à la traction), la perméabilité et la densité des nouveaux matériaux. Les expériences ont été approfondies en analysant les produits au niveau microstructural (microscope optique, SEM, MIP et analyse thermique) pour avoir un aperçu des propriétés microstructurales des matériaux développés et essayer de comprendre les relations avec leur comportement mécanique. Les essais de compression ont permis de trouver la teneur en plastique optimale pour les matériaux (MPB et PWC) avec les meilleures valeurs de résistance. Les résistances moyennes à la compression à 28 jours pour diverses formulations étaient comprises entre 9 et 18 MPa. La résistance à la traction par fendage des nouveaux matériaux entre 1 et 28 jours se situait entre 1 et 5 MPa. La densité moyenne du béton et mortier écologique est proche de 2 g / cm3, ils peuvent donc être considérés comme des matériaux légers selon la classification RILEM. De plus, divers tests d'absorption (capillaire et par immersion) ont été réalisé sur différents échantillons de MPB et PWC, les résultats obtenus ont montré qu'il s'agit de matériaux poreux ayant un taux d'absorption plus faible que les matériaux traditionnels contenant du ciment. Plusieurs analyses microstructurales ont été réalisées sur différents échantillons des nouveaux produits (MPB et PWC) et les matériaux cimentaires traditionnels ont été utilisés pour renforcer notre compréhension. Enfin, l'analyse thermique a fourni des détails intéressants sur la décomposition thermique de ces nouveaux matériaux ; des changements significatifs avec une perte de masse considérable ont été observés seulement pour des températures supérieures à 300 ° C. Les résultats de ces essais permettent d'acquérir une bonne compréhension des propriétés techniques des nouveaux matériaux (MPB et PWC) ainsi que de déterminer les teneurs optimales en plastique conduisant aux meilleures performances en termes de résistance et de durabilité. Ainsi, les recherches menées dans cette étude de doctorat fournissent des informations techniques et des outils utiles sur le MPB et le PWC; et contribueront à installer des bases pour guider les applications optimales de ces nouveaux produits dans le domaine de la construction afin d'avoir des structures sûres, durables et rentables.

Betong är idag och har länge varit det allra vanligaste byggnadsmaterial i Sverige. Det är ett robust och mångsidigt byggnadsmaterial med flera fördelar. Detta arbete är en experimentell studie av betongavfall från Hedareds sand & betong för betongprogrammet RE: Concrete och Högskolan i Borås. Betongavfallet krossas till ny ballast och därefter siktas och gjuts till ny betong enligt olika betongrecept. Försöken sker i betonglabbet i Högskolan i Borås för att krossa och tillverka betong. Grundreceptet har tillhandhållits av Hedareds sand & betong. Syftet med arbetet har varit att undersöka möjligheterna för att kunna använda återvunnen betong i nya bärande konstruktioner. Målet var att bevisa att det var tekniskt möjligt att åstadkomma en 100 % ersättning av ballast med återvunnen betong och få fram ny betong som passar den bärande stommen i en byggnad. Olika egenskaper undersöktes så som tryckhållfasthet för den nya betongen och partikelfördelning samt vattenabsorption för ballasten med målet att uppnå likvärdigt resultat som för referensbetongen. Resultatet visar att det är möjligt att kunna återvinna betong till 100 %. Arbetbarheten är bra i flertal försök men bör förbättras för att uppnå likvärdig arbetbarhet som referensbetongens. Referensbetongens tryckhållfasthet är 59 MPa och bästa tryckhållfasthet som erhållits för återvunnen betong är 57,2 MPa. Detta tyder på ett positivt resultat och den återvunna betongen i denna studie kan ersätta naturgrusballast i en bärande konstruktion till 100 %.
Concrete is and has been for a long time the most common building material in Sweden. It is a robust and multipurpose building material with several advantages. This report is about an experimental study of concrete waste from Hedareds sand & betong. The concrete waste is crushed to a new aggregate and then sifted and casted into new concrete. The study was conducted in the Concrete Laboratory at University of Borås for crushing and casting of concrete. Recipes are supplied by Hedareds sand & betong as a starting point, which is later modified gradually to achieve better results. The purpose of this study is to investigate the possibilities for using recycled concrete in new constructions. It is also examined if the recycled concrete is technically sustainable and if the workability is good enough for using in load bearing structures. Different properties are studied such as compressive strength, particle distribution, water absorption and workability to achieve equivalent results as the reference concrete. The result obtained in this study shows that it is possible to recycle concrete by replacing aggregates to 100 % in new concrete. Workability is good in several tests, but it should be improved to achieve the same workability as the reference concrete. The reference concrete's compressive strength is 59 MPa and the best compressive strength obtained for recycled concrete is 57.2 MPa. This indicates positive results and the recycled concrete in this study can replace ordinary concrete in a load bearing construction.

A practicum report for the degree of Master of Environmental Science, Institute of Environmental Sciences, Miami University, 2007.
Title from first page of PDF document. Includes bibliographical references (p. 63-73).

A realização de uma eficiente gestão e gerenciamento dos resíduos sólidos urbanos (RSU) é um desafio ao meio técnico-acadêmico e administrativo das grandes cidades. Os resíduos de construção e demolição (RCD) consistem em uma importante parcela dos RSU, em função do volume dos mesmos se é gerado e dos danos que estes podem trazer ao meio-ambiente. A reciclagem dos RCD tem sido uma solução adotada no gerenciamento dos mesmos, sendo em sua grande maioria voltada para a produção de agregados reciclados, em função do grande volume de agregados que são usados pela indústria da construção civil. Entretanto, a grande variabilidade apresentada na composição desses agregados é uma das barreiras na difusão do uso dos mesmos como matéria-prima alternativa na confecção de concretos. Com o intuito de contribuir nesta área de conhecimento, através dos resultados obtidos em um programa experimental baseado em um projeto fatorial fracionado composto de segunda ordem, que contempla a produção de concretos com os três principais componentes do RCD (concreto, argamassa e cerâmica vermelha), modelou-se o comportamento da resistência à compressão (fc), do módulo de deformação (Ec), da retração por secagem (\'épsilon\') e do volume de poros permeáveis (VPP) dos concretos produzidos, ao se variar o teor de substituição dos agregados naturais pelos reciclados e a relação água/cimento. Os resultados indicam que com exceção da resistência à compressão para o concreto confeccionado com o agregado miúdo reciclado de cerâmica vermelha, a substituição dos agregados naturais pelos reciclados minora o desempenho dos concretos para todas as propriedades estudadas. Observou-se também que a substituição do agregado miúdo natural pelos miúdos reciclados influencia mais no desempenho dos concretos, sobre as propriedades estudadas, que a substituição dos agregados graúdos naturais pelos graúdos reciclados. Ao se validar os modelos propostos para a fc e para o Ec, utilizando dados provenientes de outros autores, observou-se que tais modelos descrevem muito bem o comportamento das propriedades, embora não tenham produzido valores semelhantes aos publicados originalmente. Simulou-se também, utilizando os modelos propostos, o uso dos agregados reciclados de RCD de algumas cidades brasileiras na fabricação de concretos, sendo que, de uma maneira geral, percebeu-se uma grande viabilidade no uso dos mesmos, uma vez que os concretos simulados ainda atingiram consideráveis fc e Ec, principalmente quando se utilizou o agregado miúdo. Classificaram-se também os concretos quanto à durabilidade baseando-se nos acréscimos do VPP para com o concreto de referência de relação a/c=0,46, sendo que a classificação encontrada sugere que os concretos com elevados teores de substituição não possuem um bom desempenho com relação à sua durabilidade, sendo a substituição de pequenos teores dos agregados miúdos mais recomendada. De uma maneira geral, pode-se concluir que é possível utilizar agregados reciclados, considerando-se as variabilidades dos mesmos, na produção de concretos com desempenho mecânico e durabilidade satisfatórios, dentro das condições estudadas.
An efficient solid waste management is a challenge to the technician-academic and administrative sectors of great cities. Construction and demolition (C&D) wastes are an important portion of solid wastes, due to their great volume and to the damages that they can bring to the environment. Recycle C&D wastes has been adopted as a management solution and the production of recycled aggregates has been a practice quite used, in function of the great volume of aggregates that have been used by the construction industry. However, the great variability presented in the composition of those aggregates is one barrier to diffuse the use of them as an alternative material to make concrete. Intending to contribute in this knowledge area, an experimental program based on a fractional factorial project was done. It consisted in produce concretes with the three main components of C&D waste (concrete, mortar and red ceramic) as recycled aggregates, varying the percentage of substitution of natural aggregates by recycled aggregates and the water/cement ratio. Strength (fc), modulus of elasticity (Ec), shrinkage (épsilon\') and volume of permeable voids (VPP) of concretes were measured and the results were modeled using statistical tools. The results indicated that except the fc for concrete made with recycled red ceramic fine aggregate, the recycled aggregates lessens the concrete\'s behavior for all studied properties. It was also observed that the natural fine aggregate\'s substitution by recycled fine aggregates influences less in the concrete\'s behavior than the coarse aggregate\'s substitution, for all studied properties. To validate the proposed models, using other authors\' data, it was observed that such models describe the properties behavior very well, although such models don\'t produce properties values similar to the values published by the authors. It was also simulated, through the proposed models, the use of the recycled aggregates of C&D waste from some brazilian cities in concrete production and, in a general way, it was noticed a great viability in the use of the same ones, once the simulated concretes still reached considerable fc and Ec, mainly when the recycled fine aggregates was used. The recycled concrete\'s durability was also determined using the VPP increments in relation to a 0.46 water/cement ratio reference concrete. This classification suggests that the concretes with high tenors of substitution don\'t have a good behavior, being small tenors of substitution of fine aggregates more recommended. In general, it can be concluded that it is possible to use recycled aggregates, considering their variability, to produce concretes with satisfactory mechanical behavior and durability, considering the studied conditions.

Entre os desafios para a expansão de mercado da reciclagem, encontra-se o de viabilizar o emprego dos agregados de resíduos de construção e demolição (RCD) reciclados em concretos. No entanto as normas que regulamentam tal emprego não são facilmente aplicáveis nas usinas de reciclagem, existindo pouca informação sistemática de como as diferentes características dos agregados de RCD reciclados influenciam no desempenho do concreto. O objetivo desta tese é identificar as características dos agregados de RCD reciclados que exerçam influência relevante no comportamento mecânico dos concretos. As seguintes etapas experimentais são desenvolvidas: a) caracterização química e mineralógica das frações granulométricas de três amostras representativas de agregados, b) caracterização das propriedades físicas de agregados graúdos separados por densidade, assim como da composição química, mineralógica e por fases, c) influência das características dos agregados graúdos separados por densidade no comportamento mecânico dos concretos. Na caracterização dos agregados foram utilizados os seguintes métodos: análise granulométrica, análise química por FRX, análise mineralógica por DRX, determinação da fração solúvel por ataque com solução de HCl 33%, e análise termogravimétrica, separação por densidade empregando líquidos densos e equipamento “Sink and Float”, catação das fases, determinação da massa específica aparente e absorção de água dos agregados, dosagem e avaliação do comportamento mecânico de concretos produzidos com esses agregados. Os resultados permitem concluir que a porosidade (ou massa específica aparente) dos agregados de RCD reciclados controla o comportamento mecânico dos concretos produzidos com relação água e cimento constante, assim como a soma dos teores de aglomerantes e de cerâmica vermelha – frações mais porosas. A separação por densidade é uma técnica eficiente para separar esses agregados em subgrupos de diferentes porosidades, gerando concretos com comportamento mecânico e absorção de água similares. O estudo realizado aponta para uma densidade de corte em torno de 2,2 a 2,3 g/cm³. Os agregados contidos no intervalo “d> 2,2” possuem teores elevados de rochas e teores baixos de cerâmica vermelha, resultando em concretos com comportamento mecânico semelhante ao dos agregados naturais analisados. A avaliação da distribuição de densidade pode ser um método simples e rápido para a classificação de lotes desses agregados e controle do comportamento mecânico dos concretos produzidos. Na fração graúda e miúda, os teores de rochas e cerâmicas são superiores a 50% da massa, e o comportamento dos principais óxidos da composição química é semelhante. Esse comportamento muda significativamente na fração fina, em que predominam os aglomerantes e argilominerais (teores superiores a 77%). A origem (Itaquera e Vinhedo) e a cominuição influenciaram, de forma representativa, a distribuição de massa dos agregados graúdos de RCD reciclados separados por densidade. O agregado de Itaquera apresentou mais de 70% da massa no intervalo de densidade superior a 2,2 g/cm³.
Construction and demolition waste (CDW) recycled aggregates are not largely used in concrete due to CDW composition heterogeneity and CDW recycled aggregate physical property variability from visual classification and hand sorting of proposed standards that provide insufficient relation between the aggregate characteristics and concrete performance. This thesis aims to identify CDW recycled aggregate characteristics that influence the concrete mechanical performance. The experimental design was divided in three stages: a) detailed chemical and mineralogical characterization of three representative CDW recycled aggregate samples, b) characterization of the physical properties of the coarse CDW recycled aggregates separated by heavy media as well as the composition in terms of chemical, mineralogical, and visual phases, and c) the influence of the coarse CDW recycled aggregate separated by heavy media on concrete mechanical performance. The following methods were used: particle size distribution, chemical analysis by XRF, mineralogical analysis by XRD, soluble fraction in chloride acid leaching assay, thermal analysis, sequential heavy media and gravity separation, hand sorting, bulk specific gravity and water absorption, concrete mix design and its compressive strength and elastic modulus using the CDW recycled aggregates. In conclusion, CDW recycled aggregate porosity controls concrete mechanical performance formulated with constant cement and water relation. The concrete mechanical performance is related to bulk specific gravity of CDW recycled aggregates separated by density, including to the sum of binder and red ceramic content. Heavy media and gravity separation is efficient to separate CDW recycled aggregates in bulk specific gravity groups, producing concrete with similar concrete mechanical behavior and water absorption. Cutting density in 2.2-2.3 g/cm³ seems to be efficient since the aggregates with the upper density have high rock content resulting concrete mechanical performance similar to that produced using natural aggregates. Mass distribution in density separation could be a simple and fast method to classify CDW recycled aggregate and to control concrete mechanical performance. The coarse and sand fraction of CDW recycled aggregates had more than 50% in mass of rocks and ceramics, with quite similar main oxide contents in chemical composition. However, the contents changed in fine fraction (lower than 0.15 mm) whose binder content and clay minerals are in majority (upper to 77% in mass). The origin of CDW recycled aggregate and comminution influenced in mass distribution of sequential density separation. In Itaquera (São Paulo), the mass distribution upper to 2,2 g/cm³ was around 70%.

Os sólidos grosseiros, sedimentáveis e flutuantes são removidos no sistema de tratamento preliminar de estações de tratamento de esgoto e, de forma geral, dispostos em aterros sanitários e lixões, sem preocupação relacionada ao seu potencial de aproveitamento, redução, recuperação e impactos ambientais. Apesar da falta de importância atribuída, esses resíduos se mostram um dos problemas no gerenciamento de estações no que se refere ao manuseio, tratamento e destinação final. Nesse contexto, a presente pesquisa tem como objetivo demonstrar a potencialidade do aproveitamento dos resíduos removidos no tratamento preliminar de Estações de Tratamento de Esgoto (ETE), tomando-se como referência a ETE Monjolinho em São Carlos-SP (com capacidade de atendimento de 258.000 habitantes). Para atingir este propósito, foi avaliada a potencialidade do uso dos materiais removidos na unidade do tratamento preliminar, como fontes de energia e de matéria-prima, enfocando tema pouco explorado. Foram estudados os resíduos: i) removidos nos gradeamentos grosseiro e fino, visando seu uso como combustível; ii) o material sedimentável retido nos desarenadores, com intuito de utilizá-lo como agregado para argamassa e concreto não estrutural na construção civil; e, iii) os óleos e graxas removidos, visando o seu aproveitamento como insumo para produção de biocombustível; e também foi avaliada a degradação aeróbia e anaeróbia deste tipo de material. Em relação a cada tipo de resíduo foi possível verificar: i) a potencialidade da geração de energia a partir dos resíduos removidos nos gradeamentos de estações de tratamento de esgoto, tendo em vista os elevados resultados do poder calorífico inferior (4.837 kcal.kg-1 para resíduos do gradeamento grosseiro e 5.059 kcal.kg-1 para resíduos do gradeamento fino) e baixos valores na geração de cinzas (15,91% para resíduos do gradeamento grosseiro e 9,60% para resíduos do gradeamento fino); ii) a viabilidade técnica, econômica e ambiental da utilização da areia residual, removida nos desarenadores de ETEs, como agregado miúdo na incorporação de argamassas para revestimento e preparação de concreto não estrutural, desde que seja submetida ao procedimento de limpeza e secagem; iii) não foi possível obter biodiesel a partir do material flutuante removido nos desarenadores, uma vez que esse resíduo apresentou baixa concentração de óleos e graxas se comparado à outras matérias primas e grande quantidade de sólidos, sendo esses, em boa parte, de natureza orgânica, em consequência disso foi comprovada a potencialidade da degradação aeróbia e anaeróbia do material flutuante, resultando na redução de carga orgânica a ser aplicada nas unidades subsequentes do processo de tratamento.
The coarse, settleable and floating solids are removed in the system of preliminary treatment of the sewage treatment station and are generally disposed in landfills and dumps, regardless of their potential use, reduction, recovery and its environmental impacts. Despite the lack of recognizable relevance, such waste constitutes one of the problems in the management of stations with regard to the handling, treatment and disposal. In this context, the current investigation aims at demonstrating the potential of the use of the waste removed in the preliminary treatment of STPs, taking as reference the Monjolinho STP in Sao Carlos-Brazil (with service capacity of 258,000 population equivalent). To this end, we evaluated the potential use of the material removed in the primary treatment unit, as sources of energy and raw materials, focusing on underexplored topics. The following residues were studied: i) those removed in the coarse and fine screens, aiming its use as fuel; ii) the settleable material retained in the grit chambers, with the intention of using it as aggregate for mortar and nonstructural concrete in construction; and, iii) the oil and grease removed, using it a feedstock for biofuel production; and the aerobic and anaerobic degradations of such material were also evaluated. For each type of waste could be verified: i) the potential of generating energy from waste removed in the screens of the sewage treatment plant, due to the relatively high results of lower calorific value (4,837 kcal.kg-1 for waste collected in the coarse screens and 5,059 kcal.kg-1 for the fine screening residue) and low values regarding the generation of ash (15.91% and 9.60% for the coarse and fine screening, respectively); ii) technical, economic and environmental feasibility of the use of residual sand, removed in the grit chambers, as fine aggregate in the incorporation of mortars for coating and preparation of non-structural concrete, provided that it is submitted to cleaning and drying procedures; iii) it was not possible to obtain biodiesel from the floating material removed in the grit chambers, since this residue showed low concentration of oils and greases when compared to other raw materials and a high content of solids, largely organic in nature. Therefore, it was proved the potential for aerobic and anaerobic degradation of the floating material, resulting in the reduction of the organic load to be applied in the subsequent treatment process units.

Because FRP composites have high fiber strength and good durability, they are increasingly used for repairs, modernisation and reconstruction of concrete structures. In practice, however there is a risk of premature separation of FRP reinforcement from concrete. This can be avoided by appropriate selecting the fibers and the matrix and the appropriate shape of the reinforcement. The actual materials and consistency of FRP reinforcement with concrete are also covered by this diploma thesis.

En France, on compte plus de 340 millions de tonnes de déchets de déconstruction dans le secteur du bâtiment et des travaux publics. Parmi ces déchets, susceptibles d’être valorisés à condition qu’ils soient inertes, on trouve les granulats issus de vieux bétons et notamment des bétons produits dans les années 1960. Le processus de fabrication du ciment à l’échelle industrielle était tel qu’aujourd’hui, on ne peut pas exclure que ces bétons puissent contenir du chrome hexavalent. Mais la directive 2003/CE/53 concernant la production du ciment limite la teneur en chrome hexavalent à 2mg par kg de matière sèche. Il est par conséquent indispensable d’étudier, avant tout projet de valorisation, les interactions atmosphériques avec la matrice cimentaire et les dégradations par les eaux de pluie lors de leur mise en décharge ou durant leur cycle de vie.Le travail de cette thèse s’inscrit dans une étude de faisabilité du recyclage des déchets de déconstruction contenant du Cr (VI) et ayant subi différents types de dégradations naturelles, notamment la carbonatation atmosphérique. Une étude d’impact environnemental a été effectuée sur la base d’essais de lixiviation sur des matériaux de types monolithique et granulaire. Une étude de l’impact du pH sur les conditions de relargage a également été réalisée. L’interprétation des résultats expérimentaux utilise des modèles cinétiques, en particulier le modèle de Côte et Constable (1985), ainsi que les solutions d’interprétations graphiques des différentes normes utilisées.La campagne expérimentale a porté sur des mortiers confectionnés à base de granulats recyclés à des taux de 30% et 100% de substitution ainsi que sur des granulats recyclés à l’état brut. Les résultats obtenus ont montré que les matériaux étudiés (mortiers ou granulats seuls) sont inertes vis à vis du relargage du chrome hexavalent. Il a été démontré également, indépendamment de l’origine des granulats recyclés, de leur composition chimique et minéralogique et de leur taux de substitution dans les mortiers, que le relargage du chrome hexavalent reste négligeable. De même, une étude approfondie a été menée sur la structure du chrome au sein de la matrice cimentaire sous ces deux formes stables, trivalente et hexavalente. Les résultats obtenus ont montré que le chrome a tendance à se stabiliser dans l’ettringite, appelé Cr-ettringite dans le cas du Cr (VI) et dans la bentorite dans le cas du Cr (III).Enfin, il a été mis en évidence que la matrice cimentaire carbonatée a une aptitude à immobiliser le Cr (VI)
In France, it has been numerated more than 340 Million Tons of deconstruction wastes in the field of civil and public works.Among of these wastes, which are prone to be recycled if they are inert, are old aggregates concretes, especially which were produced in the 1960’s. The manufacturing process of cement on an industrial scale was similar to what is done today. Where, it cannot be excluded that these concretes may contain hexavalent chromium. However, the directive 2003/CE/53 concerning the production of cement limits the content of hexavalent chromium to 2 mg per kg of dry matter. Therefore, it is essential to study, before any upgrading project, the atmospheric interactions with the cement matrix and the degradation by rainwater during their landfill or during their life cycle.The thesis work takes part of a feasibility study on the recycling of waste deconstruction containing Cr (VI) and having undergone different types of natural degradations, including atmospheric carbonation. An environmental impact study has been performed on the basis of leaching tests on monolithic and granular materials. In addition, pH impact study on release conditions was also performed. The interpretation of the experimental results is based on the use of kinetic models, in particular the model of Côte & Constable (1985), as well as the solutions of interpretations graphs of the known different standards.The experimental campaign is focused on mortars confectioned from aggregates recycled at 30% and 100% substitution rates as well as recycled aggregates in the gross state. The obtained results are shown that the materials studied (mortars or aggregates alone) are inert with respect to the release of hexavalent chromium. t has been shown, independently from the origin of the recycled aggregates, their chemical composition, their mineralogy and their substitution rate in mortars, that the release of chromium hexavalent remains negligible. Similarly, an in-depth study was conducted on the chromium structure within the cementitious matrix under these two stable forms, trivalent and hexavalent. The results showed that chromium tends to stabilize in ettringite, with structure called Cr-ettringite in the case of Cr (VI) and in bentorite structure in the case of Cr (III).Finally, it has been shown that the cement matrix carbonation has an aptitude to trap and immobilize Cr (VI)

Bygg- och rivningssektorn står för ca 30% av Sveriges avfall enligt svenska miljöinstitutet IVL.Bevarande av energi som går åt vid tillverkning av material är gynnsamt för miljön, vilket ärsyftet med återbruk. När stomelement i dagsläget demonteras förlorar de CE-märkningen ochbetraktas därefter som avfall. En metod inom cirkulärt byggande är återvinning, vilket innebäratt bryta ner produkten för att antingen skapa energi eller nytt material. Vid återvinning bevarasinte energin vilket innebär att energin som går åt att tillverka produkten från start går förlorad.För att nå de klimatmål som EU och Sverige har satt till framtiden är det viktigt förbyggbranschen att sträva efter cirkulärt byggande, med fokus på återbruk och inte enbartåtervinning. Detta examensarbetes syfte är att undersöka hur man kan öka återbruksförmåganav stomelement. I Sverige används återbruk i en liten skala. För att användningen avstomelement ska utvecklas i en större skala måste tekniska lösningar framkomma redan iprojekteringsskedet. Oklarheter i regelverk kring klassificeringar av återanvända stomelement behöver tydliggörasför att öka återbrukspotentialen. Studien undersöker vilka möjligheter som finns idag av attbygga med återanvänt stommaterial, vilka hinder som uppstår och hur dessa problem kanhanteras. Detta undersöktes genom att intervjua respondenter med relevant kompetens ibyggbranschen samt genom en litteraturstudie. Studien avgränsas till att undersöka stomelementi trä, stål och betong. Resultaten visade att potentialen för återbruksmaterial i dagsläget inte är god på grund av att detinte finns konkreta regelverk och incitament samt att materialtillgången är begränsad.Stommaterial har höga konstruktionskrav på sig vilket gör det svårt att återbruka. Vidare visade resultaten från studien att det för närvarande inte finns tydliga standardprovningarför att säkerställa stomaterialens kvalitet och hållbarhet. Därför har denna studie tagit fram envägledande mall för att eventuellt minska förstörande provning samt agera som en guide föraktörer som vill återanvända stomelement men inte vet hur de ska gå tillväga.
The construction and demolition sector accounts for about 30% of Sweden's waste according tothe Swedish Environmental Institute IVL. Conservation of materials and energy used in themanufacture of materials is beneficial to the environment, which is the purpose of reusing. Whenstructural elements are currently dismantled, they lose their CE marking and are then regardedas waste. One method in circular construction is recycling, which means breaking down theproduct to either create energy or new material. During recycling, the energy is not conserved,which means that the energy used to manufacture the product from the start is lost. In order toachieve the climate goals that the EU and Sweden have set for the future, it is important for theconstruction industry to strive for circular construction, with a focus on reusing and not justrecycling. The purpose of this thesis is to investigate how to increase the reusability of structuralelements. In Sweden, recycling is used on a small scale. In order for the use of structuralelements to be developed on a larger scale, technical solutions must emerge during the designphase. Uncertainties of regulations regarding classifications of recycled structural elements need to beclarified in order to increase the reusing potential. The study examines what opportunities thereare today for building with reused structural materials, what obstacles arise and how theseproblems should be handled. This was investigated by interviewing respondents with relevantcompetence in the construction industry and through a literature study. The study is limited toexamining structural elements in wood, steel and concrete. The results showed that the potential for recyclable materials is currently not good due to thelack of regulations, incentives and that the supply of materials is limited. Structural materialshave high structural requirements, which make them difficult to reuse. Furthermore, the results from the study showed that there are currently no clear standard teststo ensure the quality and durability of the materials. Therefore, this study has developed aguiding template to possibly reduce destructive testing and act as a guide for companies whowant to reuse structure elements but do not know how to proceed.

Bygg- och rivningssektorn står för ca 30% av Sveriges avfall enligt svenska miljöinstitutet IVL. Bevarande av energi som går åt vid tillverkning av material är gynnsamt för miljön, vilket är syftet med återbruk. När stomelement i dagsläget demonteras förlorar de CE-märkningen och betraktas därefter som avfall. En metod inom cirkulärt byggande är återvinning, vilket innebäratt bryta ner produkten för att antingen skapa energi eller nytt material. Vid återvinning bevaras inte energin vilket innebär att energin som går åt att tillverka produkten från start går förlorad. För att nå de klimatmål som EU och Sverige har satt till framtiden är det viktigt för byggbranschen att sträva efter cirkulärt byggande, med fokus på återbruk och inte enbart återvinning. Detta examensarbetes syfte är att undersöka hur man kan öka återbruksförmågan av stomelement. I Sverige används återbruk i en liten skala. För att användningen av stomelement ska utvecklas i en större skala måste tekniska lösningar framkomma redan i projekteringsskedet. Oklarheter i regelverk kring klassificeringar av återanvända stomelement behöver tydliggöras för att öka återbrukspotentialen. Studien undersöker vilka möjligheter som finns idag av att bygga med återanvänt stommaterial, vilka hinder som uppstår och hur dessa problem kan hanteras. Detta undersöktes genom att intervjua respondenter med relevant kompetens i byggbranschen samt genom en litteraturstudie. Studien avgränsas till att undersöka stomelement i trä, stål och betong. Resultaten visade att potentialen för återbruksmaterial i dagsläget inte är god på grund av att det inte finns konkreta regelverk och incitament samt att materialtillgången är begränsad. Stommaterial har höga konstruktionskrav på sig vilket gör det svårt att återbruka. Vidare visade resultaten från studien att det för närvarande inte finns tydliga standardprovningar för att säkerställa stomaterialens kvalitet och hållbarhet. Därför har denna studie tagit fram en vägledande mall för att eventuellt minska förstörande provning samt agera som en guide för aktörer som vill återanvända stomelement men inte vet hur de ska gå tillväga.
The construction and demolition sector accounts for about 30% of Sweden's waste according to the Swedish Environmental Institute IVL. Conservation of materials and energy used in the manufacture of materials is beneficial to the environment, which is the purpose of reusing. When structural elements are currently dismantled, they lose their CE marking and are then regarded as waste. One method in circular construction is recycling, which means breaking down the product to either create energy or new material. During recycling, the energy is not conserved, which means that the energy used to manufacture the product from the start is lost. In order to achieve the climate goals that the EU and Sweden have set for the future, it is important for the construction industry to strive for circular construction, with a focus on reusing and not just recycling. The purpose of this thesis is to investigate how to increase the reusability of structural elements. In Sweden, recycling is used on a small scale. In order for the use of structural elements to be developed on a larger scale, technical solutions must emerge during the design phase. Uncertainties of regulations regarding classifications of recycled structural elements need to be clarified in order to increase the reusing potential. The study examines what opportunities there are today for building with reused structural materials, what obstacles arise and how these problems should be handled. This was investigated by interviewing respondents with relevant competence in the construction industry and through a literature study. The study is limited to examining structural elements in wood, steel and concrete. The results showed that the potential for recyclable materials is currently not good due to the lack of regulations, incentives and that the supply of materials is limited. Structural materials have high structural requirements, which make them difficult to reuse. Furthermore, the results from the study showed that there are currently no clear standard tests to ensure the quality and durability of the materials. Therefore, this study has developed a guiding template to possibly reduce destructive testing and act as a guide for companies who want to reuse structure elements but do not know how to proceed.