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Feng, Qiu Ling. "Chemical and microstructural investigations on slag hydration products." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 1989. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59672.
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Al-Kaisi, Ali Farhan. "Early age strength and creep of slag cement concretes." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329041.
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Boukendakdji, Mustapha. "Mechanical properties and long-term deformation of slag cement concrete." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236998.
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El-Khatib, Jamal M. "Durability related properties of PFA, slag and silica fume concrete." Thesis, University of Aberdeen, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315418.
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Concrete has the largest production of all man-made materials. Compared with other construction materials, it possesses many advantages including low cost, general availability of raw materials, low energy requirement and utilization under different environmental conditions. Therefore, concrete will continue to be the dominant construction material in the foreseeable future. However, durability of concrete and reinfored concrete structures are still of worldwide concern, so producing a good quality concrete which impedes the ingress of harmful substances into it is of paramount importance. Cement replacement materials have been introduced into concrete mixtures for the purpose of improving the durability performance. Hence, the aim of the present investigation is to study the durability of concrete with and without cement replacement materials under various initial curing conditions. In this thesis various concrete mixes with and without cement replacement materials were considered. The cement replacement materials were, pulverised fuel ash, condensed silica fume, and ground granulated blast furnace slag. Superplasticiser was added to the majority of the mixes considered and air entraining agent to some of the mixes. Various curing regimes were employed which comprised hot dry curing to simulate concrete in the hot arid areas in the world and curing at normal temperature. Curing involved air curing, membrane curing and moist curing for fourteen days followed by air curing. A number of tests were conducted at either one particular age or at various ages. These included tests on porosity and pore structure of pastes obtained by mercury intrusion porosimetry technique, water absorption which covers the water absorption of concrete obtained by shallow immersion and the water absorbed by capillary action when the concrete surface is in contact with water, sulphate resistance of concrete which is performed by immersing the concrete specimens in sulphate solution, and monitoring the change in length at various periods of immersion, chloride penetration profiles of concrete at various ages of exposure. In addition to these tests on durability related properties, tests on compressive strength were also performed. Throughout the study a correlation between pore structure and durability related properties is investigated. A comprehensive compilation of chloride penetration data is made and an empirical expression is derived for the prediction of long term diffusion coefficients. At the end of the investigation, limitations of the present study, conclusions and suggestions for future research are made.
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Muntasser, Tarek Ziad. "Properties and durability of slag based cement concrete in the Mediterranean environment." Thesis, University of Surrey, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247994.
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Khan, Saadat Ali. "Pore pressure and moisture migration in concrete at high and non uniform temperatures." Thesis, King's College London (University of London), 1990. https://kclpure.kcl.ac.uk/portal/en/theses/pore-pressure-and-moisture-migration-in-concrete-at-high-and-non-uniform-temperatures(9016d00a-3f08-4eb8-a9b3-a78d405d6686).html.
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Ryno, Barnard. "Mechanical properties of fly ash/slag based geopolymer concrete with the addition of macro fibres." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95866.
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Thesis (MEng) -- Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: Geopolymer concrete is an alternative construction material that has comparable mechanical
properties to that of ordinary Portland cement concrete, consisting of an aluminosilicate and
an alkali solution. Fly ash based geopolymer concrete hardens through a process called
geopolymerisation. This hardening process requires heat activation of temperatures above
ambient. Thus, fly ash based geopolymer concrete will be an inadequate construction material
for in-situ casting, as heat curing will be uneconomical.
The study investigated fly ash/slag based geopolymer concrete. When slag is added to the
matrix, curing at ambient temperatures is possible due to calcium silicate hydrates that form
in conjunction with the geopolymeric gel.
The main goal of the study is to obtain a better understanding of the mechanical properties of
geopolymer concrete, cured at ambient temperatures. A significant number of mix variations
were carried out to investigate the influence that the various parameters, present in the matrix,
have on the compressive strength of fly ash/slag based geopolymer concrete. Promising
results were found, as strengths as high as 72 MPa were obtained. The sodium hydroxide
solution, the slag content and the amount of additional water in the matrix had the biggest
influence on the compressive strength of the fly ash/slag based geopolymer concrete.
The modulus of the elasticity of fly ash/slag based geopolymer concrete did not yield
promising results as the majority of the specimens, regardless of the compressive strength,
yielded a stiffness of less than 20 GPa. This is problematic from a structural point of view as
this will result in large deflections of elements. The sodium hydroxide solution had the most
significant influence on the elastic modulus of the geopolymer concrete. Steel and polypropylene fibres were added to a high- and low strength geopolymer concrete
matrix to investigate the ductility improvement. The limit of proportionality mainly depended
on the compressive strength of the geopolymer concrete, while the amount of fibres increased
the energy absorption of the concrete. A similar strength OPC concrete mix was compared to
the low strength geopolymer concrete and it was found that the OPC concrete specimen
yielded slightly better flexural behaviour. Fibre pull-out tests were also conducted to
investigate the fibre-matrix interface. From the knowledge gained during this study, it can be concluded that the use of fly ash/slag
based geopolymer concrete, as an alternative binder material, is still some time away as there
are many complications that need to be dealt with, especially the low modulus of elasticity.
However, fly ash/slag based geopolymer concrete does have potential if these complications
can be addressed.<br>AFRIKAANSE OPSOMMING: Geopolimeerbeton is ‘n alternatiewe konstruksiemateriaal wat vergelykbare meganiese eienskappe
met beton waar OPC die binder is, en wat bestaan uit ‘n aluminosilikaat en ‘n alkaliese oplossing.
Vliegas-gebaseerde geopolimeerbeton verhard tydens ‘n proses wat geopolimerisasie genoem word.
Hierdie verhardingsproses benodig hitte-aktivering van temperature hoër as dié van die onmiddellike
omgewing. Gevolglik sal vliegas-gebaseerde geopolimeerbeton ‘n ontoereikende konstruksiemateriaal
vir in situ gietvorming wees, aangesien hitte-nabehandeling onekonomies sal wees.
Die studie het vliegas/slagmentgebaseerde geopolimeerbeton ondersoek. Wanneer slagment by die
bindmiddel gevoeg word, is nabehandeling by omliggende temperature moontlik as gevolg van
kalsiumsilikaathidroksiede wat in verbinding met die geopolimeriese jel vorm.
Die hoofdoel van die studie was om ‘n beter begrip te kry van die meganiese eienskappe van
geopolimeerbeton, wat nabehandeling by omliggende temperature ontvang het. ‘n Aansienlike aantal
meng variasies is uitgevoer om die invloed te ondersoek wat die verskeie parameters, aanwesig in die
bindmiddel, op die druksterkte van die vliegas/slagmentgebaseerde geopolimeerbeton het. Belowende
resultate is verkry en sterktes van tot so hoog as 72 MPa is opgelewer. Daar is gevind dat die
sodiumhidroksiedoplossing, die slagmentinhoud en die hoeveelheid water in die bindmiddel die
grootste invloed op die druksterkte van die vliegas/slagmentgebaseerde geopolimeerbeton gehad het.
Die styfheid van die vliegas/slagmentgebaseerde geopolimeerbeton het nie belowende resultate
opgelewer nie. Die meeste van die monsters, ongeag die druksterkte, het ‘n styfheid van minder as 20
GPa opgelewer. Vanuit ‘n strukturele oogpunt is dit problematies, omdat groot defleksies in elemente
sal voorkom. Die sodiumhidroksiedoplossing het die grootste invloed op die styfheid van die
vliegas/slagmentgebaseerde geopolimeerbeton gehad. Staal en polipropileenvesels is by ‘n hoë en lae sterke geopolimeer beton gevoeg om die buigbaarheid
te ondersoek. Die die maksimum buigbaarheid het hoofsaaklik afgehang van die beton se druksterkte
terwyl die hoeveelheid vesels die beton se energie-opname verhoog het. ‘n OPC beton mengsel van
soortgelyke sterkte is vergelyk met die lae sterkte geopolimeerbeton en daar is gevind dat die OPC
beton ietwat beter buigbaarheid opgelewer het. Veseluittrektoetse is uitgevoer om die veselbindmiddel
se skeidingsvlak te ondersoek.
Daar kan tot die gevolgtrekking gekom word dat, alhoewel belowende resultate verkry is, daar steeds
sommige aspekte is wat ondersoek en verbeter moet word, in besonder die styfheid, voordat
geopolimeerbeton as ‘n alternatiewe bindmiddel kan optree. Volgens die kennis opgedoen tydens hierdie studie, kan dit afgelei word dat die gebruik van
vliegas/slagmentgebaseerde geopolimeerbeton, as 'n alternatiewe bindmiddel, nog 'n geruime tyd weg
is, as gevolg van baie komplikasies wat gehandel moet word, veral die lae elastisiteitsmodulus. Tog
het vliegas/slagmentgebaseerde geopolimeerbeton potensiaal as hierdie komplikasies verbeter kan
word.
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Zheng, Yong Chu. "Shrinkage behaviour of geopolymers /." Connect to thesis, 2010. http://repository.unimelb.edu.au/10187/7157.
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Boltz, Daniel Edward. "Early performance of concrete pavement containing ground granulated blast furnace slag." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176839817.
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Almuwbber, Omar Mohamed. "The effect of different Ordinary Portland cement binders, partially replaced by fly ash and slag, on the properties of self-compacting concrete." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/1040.
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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Civil Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology<br>Self-compacting concrete (SCC) is a flowable self-consolidating concrete which can fill formwork without any external vibration. A self-compacting concrete mix requires the addition of superplasticiser (SP), which allows it to become more workable without the addition of excessive water to the mixture. The effect of different CEM I 52.5N cements produced by one company at different factories on self-compacting concrete was investigated. The properties of SCC are highly sensitive to changes in material properties, water content and addition of admixtures. For self-compacting concrete to be more accepted in South Africa, the effect that locally sourced materials have on SCC, partially replaced with extenders, needs to be investigated. The European guidelines for SCC (2005) determined the standard, through an extensive study, for the design and testing of self-compacting concrete. Using these guidelines, the properties of self-compacting concrete with the usage of local materials were investigated. The effect on SCC mixes was studied by using four cements; two types of SPs – partially replaced with two types of fly ash; and one type of slag. Mix design and tests were done according to the European Specification and Guidelines for Self-Compacting Concrete (2005). Using locally sourced materials (different cements, sand, coarse aggregate, fly ashes and slag), mixes were optimised with different SPs. Optimisation was achieved when self-compacting criteria, as found in the European guidelines, were adhered to, and the binders in these required mixes were then partially replaced with fly ash and slag at different concentrations. Tests done were the slump flow, V-funnel, L-box, sieve segregation resistance as well as the compressive strength tests. The results obtained were then compared with the properties prescribed by the European guidelines.
The cements reacted differently when adding the SPs, and partially replacing fly ash and slag. According to the tests, replacing cement with extenders – in order to get a sufficient SCC – seemed to depend on the chemical and physical properties of each cement type, including the soluble alkali in the mixture, C3A, C3S and the surface area. The range, in which the concentration of these chemical and physical cement compounds should vary – in order to produce an acceptable SCC partially replaced by extenders – was determined and suggested to the cement producer. The main conclusion of this project is that cement properties vary sufficiently from factory to factory so as to influence the performance of an SCC mix. The problem becomes even bigger when such cements are extended with fly ash or slag, and when different SPs are used. When designing a stable SCC mix, these factors should be taken into account.
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Bardella, Paulo Sergio. "Avaliação das propriedades fisicas e mecanicas de concretos produzidos com os cimentos Portland de alta resistencia inicial e de alto-forno aditivados com silica ativa curados termicamente." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257816.
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Orientador: Gladis Camarini<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo<br>Made available in DSpace on 2018-08-05T12:07:39Z (GMT). No. of bitstreams: 1
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Previous issue date: 2005<br>Resumo: A durabilidade das estruturas de concreto depende da estrutura porosa e da impermeabilidade do concreto, uma vez que a entrada de água e de agentes deletérios iniciam os processos patológicos que diminuem a vida útil de uma estrutura de concreto. Dessa forma, o objetivo deste trabalho foi avaliar a resistência mecânica, permeabilidade, absorção e carbonatação natural de concretos submetidos a diferentes condições de cura. Os procedimentos de cura adotados são normalmente utilizadds em canteiros de obra e na produção de estruturas pré-moldadas de concreto: cura imersa até a idade de 7 dias, cura ambiente e cura térmica. A cura térmica foi realizada na temperatura de 60°C. Foram empregados concretos produzidos com cimento Portland de Alta Resistência Inicial (CP V ARI) e cimento Portland de Alto Forno (CP III) sem e com sílica ativa (em substituição ao cimento na proporção de 10% em massa) para cada um dos diferentes tipos de cura utilizados. Os resultados evidenciaram que o tipo de cura afeta o desempenho do concreto. A mudança do tipo de cura aplicada proporcionou variações nas propriedades mecânicas e na durabilidade dos concretos, principalmente no que diz respeito à sua estrutura porosa. Assim, um regime de cura adequado é essencial para garantir a resistência mecânica e a durabilidade dos concretos. A utilização de sílica ativa em substituição ao cimento melhorou o desempenho dos concretos, tanto para a resistência mecânica quanto para a durabilidade, independente do tipo de cura empregado<br>Abstract: The durability of concrete structures depends on porous structure and its impermeability. The entrance of water and deleterious agents begin the damage processes and reduce the life of the concretestructure. ln that way, the aim of this work was to evaluate the mechanical resistance, permeability, absorption and natural carbonation of concretes submitted to different curing
procedures. The curing procedures adopted were usually used in civil construction and in the production of precast structures: moist curing until the age 6f 7 days, curing in air, and steam curing. The maximum temperature of steam curing was 60°C. All concretes were produced with High Early Strength Portland cement (CP V ARl) and Blastfurnace Portland cement (CP TIl) without and with silica fume (10% of replacement, by mass, of Portland cement) for each one of the different curing procedure used. The results showed that the curing procedure affects the concrete performance, providing variations in their mechanical properties and in their durability, mainly in porous structure. Therefore, the curing process used is essential to guarantee the mechanical resistance and the durability of the concretes. The use of silica fume improved the performance of the concretes, as for the mechanical resistance as for its durability, independent of the curing procedure used.<br>Mestrado<br>Edificações<br>Mestre em Engenharia Civil
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Rasool, Sava Tnar, and Omar Sharif. "Expansion of Sickla treatment plant : A study about the replacement of standard concrete to green concrete." Thesis, KTH, Betongbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278542.
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Stockholm Vatten has decided to close down the Bromma waste water treatment plantand manage the waste water from Bromma together with the waste water from the formerEolshällsverket to Henriksdal’s waste water treatment plant. Henriksdals wastewater treatment plant will be expanded for higher purification requirements and loads,estimated to be finished until 2040. This entails extensive renovations and additionsto the existing treatment plant in and on Henriksdalsberget, as well as a major expansionof the Sickla plant.The purpose of the study is to investigate an environmentally friendly alternative tothe standard concrete that will be used for the expansion of the Sickla plant. The largestenvironmental villain in concrete is the cement. The aim of this study has beento replace the cement with environmentally friendly additives in the largest possibleamount, thus reducing the negative impact of the cement on the environment.In the present study, a review was made of obtained data with exposure classes, then aliterature study was performed to gain knowledge in the area. With help from experts,two fictitious recipes for each exposure class have been calculated for the standardconcrete and the green concrete. In this way, a careful comparison between the concretetypes was made of the cement’s impact on global warming. Thereafter, a study wascarried out on existing EPDs, which were incorporated into the One Click LCA (2015)software. An LCA in the mentioned software was carried out, which enabled data to becompiled and a comparison of the climate impact between the four different fictitiousrecipes has been done.Compiled and compared data from LCA and analysis of EPDs show that 70% of thestructure with exposure class XD2 gets a 47% reduction in global warming when usinggreen concrete instead of standard concrete. Furthermore, the results show that theremaining 30% of the structure with exposure class XF3/XC4 gets a 20% reductionwhen using green concrete instead of standard concrete. The total reduction in globalwarming when using green concrete instead of standard concrete for the expansion ofSickla treatment plant was calculated to be 40%.<br>Stockholm Vatten har beslutat att lägga ned Bromma reningsverk och leda avloppsvattnetfrån Bromma tillsammans med avloppsvattnet från det forna Eolshällsverkettill Henriksdals reningsverk. Henriksdals reningsverk ska byggas ut för högre reningskravoch belastningar beräknade till år 2040. Detta medför omfattande om- och tillbyggnationeri det befintliga reningsverket i och på Henriksdalsberget samt en storutbyggnad av Sicklaanläggningen.Syftet med detta arbete är att undersöka ett miljövänligare alternativ till standardbetongensom ska användas vid utbyggnaden av Sicklaanläggningen. Då den främsta”miljöboven” i betongen är cementet har målet med denna studie varit att ersätta cementetmed miljövänliga tillsatsmaterial i största möjliga mängd, i syfte att minskacementets negativa inverkan på miljön.I föreliggande arbete har en genomgång utförts på erhållna data med exponeringsklasser,därefter påbörjades en litteraturstudie i syfte att inhämta kunskaper inomområdet. Med hjälp av experter har två fiktiva recept för respektive exponeringsklassräknats fram för standardbetongen och den gröna betongen. Med denna metod genomfördesen noggrann jämförelse mellan de olika recepten avseende cementets inverkanpå den globala uppvärmningen. Därefter undersöktes existerande EPD:er, vilka infogadesin i programvaran One Click LCA (2015). En LCA i den nämnda programvaranutfördes, vilket möjliggjorde att data kunde sammanställas och en jämförelse av klimatpåverkanmellan de fyra olika fiktiva recepten kunde genomföras.Sammanställd och jämförd data från LCA och analys av EPD:er visar att 70% av konstruktionenmed exponeringsklass XD2 får en reducering på 47% på den globala uppvärmningenvid användning av grön betong istället för standardbetong. Vidare visarresultatet att resterande 30% av konstruktionen med exponeringsklass XF3/XC4 fåren reduktion på 20% vid användning av grön betong istället för standardbetong. Dentotala reduktionen på den globala uppvärmningen vid användning av grön betongistället för standardbetong för utbyggnaden av Sickla reningsverk beräknades till 40%.
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Miah, Md Jihad. "The effect of compressive loading and cement type on the fire spalling behaviour of concrete." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3015/document.
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La recherche présentée dans cette thèse vise à examiner le mécanisme d’écaillage des bétons exposés au feu et comprendre l’influence du chargement mécanique appliqué en compression durant le chauffage. Des cubes (200 x 200 x 200 mm3) et des dalles (800 x 800 x 100 mm3) de béton fabriqués avec des ciments CEM II et CEM III (B40-II et B40-III: fc28days ≈ 40 MPa) ont été exposés à un feu ISO 834-1 sous différents niveaux de chargement uniaxial (cubes) et biaxial (dalles). En outre, l'effet du chargement mécanique (pression de confinement et charge uniaxiale) sur la perméabilité résiduelle au gaz a été étudié. Afin de mieux analyser les résultats expérimentaux et comprendre les mécanismes à l’origine de l'écaillage, des calculs numériques ont été réalisés en utilisant un modèle thermo-mécanique du code aux éléments finis CAST3M. Les résultats expérimentaux ont clairement montré que les éprouvettes chargées (uniaxial et biaxial) présentent un risque d’écaillage plus important que les éprouvettes non chargées. L’écaillage augmente avec le niveau de contrainte appliquée. Une partie des essais mais pas tous, ont montré que le B40-II (3% de laitier) présente un écaillage plus important que celui du béton B40-III (43% de laitiers).À partir de cette étude sur deux bétons ordinaires, il peut être mis en évidence qu'un certain niveau de contrainte de compression externe (uniaxiale ou biaxiale) est nécessaire pour induire l'écaillage du béton ordinaire. Les pressions des pores se combine avec les contraintes thermiques dûes aux gradients thermiques. Les contraintes de compression appliquées empêchent la création de certaines fissures générées par l'incompatibilité des déformations thermiques de la pâte de ciment et des granulats et des gradients thermiques. Pour l'échantillon non chargé, la création de fissures augmente la perméabilité et empêche naturellement le développement des pressions de pores.Pendant un feu réel, les membres structurels en béton sont toujours chargés ou retenus. La présence d'un chargement compressif pendant le chauffage augmente considérablement le stress de compression (diminue le stress de traction) et la grandeur de la pression des pores, ce qui augmente le risque d'écaillage. Ensuite, le stress compressif appliqué est un facteur clé très important que la conception de la résistance au feu des structures en béton devrait prendre en compte lors de l'écaillage. Par conséquent, il est recommandé que les essais d'écaillage ne soient pas effectués uniquement sur des échantillons non chargés<br>The research presented in this thesis seeks to examine and understand the mechanism of fire spalling role played by the external compressive loading during heating. Concrete cube (200 x 200 x 200 mm3) and slab (800 x 800 x 100 mm3) specimens made with CEM II and CEM III cements (B40-II and B40-III: fc28days ≈ 40 MPa) were exposed to ISO 834-1 fire curve under different levels of external uniaxial (for cube) and biaxial (for slab) compressive stress. Additionally, the effect of external compressive loading (confining pressure and uniaxial load) on the residual gas permeability of concretes have been investigated. In order to better analyse the experimental results and to provide more insight into the mechanism behind the fire spalling behaviour of concrete, numerical computations were carried out by using the existing thermo-mechanical model implemented in a finite element code CAST3M. The experimental results have clearly shown that the loaded specimens (uniaxial and biaxial) are more prone to spalling than unloaded specimens, with increasing amounts of spalling for higher values of applied compressive stress. Part of the tests, but not all have shown that B40-II (3% of slag) exhibited higher spalling than the B40-III (43% of slag).From this study on two ordinary concretes, it highlights that a certain level of external compressive stress (uniaxial or biaxial) was necessary to induce spalling. A possibility is that the applied compressive stress prevents the creation of cracks naturally due to thermal mismatch between cement paste and aggregates and thermal gradients. For unloaded specimen, the creation of cracks increases the permeability and naturally prevents the pore pressure to exceed a value that favours spalling.During a real fire, concrete structural members are always loaded or restrained. The presence of compressive loading during heating significantly increases the compressive stress (decreases the tensile stress) and the magnitude of pore pressure, which increase the risk of fire spalling. Then, the applied compressive stress is a very important key factor that the fire resistance design of concrete structures should take into account when considering spalling. Hence, it is recommended that the fire spalling test should not be carried out only on unloaded specimens, especially for the ordinary concrete
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Lübeck, André. "RESISTIVIDADE ELÉTRICA DE CONCRETOS DE CIMENTO PORTLAND BRANCO E ELEVADOS TEORES DE ESCÓRIA DE ALTO FORNO." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/7691.
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The electrical resistivity is an important concrete property that allows evaluating the access facility of aggressive agents before the corrosion process begins and estimates the velocity of the same process after it begun. The electrical resistivity and the oxygen availability are the characteristics that control the corrosion velocity. This work aimed to evaluate the performance of white Portland cement concretes with high blast furnace slag content and chemical activation on the electrical resistivity. Other properties were measured, as axial compressive strength, porosity and specific electrical conductivity of pore solution. Four mixtures were tested, a reference one, only with white Portland cement as binder, a second one, with 50% of blast furnace slag in substitution of cement, other with 70% slag content, and the last one, with 50% of slag and alkaline activation, 4% of Na2SO4. The water/binder ratios were fixed at 0,30, 0,42 and 0,55 for all samples. The electrical resistivity was measured using the four electrode method (Wenner method). The sample age, water/binder ratio and the slag content have an expressive effect over the electrical resistivity, especially because it results in changes of the pore structure. The electrical resistivity grows as the amount of slag increases. The increase of slag amount also results in smaller specific electrical conductivity of pore solution and pore structure refinement. On the other hand, the axial compressive strength decreases as the slag amount increases. The biggest resistivity results were obtained for the mixture with 70% of slag. This mixture showed the best cost/benefit ratio as compressive strength were fixed at 35 and 55 MPa, at 28 days, and 60 MPa, at 91 days.<br>A resistividade elétrica é uma importante propriedade do concreto por permitir avaliar a facilidade de acesso de agentes agressivos antes de instalado o processo corrosivo e estimar a velocidade do mesmo depois de instalado, sendo conjuntamente com a disponibilidade de oxigênio um dos parâmetros determinantes para a velocidade da corrosão. Este trabalho teve como objetivo avaliar o desempenho de concretos de cimento Portland branco com elevados
teores de escória de alto forno e ativação química quanto à resistividade elétrica aparente. Foram avaliadas além da resistividade outras grandezas como resistência à compressão,
porosidade e condutividade específica da solução dos poros. Foram investigadas quatro misturas, uma de referência contendo apenas cimento, uma segunda com teor de substituição de cimento por escória de 50%, outra com teor de substituição de 70% e uma última contendo 50% de escória e ativador alcalino, Na2SO4, em um teor de 4%. As relações água/aglomerante foram fixadas em 0,30, 0,42 e 0,55 para todas as misturas. A medida da resistividade elétrica
foi realizada através do método dos quatro eletrodos (Wenner). A resistividade elétrica se mostrou dependente da idade, relação a/ag e teor de escória, principalmente, em função das alterações que estas proporcionam na estrutura de poros da pasta. A resistividade cresceu proporcionalmente ao aumento do teor de escória. O aumento do teor de escória resultou também em menor condutividade da solução aquosa e refinamento da estrutura de poros da pasta. Por outro lado, a resistência à compressão diminuiu com o crescimento do teor de escória. Os maiores valores de resistividade elétrica foram apresentados pela mistura contendo 70% de escória. Esta mistura se mostrou a de melhor relação custo/benefício quando se fixaram valores de resistência à compressão de 35 e 55 MPa, aos 28 dias, e 60 MPa, aos 91 dias.
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Van, Rompaey Gilles. "Etude de la réactivité des ciments riches en laitier, à basse température et à temps court, sans ajout chloruré." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210780.
Full textAbstract:
Le ciment Portland est de loin le liant hydraulique le plus connu et utilisé depuis de très nombreuses années tant dans le secteur de la construction civile qu’au niveau du stockage des déchets (barrières ouvragées ou matériau de confinement). Le processus industriel qui donne naissance au clinker, constituant de base du ciment Portland, n’a pas subi de modifications depuis des décennies. <p>Par ailleurs, au cours de ces dernières années, certaines considérations telles que le réchauffement climatique et le développement durable ont mis à mal les industries qui émettent des gaz à effets de serre et qui sont grosses consommatrices d’énergie. <p>Or, la production de ciment Portland n’est pas uniquement consommatrice de calcaires, d’argiles, de marnes et de combustibles fossiles, elle produit et libère ces gaz à effets de serre tels que le dioxyde de carbone (CO2) et l’hémioxyde nitreux (N2O). Le dioxyde de soufre (SO2), l’acide chlorhydrique (HCl) ainsi que d’autres oxydes d’azote (NOx) sont également émis lors du processus de fabrication du clinker. Le secteur des matériaux de construction contribue de façon importante aux émissions de CO2, le principal responsable du réchauffement climatique.<p>La problématique majeure de l’industrie cimentière provient d’un simple processus chimique de transformation :la décarbonatation du calcaire ou de la craie, débutant vers 550°C, qui forme de la chaux (CaO) et qui libère du dioxyde de carbone selon la réaction suivante :<p><p>CaCO3 =\<br>Doctorat en sciences, Spécialisation géologie<br>info:eu-repo/semantics/nonPublished
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Khokhar, Muhammad Irfan. "Optimisation of concrete mix design with high content of mineral additions: effect on microstructure, hydration and shrinkage." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209985.
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The cement being used in the construction industry is the result of a chemical process<p>linked to the decarbonation of limestone conducted at high temperature and results in a<p>significant release of CO2. This thesis is part of the project EcoBéton (Green concrete) funded<p>by the French National Research Agency (ANR), with a purpose to show the feasibility of<p>high substitution of cement by mineral additions such as blast furnaces slag, fly ash and<p>limestone fillers. Generally for high percentages of replacements, the early age strength is<p>lower than Portland cement concrete. To cope with this problem, an optimisation method for<p>mix design of concrete using Bolomey’s law has been proposed. Following the encouraging<p>results obtained from mortar, a series of tests on concretes with different substitution<p>percentages were carried out to validate the optimisation method. To meet the requirements of<p>the construction industry related to performance of concrete at early age, which determine<p>their durability, a complete experimental study was carried out. Standard tests for the<p>characterization of the mechanical properties (compressive strength, tensile strength, and<p>setting) allowed to validate the choice of mix design on the basis of equivalent performance.<p>We focused on the hydration process to understand the evolution of the mechanical<p>properties. Setting time measurement by ultrasound device at different temperatures (10°C,<p>20°C and 30°C) showed that ground granulated blast furnace slag (GGBFS) and fly ash<p>delayed the setting process, while use of limestone filler may accelerate this process.<p>Calorimetric studies over mortars and concretes made possible to calculate the activation<p>energy of the different mixtures and a decrease in heat of hydration of concretes with mineral<p>additions was observed which is beneficial for use in mega projects of concrete. Scanning<p>Electron Microscopy observations and thermal analysis have given enough information about<p>the hydration process. It was observed that the hydration products are similar for different<p>concrete mixtures, but the time of their appearance and quantity in the cement matrix varies<p>for each concrete mix.<p>Last part of the thesis was dedicated to the study of main types of shrinkage. First of all,<p>deformations measured were correlated to hydration, capillary depression and porosity<p>evolution. Results allowed concluding that the use of mineral additions has an actual effect on<p>the plastic shrinkage behaviour, but its impact is not proportional to the percentage of<p>additions. Substitution of cement by the additions seems to have a marked influence on the<p>kinetics of the shrinkage without any effect on its long term amplitude. The study of<p>restrained shrinkage under drying conditions by means of ring tests showed that concretes<p>with high percentage of slag addition seem more prone to cracking than the Portland cement<p>concretes.<br>Doctorat en Sciences de l'ingénieur<br>info:eu-repo/semantics/nonPublished
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Fialová, Barbora. "Rehydratace alkalicky aktivované strusky po vysokoteplotním namáhání." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-239940.
Full textAbstract:
Ground granulated blast furnace slag is a by-product of the steel industry and is often used in combination with ordinary Portland cement as a binder in concrete. When concrete is exposed to high temperatures, physical and chemical transformations lead to significant loss of mechanical properties. This study aims to investigate the effect of high temperatures and rehydration on the mechanical properties, microstructure and phase composition of alkali activated slag. The results of the research could make an important contribution to decisions made concerning the reconstruction of structures affected by fire. In suitable cases it would be possible to regenerate parts of a structure instead of totally rebuilding it.
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Tolloczko, J. J. A. "Time dependent properties of heat cycled slag cement concretes." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376503.
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Darquennes, Aveline. "Comportement au jeune âge de bétons formulés à base de ciment au laitier de haut-fourneau en condition de déformations libre et restreinte." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210239.
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A l’heure actuelle où la préservation de notre environnement est primordiale, les constructions en béton font intervenir de plus en plus des ciments comprenant des ajouts minéraux, tels que le laitier, les cendres volantes… En effet, la production des ciments composés permet de réduire le dégagement des gaz à effets de serre et de réutiliser des déchets industriels. Les bétons formulés à base de ciment au laitier de haut-fourneau (CEM III) sont également largement utilisés suite à leur bonne résistance aux réactions alcali-silices, à la diffusion des chlorures et aux attaques sulfatiques… Cependant, certains ouvrages construits avec ce type matériau ont présenté au jeune âge des problèmes de fissuration liés à la restriction de leurs déformations différées, telles que le retrait endogène, thermique et de dessiccation. Suite à cette observation, des essais préliminaires ont été réalisés au laboratoire du service BATir de l’Université Libre de Bruxelles. Ils ont mis en avant plusieurs caractéristiques du comportement de ces matériaux :<p><p>1. Lors du suivi du retrait restreint à l’aide de l’essai à l’anneau en condition de dessiccation, le béton formulé à base de ciment au laitier de haut-fourneau a fissuré bien avant le béton formulé à base de ciment Portland.<p>2. Le retrait total en condition libre du béton formulé à base de ciment au laitier de haut-fourneau est nettement supérieur à celui du béton formulé à base de ciment Portland. Cette différence de comportement est principalement due à l’accroissement rapide et plus élevé du retrait endogène des bétons formulés à base de ciment au laitier de haut-fourneau.<p><p>Au vu de ces résultats expérimentaux, il a semblé intéressant de déterminer quel était l’impact de la déformation endogène des bétons formulés à base de ciments au laitier de haut-fourneau (CEM III) sur leur sensibilité à la fissuration. Afin de répondre à cette question, les déformations différées (retrait endogène, fluage propre en compression et en traction) au jeune âge de trois compositions de béton avec différentes teneurs en laitier (0, 42 et 71%) ont été étudiées expérimentalement en conditions libre et restreinte. Cependant, le suivi du retrait endogène libre et restreint a nécessité le développement de plusieurs dispositifs expérimentaux limitant au maximum les artefacts de mesure, tels que la TSTM (Temperature Stress Testing Machine). De plus, l’interprétation de ces résultats expérimentaux a également nécessité une caractérisation du comportement de ces matériaux à l’échelle macro- et microscopique. <p><p>Finalement, cette étude a montré que malgré une déformation endogène plus élevée, les bétons formulés à base de ciment au laitier de haut-fourneau fissurent après le béton formulé à base de ciment Portland. Ce comportement est dû à :<p>-l’impact du laitier sur la réaction d’hydratation du matériau cimentaire ;<p>-la présence d’une expansion de la matrice cimentaire des bétons formulés à base de ciment au laitier de haut-fourneau au jeune âge qui retarde l’apparition des contraintes de traction au sein du matériau ;<p>-la plus grande capacité de ces matériaux cimentaires à relaxer les contraintes de traction/<p>Today, the use of concretes with mineral additions (fly ash, slag) for civil engineering structures is spreading worldwide. Indeed, the production of blended cements is more respectful of the environment than the production of Portland cement, because it allows reducing greenhouse gas emissions and using industrial wastes. Slag cement concretes are also largely used for their good resistance to alkali-silica reactions, sulphate attacks and chloride diffusion. However, some of constructions built with slag cement concretes have exhibited cracking at early age due to their restrained deformations, such as thermal, autogenous and drying shrinkage. Following these observations, a preliminary experimental study was realized in the laboratory of BATir Department at ULB. It revealed several characteristics of the behaviour of slag cement concretes:<p>1. The study of restrained deformations under drying conditions by means of ring tests showed that the slag cement concretes seem more prone to crack than the Portland cement concretes;<p>2. The total free shrinkage for slag cement concrete is clearly larger than for Portland cement concrete. This difference of behaviour is mainly due to the fast and large increase in the autogenous deformation of the slag cement concrete.<p><p>Following these experimental results, the effect of the autogenous deformation on the cracking sensibility of slag cement concretes seemed interesting to investigate. Their deformations (autogenous deformation, compressive and tensile basic creep) have been studied at early age for three concretes characterized by different slag contents (0, 42 and 71%) under free and restrained conditions. For monitoring free and restrained autogenous deformations, several test rigs aimed at limiting artefacts were designed, like the TSTM (Temperature Stress Testing Machine). Moreover, the behaviour of these concretes was also characterized by a study at a macro- and microstructure scale.<p><p>Finally, this study shows that the slag cement concretes under sealed and fully restrained conditions crack later than the Portland cement concrete, despite the fact that they are characterized by the largest autogenous deformation. This behaviour is due to:<p>- the slag effect on the hydration reaction of cementitious material;<p>- the cement matrix expansion of the slag cement concretes at early age which delays the occurrence of tensile stresses inside the material;<p>- the largest capacity of this concrete to relax tensile stresses.<p><br>Doctorat en Sciences de l'ingénieur<br>info:eu-repo/semantics/nonPublished
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Morrison, Jill A. "Effects of slab Shape and load transfer Mechanisms on Portland cement concrete pavement." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1177012605.
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Veleba, Ondřej. "Studium vlivu složení na mechanické vlastnosti vysokohodnotného betonu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216217.
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This work is devoted to study the influence of the composition on mechanical properties of high performance concret based on portland cement. 29 samples of high performance concrete (HPC) warying in composition were prepared. The constituents used for HPC preparation were: cement Aalborg White, silica fume, finelly ground blast furnace slag, finelly ground silica, calcinated bauxite and polycarboxylate based superplasticizer. The mechanical parameters (flexural and compressive strength) of the samples were observed after 7 and 28 days of moist curing. Compressive strength values after 28 days were in the range of 92 to 194 MPa and the flexural strength values were in the range of 7 to 23 MPa (without using of fiber reinforcement). The graphs showing mechanical parameters depending on the mixture composition were constructed and consequently evaluated.
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Goldsberry, Benjamin M. "Thermal effect curling of concrete pavements on U.S. 23 test road (DEL 23-17.28." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176832475.
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Feizi, Sedige, and Fateha Yasmin Khan. "Study of crack width within a suspended concrete slab with different amount of cement clinker considering lower climate impact." Thesis, KTH, Betongbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-222024.
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This master thesis investigates the possibility of using a concrete recipe with only 70 % cement clinker for a building project named Gretas Glänta, regarding the demands of cracking for a suspended slab. The requirement to fulfill was a maximum crack width of 0.2 mm due to drying shrinkage and long- term loading. The purpose of using a lower amount of cement clinker in the concrete mix is to reduce the climate impact from the concrete. The thesis considers material testing and modelling of different concrete recipes with variation of the amount of cement clinker. Fly ash was used as the alternative binder. A total of five concrete mixes was tested. One mix with 100% cement clinker was through laboratory testing compared to mixes with 85 % and 70 % cement clinker content. A concrete mix with only 50 % cement clinker was also tested, but this mix is today not allowed according to the concrete standards, but was included in the study to test different material properties of the fresh and hardened concrete. All concrete mixes were tested with the effectivity factor 1, except for the recipe with 70 % cement clinker, which was tested for effectivity factors of 1 and 0.4. The performed study showed that the concrete mix 4 with 70 % cement clinker and with the effectivity factor 0.4 reached the strength class C35/45 after 28 days and also fulfilled the specified requirement of a maximum crack width of 0.2 mm due to drying shrinkage and long-term loading. Water permeability test showed that the concrete mix with 70 % cement clinker and an effectivity factor of 0.4 was waterproof. The concrete mix 3 with 70 % cement clinker and the effectivity factor 1 reached a strength class C30/37. The concrete mix 1 with 100 % cement clinker obtained the highest strength class C50/60 and the mix 2 with 85 % cement clinker reached strength class C45/55. The concrete mix 5 with 50 % cement clinker reached the strength class C20/25 which is the lowest strength class among the tested recipes. All the concrete recipes seemed to be waterproof according to the water permeability test. A background description of carbon dioxide emission from concrete and cement production is presented in the report. Research about ongoing methods to minimize the emission from concrete and cement industry is also summarized. FE-modelling with the software FEM-design and analytical calculations were performed to investigate the crack width due to drying shrinkage and long-term loading for the slab, for concrete mix 2 with 85 % cement clinker with effectivity factor 1 and mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4. The properties obtained from the laboratory tests were used in the modelling and analytical calculations. Results from FEM-design and analytical calculations showed that concrete mixes 3 and 4 with 70 % cement clinker and effectivity factors of 1 and 0.4, and the concrete mix 2 with 85 % cement clinker with effectivity factor 1, fulfilled the demand on crack width. The calculation was not performed for concrete mixes 1 and 5 with 100 % and 50 % cement clinker, respectively, because they were not to be used in the building project. The results from the performed study showed that concrete mix 4 with 70 % cement clinker and an effectivity factor of 0.4 can be used in the building project Gretas Glänta in order to lower the climate impact from the concrete.<br>Examensarbetet undersöker möjligheten att använda ett betongrecept med endast 70 % cementklinker för ett husbyggnadsprojekt kallat Gretas Glänta med hänsyn till krav på sprickbildning i en fribärande platta. Kravet som ska uppfyllas är en sprickvidd på max 0.2 mm med hänsyn till krympning och långtidsbelastning. Syftet med att använda en lägre andel cementklinker i betongblandningen är att minska klimatpåverkan från betongen. Examensarbetet består av materialförsök och konstruktionsteknisk modellering för olika betongrecept, där andelen cementklinker varieras. Flygaska användes som alternativt bindemedel. Totalt undersöktes fem betongmixer. En mix med 100 % cementklinker jämfördes genom laboratorietestning med motsvarigheter med 85 % och 70 % cementklinkerinnehåll. Ett betongrecept med 50 % cementklinker undersöktes också i detta examensarbete, trots att detta idag inte tillåts enligt betongstandarderna, men inkluderades i studien för att testa olika materialegenskaper i färskt och hårdnat tillstånd. Alla betongmixerna testades med effektivitetsfaktorn 1 förutom receptet med 70 % cementklinkerandel som testades för både 1 och 0.4 i effektivitetsfaktor. Den genomförda studien visade att betongmix 4 med 70 % cementklinker och med effektiviseringsfaktor 0.4 uppnådde hållfasthetsklass C35/45 efter 28 dagar och uppfyllde också angivet krav på maximal sprickbredd 0,2 mm med hänsyn till krympning och långtidslast. Vattenpermeabilitetstest visade att betongmixen med 70 % cementklinker och effektiviseringsfaktor 0.4 var vattentätt. Betongmix 3 med 70 % cementklinker och effektivitetsfaktor 1 uppnådde hållfasthetsklass C30/37. Betongmix 1 med 100 % cementklinker erhöll den högsta hållfasthetsklassen C50/60 och betongmix 2 med 85 % cementklinker gav hållfasthetsklass C45/55. Betongmix 5 med 50 % cementklinker uppnådde hållfasthetsklass C20/25 vilket var den lägsta av de testade betongrecepten. Alla betongrecepten verkade ge vattentät betong enligt vattenpermeabilitetstest. En bakgrundsbeskrivning av koldioxidutsläpp från betong- och cementproduktion genomförs i rapporten. Forskning om pågående metoder för att minimera utsläppen från betong- och cementindustrin sammanfattas också. FE-modellering med programmet FEM-design och analytiska beräkningar utfördes för att undersöka sprickbredden med hänsyn till krympning och långtidslast för betongplattan för betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 och betongmixerna 3 och 4 med 70 % cementklinker och effektiviseringsfaktorerna 1 och 0.4. Egenskaperna som erhölls i laboratorietesterna användes i modellerings och de analytiska beräkningarna. Resultat från FEM-design och analytiska beräkningarna visade att betongmixerna 3 och 4 med 70 % cementklinker med effektiviseringsfaktorerna 1 och 0.4 och betongmix 2 med 85 % cementklinker och effektiviseringsfaktor 1 uppfyllde kravet på sprickbredd. Beräkningen utfördes inte för betongmixerna 1 och 5 med 100 % cementklinker och 50 % cementklinker då de inte var aktuella för att användas i bostadsprojektet. Resultaten från den genomförda studien visade att betongmix 4 med 70% cementklinker och med en effektivitetsfaktor 0.4 kan användas i husbyggnadsprojektet Gretas Glänta för att sänka klimatpåverkan från betongen.
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Dellinghausen, Luciano de Medeiros. "Retração total e penetração de cloretos em concretos com cimento Portland branco e escória de alto forno." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/7730.
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Drying Shrinkage is a phenomenon that occurs in concrete, subjected or not to a load, due to water loss, once exposed to environment and allowed to dry. It is
responsible for almost the entire total shrinkage strain in concrete. A concrete element with restrained shrinkage deformation may develop tensions that cause cracks, allowing the ingress of aggressive agents that may cause some damage to the reinforcement, reducing, consequently, its strength and durability. The most common aggressive agent into concrete is the chloride ion, which is considered the great responsible for the early reinforcement corrosion of concrete structures, affecting its stability and durability. Corrosion of reinforcement bars due to the ingress of salts from sea water into concrete is recognized to be the most influent factor in
the destructive mechanisms for marine structures. The use of mineral admixtures such as blast furnace slag, the increase of curing duration and the water/binder ratio
reduction are measures that may reduce the chloride ion penetration. The aim of this study was to investigate the influence of the cement replacement content by slag, as
well as the duration of curing on drying shrinkage, chloride ion penetration and compressive strength of concretes made with high early age strength cement and
white Portland cement. Water-binder ratios of 0.30, 0.42 and 0.55, curing duration of 3 and 7 days, besides the cement replacement contents of 0%, 50% and 70% were
investigated. In order to analyze the influence of the alkali activation on the properties investigated, a concrete made with 50% white Portland cement replacement content by slag and activated by sodium sulfate (4% in mass of binder) was used. The compressive strength was evaluated in the ages of 3, 7, 28 and 91 days; the drying
shrinkage in the ages of 7, 14, 21, 28, 35, 56, 91 and 182 days, and the chloride ion penetration (immersion test in chloride solution) in the ages of 7, 14, 28, 56 and 91
days. Before being immersed in the chloride solution, the specimens were subjected to a drying period of 91 days. The results obtained revealed that an increase in the
slag content decreased the compressive strength and the drying shrinkage values, besides the smaller depths of chloride penetration with both cements used. Reducing
the curing duration resulted greater drying shrinkage and depth of chloride penetration for both cements, independently the slag content.<br>A retração hidráulica é um fenômeno que ocorre no concreto, submetido ou não a carregamento, devido à perda de umidade, uma vez exposto ao meio ambiente e permitida sua secagem. Ela é responsável por praticamente toda a
deformação total por retração no concreto. Um elemento de concreto com restrição de deformação por retração pode desenvolver tensões que levam à formação de fissuras, através das quais agentes agressivos podem penetrar e causar algum dano à armadura, reduzindo sua resistência e durabilidade. O agente agressivo mais comum é o íon cloreto, o qual é considerado como a maior causa de corrosão
prematura das barras de armaduras das estruturas de concreto, afetando sua estabilidade e vida útil. A corrosão de armaduras devido ao ingresso de íons cloretos da água do mar no concreto é universalmente conhecida como o fator de maior
influência nos mecanismos destrutivos de estruturas marinhas. A utilização de adições minerais como a escória de alto forno, o aumento no prazo de cura e a redução na relação água/aglomerante são medidas que podem diminuir a
penetração desses íons no concreto. Este trabalho teve por objetivo investigar a influência do teor de escória e do período de cura na retração hidráulica, na penetração de íons cloretos e na resistência à compressão axial de concretos compostos de cimento Portland de alta resistência inicial e cimento Portland branco estrutural. Foram adotadas relações água/aglomerante de 0.30, 0.42 e 0.55, teores de escória, em substituição ao cimento Portland, de 0%, 50% e 70%, além de
períodos de cura de 3 e 7 dias. Foi empregada uma mistura composta de 50% de escória em substituição ao cimento Portland branco, ativada quimicamente por sulfato de sódio (4% da massa de aglomerante) para analisar a influência do
ativador nas propriedades investigadas. As idades avaliadas para o ensaio de resistência à compressão foram de 3, 7, 28 e 91 dias; para retração hidráulica idades de 7, 14, 21, 28, 35, 56, 91 e 182 dias e, para penetração de íons cloretos (imersão
em solução salina) as idades de 7, 14, 28, 56 e 91 dias. Antes de serem imersos em solução salina os corpos-de-prova foram submetidos a um período de secagem de 91 dias. Dos resultados obtidos, constatou-se que o aumento do teor de escória resultou em decréscimo nos valores de resistência à compressão, de retração e de penetração de cloretos para os dois cimentos investigados. A diminuição no período
de cura resultou em maiores valores de retração e de penetração de cloretos, tanto no concreto branco quanto no cinza, independentemente do teor de escória utilizado.
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Munhoz, Flávio André da Cunha. "Efeito de adições ativas na mitigação das reações álcali-sílica e álcali-silicato." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-10012008-100734/.
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A reação álcali-agregado é uma manifestação patológica diretamente ligada à seleção dos materiais (cimento, agregados miúdo e graúdo, água e aditivos) que pode comprometer a durabilidade das estruturas de concreto, uma vez que a interação desses materiais e as condições ambientais é que vão conferir ao concreto determinadas propriedades ligadas à sua vida útil. A reação entre os hidróxidos alcalinos solubilizados na fase líquida dos poros dos concretos e alguns agregados reativos é lenta e resulta em um gel que, ao se acumular em vazios do concreto e na interface pasta-agregado, na presença de água, se expande, exercendo pressão interna no concreto. Ao exceder a resistência à tração do concreto, a pressão interna pode promover fissurações. A reação álcali-agregado requer a atuação conjunta de água, agregado reativo e álcalis. Sua prevenção pode ser feita a partir da eliminação de um dos fatores, ou seja, a partir do emprego de agregados inertes ou de cimentos com baixos teores de álcalis ou isolamento da umidade. Na impossibilidade de eliminar um dos fatores, medidas preventivas devem ser tomadas para o emprego de agregados reativos em obras de construção civil. Entre essas, destacam-se a utilização de cimentos com baixos teores de álcalis ou a de cimentos com adições ativas mitigadoras da reação álcali-agregado: escória de alto-forno, cinza volante, metacaulim e sílica ativa, que foi o objeto de pesquisa do presente trabalho. No programa experimental foram analisados dois tipos de agregado potencialmente reativos com os hidróxidos alcalinos: EDVDOWR e PLORQLWR_ JUDQtWLFR. O primeiro, proveniente de rocha ígnea, tem como constituintes deletérios vidro, clorofeíta, calcedônia (sílica criptocristalina), que dará origem à reação do tipo iOFDOL_VtOLFD. O agregado milonito granítico provém de rocha metamórfica, tem como constituintes deletérios quartzo microgranular, quartzo recristalizado, quartzo com extinção ondulante e quartzo e feldspato deformados, que dará origem ao tipo de reação iOFDOL_VLOLFDWR. Com o objetivo de avaliar a eficiência de adições ativas em mitigar as reações, os agregados foram combinados com 16 cimentos com adições ativas. Escória de alto-forno foi adicionada a 15%, 30%, 45% e 60% e cinza volante, a 10%, 15%, 25% e 35%, teores normalmente encontrados nos cimentos brasileiros. Metacaulim foi adicionada a 5%, 10%, 15% e 20%, e sílica ativa, a 5%, 10% e 15%, teores representativos da faixa normalmente adicionada diretamente a concretos. Todos os materiais utilizados foram caracterizados química, física e mineralogicamente, incluindo a análise petrográfica dos agregados. As barras de argamassa foram analisadas ao MEV, microscópio óptico de luz transmitida, realizaram-se ensaios de porosimetria por intrusão de mercúrio e análises térmicas para quantificar a teor de portlandita residual, e determinou-se o teor de álcalis dentro das barras após a realização dos ensaios para verificar a migração de íons de sódio. Os resultados indicam que a eficiência das adições ativas varia de acordo com a composição química e mineralógica das adições, da proporção desse material no cimento, e do grau de reatividade do agregado.<br>The alkali-aggregate reaction is a pathologic manifestation that can induce the premature distress and loss in serviceability of concrete structures affected. It is directly associated to the selection of materials (cement, coarse and fine aggregates, water and additives), as the interaction between these materials and environmental condition will grant the concrete some of the properties related to its service life. The slow reaction between alkali hydroxides soluble in the liquid phase within concrete pores and reactive aggregates gives rise to a gel that piles up within concrete voids and the aggregate-paste interface. In presence of water, the gel expands and exerts internal pressure in the concrete. When the internal pressure exceeds the tensile strength, cracking may come up as result. The alkali-aggregate reaction requires the action of water, reactive aggregate and alkalis altogether. Prevention can be carried out by eliminating one of these factors, i.e. employing either inert aggregates or lowalkali cements, or keeping the concrete away from moisture. Otherwise, preventive measures must be taken when reactive aggregates are used in civil construction works, such as the use of low-alkali cements or composite cements bearing alkaliaggregate- reaction mitigating admixtures: blast-furnace slag, fly ash, metakaolin and silica fume, which are the object of the present research. The experimental work included the analysis of two potentially reactive aggregates to alkali hydroxides: basalt and granite milonite. The igneous basalt carries deleterious constituents such as glass, chloropheite (cryptocrystalline silica), that will give rise to the DONDOL_VLOLFD type reaction while the metamorphic granite milonite carries micro granular, recrystallized, undulate-extinction-bearing quartz and deformed feldspar grains, that give rise to DONDOL_VLOLFDWH type reaction. Aiming at evaluating how efficient in mitigating these reactions the active admixtures are, these aggregates were mixed with 16 composite cements. The contents of admixtures followed those usually found in Brazilian industrial cements for blast-furnace slag (15%, 30%, 45%, 60%) and fly ash (10%, 15%, 25%, 35%), and those generally added directly to concrete for metakaolin (5%, 10%, 15%, 20%) and silica fume (5%, 10%, 15%). All materials were characterized for their chemical composition, physical properties and mineralogy. Petrography was carried out on the aggregates. The mortar bars were analyzed at the scanning electronic and transmitted-light optical microscopes. Mercury-intrusion porosimetry and thermal analyses were carried out to quantify residual portlandite. The alkali content within the bars was determined in order to verify migration of Na+ ions. The results show that the efficiency of active admixtures varies according to their chemical and mineralogical composition and proportioning in cement, and to the aggregate reactivity.
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Barin, Daniel Sacchet. "CARBONATAÇÃO E ABSORÇÃO CAPILAR EM CONCRETOS DE CIMENTO PORTLAND BRANCO COM ALTOS TEORES DE ADIÇÃO DE ESCÓRIA DE ALTO FORNO E ATIVADOR QUÍMICO." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/7702.
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The carbonation phenomenon, reaction between CO2 from the atmosphere in the presence of humidity with the Portland cement hydration products, induces pH reduction to levels that can cause the elimination of steel s protective layer, enabling the corrosion mechanism of the steel structure to start.. This is one of the main pathologies in the reinforced concrete and its occurrence depends on the existence of oxygen, humidity and potential difference between two different locations of the steel bar. This research analyzed the performance of different concrete mixtures produced with Portland cement with high levels of blast furnace slag, with and without the chemical activator sodium sulfate (Na2SO4), in relation to compressive strength, capillary absorption and carbonation. For comparison purposes, gray Portland
cement concrete test samples were also cast. For the white Portland cement concrete, slag contents of 0% and 50%, without and with chemical activator at concentrations of 4% and 70% were chosen. With the gray Portland cement it was produced concrete with 0% and 50% of slag addition, with and without chemical activator. For each mixture was adopted water/binder ratios of 0.30, 0.42 and 0.55. The samples cast with white Portland cement, destined to the compressive strength tests were broken at 3, 7, 28 and 91 days and the capillary absorption tests were done 91 days after molding. The samples destined to accelerated carbonation tests, cast with the two kinds of cements, were submitted to an atmosphere with 2% CO2 concentration, temperature of 23±1ºC and relative humidity of 75±2%. The carbonation depths determination was realized in the ages of 0, 3, 6, 9 and 12 weeks, after entrance in the chamber. From results obtained it was noticed that compressive
strength reduced as the slag content and water/binder ration increased. In more advanced ages, however, the difference in compressive strength between mixtures with slag and the reference mixture was smaller than in the first ages. The capillary absorption reduced with
the slag content increase, as a consequence of the refinement pores. The carbonation depth, for the white and gray concretes, increased with the slag content and the chemical activator utilization. In a comparison between white and gray Portland cement concretes, for the same
slag content and water/binder ratio, the higher carbonation depths were reached with the white concrete, and this difference was higher when the water/binder ratio was increased.<br>O fenômeno da carbonatação, reação entre o CO2 da atmosfera em presença de umidade com os produtos de hidratação do cimento Portland, provoca a redução do pH do
concreto a níveis que podem causar a eliminação da película passivadora do aço, podendo ocorrer a instalação do mecanismo de corrosão das armaduras, uma das principais
patologias em estruturas de concreto armado, desde que para isto, exista oxigênio, umidade e uma diferença de potencial entre dois pontos distintos da barra de aço. Esta pesquisa
analisou o desempenho de diferentes misturas de concretos produzidos com cimento Portland branco com altos teores de escória de alto forno, com e sem ativador químico sulfato de sódio (Na2SO4), frente à resistência à compressão, absorção capilar e carbonatação. Para efeito de comparação da resistência à carbonatação, também foram moldadas amostras com concreto de cimento Portland cinza. Para o concreto de cimento Portland branco foram adotados os teores de adição de escória de 0%, 50% sem e com ativador químico no teor de 4% e 70%. Com o cimento Portland cinza foram produzidos
concretos com 0% e 50% de adição de escória sem e com ativador químico. Para cada mistura foram adotadas três relações água/aglomerante, 0,30, 0,42 e 0,55. Os corpos-deprova, moldados com cimento Portland branco, destinados aos ensaios de resistência à compressão foram rompidos aos 3, 7, 28 e 91 dias e os ensaios de absorção capilar foram
realizados 91 dias após a moldagem. As amostras destinadas ao ensaio de carbonatação acelerada, moldadas com os dois tipos de cimento, foram submetidas a uma atmosfera com
concentração de 2% de CO2, temperatura de 23±1ºC e umidade relativa de 75±2%. A determinação da profundidade carbonatada foi realizada nas idades de 0, 3, 6, 9 e 12
semanas, após a entrada na câmara de carbonatação. Dos resultados obtidos constatou-se redução nos valores de resistência à compressão das misturas com escória com o aumento no teor de adição e da relação água/aglomerante, porém, em idades mais avançadas, a diferença entre as resistências das misturas com adição e aquelas da mistura de referência foi menor que nas primeiras idades. A absorção capilar diminuiu com o aumento no teor de adição de escória, conseqüência do refinamento dos poros. A profundidade de
carbonatação, para os concretos branco e cinza, aumentou com o aumento no teor de escória e a utilização de ativador químico. Na comparação entre os concretos de cimento
Portland branco e cinza analisados, para mesmo teor de adição e relação água/aglomerante, as maiores profundidades de carbonatação foram atingidas pelo concreto branco, e esta diferença foi maior à medida que aumentou a relação
água/aglomerante.
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LaBarca, Irene K. "Deicer scaling resistance of concrete containing slag cement." 2006. http://catalog.hathitrust.org/api/volumes/oclc/70222728.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 2006.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 108-110).
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LU, WEN-RU, and 呂文儒. "Engineering characteristics of granulated blast furnace slag-cement concrete." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/77334059348081469037.
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HUANG, TAI-CONG, and 黃泰聰. "The compressive strength of blast furance slag-cement concrete." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/67320344352533879270.
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CHEN, CI-XIAN, and 陳賜賢. "The use of slag-cement concrete in coastal engineering." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/49945884898567960834.
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Foley, Ryan David. "Strength, shrinkage, hardened air void characteristics of concrete containing slag cement." 2006. http://catalog.hathitrust.org/api/volumes/oclc/71331409.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 2006.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 95-97).
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Mason, Nicholas Robert. "Effects of ground granulated blast furnace slag in Portland cement concrete." 2003. http://catalog.hathitrust.org/api/volumes/oclc/54106741.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 2003.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 71-75).
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HUANG, ZHENG-XIAN, and 黃正憲. "Using Na2SiO3 to Activate Reduction Slag in Producing no Cement Concrete." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/v7m3xm.
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碩士<br>國立聯合大學<br>土木與防災工程學系碩士班<br>106<br>In this study, blast-furnace (BF) slag powder and reduced electric arc furnace (EAF) slag completely replaced cement as the bonding material, and its cementing properties were intensified with sodium silicate as the alkali agent. The byproducts of the steelmaking process—oxidizing slags and oxidizing slag sand—were used as the aggregate, which was mixed with the cementing material to prepare a green concrete that does not use natural materials or cement.
The research process first involved testing the basic physical and chemical properties of the BF slag powder, EAF slag, oxidizing slag sand, and oxidizing slag. The mix design adopted three differing blends of cementing material: pure cement, 100% BF slag powder, and the replacement of 20% of the BF slag powder with EAF slag. From these, three concretes with respective target compressive strengths of 140 kgf/cm2, 175 kgf/cm2, and 210 kgf/cm2 at 28 days old were designed. Tests for properties such as slump, compressive strength, mass growth, thermogravimetry (TG), autoclave expansion, and scanning electron microscopy (SEM) microstructure, after which the test results were analyzed and discussed.
The research results indicated that all groups achieved the three target compressive strengths. The group that replaced 20% of the BF slag powder with EAF slag achieved a compressive strength similar to or higher than that of the pure cement group at 7 days and 28 days old, whereas its compressive strength at 90 days old was higher than that of the cement group. In addition, using the alkali agent to activate the EAF slag effectively decreased its expansion rate, with an approximately 14% decrease in the expansion rate of the group that replaced 20% of BF slag powder with EAF slag.
The mass growth of each group yielded a growing normalized curve, indicating the occurrence of a pozzolanic reaction that filled the pores and achieved the densification effect. In addition, tests such as energy-dispersive X-ray spectroscopy (EDS), SEM, X-ray diffraction, and DTA/TG were conducted to verify that the activation of EAF slag through sodium silicate could enhance the properties of concrete. The results from the toxicity characteristic leaching procedure (TCLP) demonstrated that using EAF slag did not cause harm to the environment. Finally, the results of an economic analysis illustrated that using sodium silicate as the alkali agent was more economical than using the pure cement group because of the recognition of carbon credit.
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Lin, Yi-Shan, and 林依珊. "Using K2SiO3 to Activate Reduction Slag in Producing no Cement Concrete." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/30259337516868090487.
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Yu, Meng-Chou, and 游孟洲. "The Influence of the cement and slag powder on asphalt concrete pavement." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/51899702755955433411.
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碩士<br>國立中興大學<br>土木工程學系所<br>97<br>It is generally known that there has been an increasingly greater demand for asphalt concrete every year for newly building and maintenance of bituminous pavements. The sources of asphalt concrete stopping are rock powder or cement. However, in considering the high cost of the cement and increased shortage of crushed stones, a raw material for the rock powder, due to environmental protection and conservation, the government has been reinforcing and promoting the regeneration policy. To comply with the government policy and solve the shortage problem, slag powder produced by steel factories is strongly recommended for regeneration purpose.
This research aims to evaluate based on various testing the availability of cement or slag powder in different ratios for Marshall samples served as a filling for asphalt concrete. The testing performed includes stability, detention, idirect tensity and rutting tests.
The experimental result shows that the six testing groups with different ratios of filling have all conformed to the standard value. However, the addition of more slag powder shows higher tensile strength, whereas it shows decreased rutting test with a decrease of slag powder. As to stability test, there is no significant difference between adding cement and slag powder. The above results demonstrate that the cement group may have slightly better overall effect. However, the difference is not significant between the two groups of filling.
Therefore, in considering the economic cost, slag powder - resource of recycling material- may still serve as a good source of a filling for bituminous pavement.
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Tan, Siao-Cih, and 譚筱慈. "The Proportion of Defulsurization/Granulated Slag Recovery on the Concrete Without Portland Cement." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/34382375966220541653.
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碩士<br>國立高雄應用科技大學<br>土木工程與防災科技研究所<br>97<br>Desulfurization slag in the Chinese Steel Company has high pH value and can offer the alkaline environment, promote the hydration rate of slag. It makes concrete without portland cement it in order to use the desulphurization slag to apply to civil construction in a large amount.This research makes cement with slag and desulphurization slag, attempt to add super plasticizer, fly ash and natural coarse aggregate in order to promote the intensity of concrete.Carry on different material tests specifically with powder and aggregate while studying. The powder tests include the specific gravity, specific surface area, micro-structure and properties analyses. Part of the aggregate carries on specific gravity and sieve analyzing. The concrete is by making the volume of the required slump up to 150 mm and also the required compressive strength up to 140kg/cm2. The relationship between component, microstructure and performance was also investigated.
Result of study show, add super plasticizer can improve concrete work degree greatly, add super plasticizer to 0.8% is it adjust water consumption is it collapse degree is it between 150~550 mm, and improve the intensity of concrete indirectly to fall to make to need. super plasticizer is the weight of 0.8% and granulated slag is that 550 kg/m3 makes can be higher than 140 kg/cm2, the low intensity concrete while belonging to.
It is still quite limited to the effect which improves the intensity of concrete to add fly ash and natural coarse aggregate, but have sizable influence to mix nature on the concrete newly.
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Chang, Tung-Yuan, and 張東源. "Compression Properties of Slag Cement Concrete Made by the Dry- Mix/Steam-Injection Procedure." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/27183615093099781434.
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Rao, Ming-Kang, and 饒明康. "Engineering properties of concrete made of the mixture of cement and MSWI mixed ash slag." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/13267755311718234550.
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碩士<br>國立聯合大學<br>土木與防災工程學系碩士班<br>96<br>How to treat the municipal solid waste has been a worldwide problem. In Taiwan the municipal solid waste was mainly burned to ash with incinerator, but the MSWI fly and scrubber ash contained large amount of heavy metals, which need to be treated to become harmless and recycled as useful resources. First, we try to mix fly-ash and scrubber-ash uniformly with the weight ratio of 1:3, the production ratio of the incinerator, and the waste glass powder was added to adjust the mix-ash basicity S (S = CaO/SiO2) from 0.8 to 1.2, and melted into slag and pulverized to powder with particle size less than Sleeve No.400 (38�慆). The pulverized slag powder was used to replace 20 wt.�s of cement for molding 5cm�e5cm�e5cm slag-blended cement mortar specimen for compressive strength test, the test result show that the compressive strengths of slag cement mortar specimens were weaker than those of plain cement mortar specimens before 28-day curing age, but those with curing ages of 60-day to 90-day were stronger than plain cement mortar specimen. Second, we selected slag powder with basicity S = 1.1 to replace 0�{40 wt.�s cement, and molded 5cm�e5cm�e5cm specimens for compressive strength test. The result revealed similar phenomenon, and the strengths of all specimens with 90-day curing age were still stronger than that of plain cement mortar specimen even the slag powder replacement was up to 40 wt.�s.
According to the good results of strength for slag cement mortar, we use the modified slag powder with basicitys S = 1.1 to replace 20 wt.�s cement and select three kinds of water to binder ratios (W/B = 0.68, 0.58 and 0.48) for molding slag cement concrete cylinder (10cmψ�e20cm H) specimens. Then they were under compressive strength test, stress-strain measurement, expansion measurement and durability test. The results revealed those the strength of the slag cement concrete specimens was weaker than that of plain cement concrete specimen at the early curing age, but they were similar at age of 28-day, and were stronger than those of plain cement concrete specimens with curing ages of 60-day, 90-day and 180-day. It seems like Pozzolanic reaction.
As aforementioned, the test results revealed that the modified MSWI mix-ash slag powder for partial cement replacement for concrete engineering is feasible in practical application. The treated fly and scrubber ashes are harmless and can be recycling as a resource and are good for sustainable environment of earth.
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Ma, Daniel, and 馬丹尼. "Strength Prediction and Property Analysis of Concrete with Slag and Fly Ash as Cement Replacements." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/03535601003723547398.
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碩士<br>國立臺灣大學<br>土木工程學研究所<br>100<br>Due to the energy consumption of producing cement, the alternative use of industrial byproducts in concrete are beneficial to a country’s economy and reduces environmental pollution. The use of slag or fly ash to replace Portland cement will both yield favorable results such as better workability without water reducing agents, a higher strength at old age and low water hydration heat. The construction industry is now focusing on the ternary use of slag, fly ash and cement as the basis of cement mixture, therefore a prediction model is needed to accurately calculate its compressive strength is of great importance.
This study aims to predict the compressive strength of concrete with the ternary use of slag, fly ash and cement, with only the k values of slag and fly ash as the foundation. Four water to binder ratios (w/b) were selected for this experiment (0.35, 0.45, 0.55, 0.65), each ratio having slag plus fly ash replacement levels of 0%, 30%, 40%, 50% respectively, with a 7 to 3 ratio between slag and fly ash. Data is then collected and two models are proposed concerning the ternary blends of slag, fly ash and Portland cement.
The results show that it is feasible to superposition the separate k values of slag and fly ash to predict the compressive strength of ternary mixtures.
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Shiu, ruei-Wen，, and 許瑞紋. "Using Rapid Chloride Migration to Determine Chloride Permeability of the Slag and Blended Cement Concrete." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/954uyh.
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碩士<br>國立臺灣海洋大學<br>材料工程研究所<br>107<br>To explore the difference of different binder, the test samples are divided into OPC, Slag concrete and blended cement IS, IP. The water-binder ratio (W/C) was 0.35, 0.45, 0.55 and 0.65, respectively. Processed RCM test after 28 and 91 days in curing age. The concrete durability test is a majority for testing the resistance of concrete to chloride penetration. The categories of the test are the original natural diffusion of ions and the use of electric fields to accelerate ion transport. Considering the disadvantages of natural diffusion and RCPT's Joule effect, RCM was used as the main test of this study.
Due to the colorimetric method in RCM measuring the penetration depth of chloride ions, there are many variables that lead to depth misjudgment. It is necessary to establish the most suitable colorimetric method of variation as its reference value, set the minimum coefficient of variation as the most stable depth sampling method, and further calculate the colorimetric non-steady-state migration coefficient. In order to establish that the unsteady transmission coefficient of the colorimetric method is consistent with the actual chloride ion distribution curve, use the milling method non-steady-state migration coefficient, the initial current and the colorimetric non-steady-state migration coefficient to compares its linear relationship.
Because NT Build 492does not specify the depth measurement method and steps after the test, and there are many defects, such as：silver nitrate(AgNO3) usage, surface chloride instability and ratio the color method and the color change of sliver nitrate corresponding to the color method and the milling method are future determined in this study.
The experimental results show that the most suitable amount of silver nitrate is 3 ml; using the 9-point average method to measure the colorimetric depth is time-saving and accurate. In the relationship of cement：general concrete has the largest unsteady transmission coefficient regardless of curing age; concrete added with hearthstone is completely reactive at 28 days of age and therefore non-steady-state migration coefficient is not related to the amount of somewhat unstable, the other water-to-binder ratio decreases with the increase of the substitution amount; and the blended cement IS and the slag substitution of 30% has similar results, and IP has a very low non-steady-state migration coefficient.
The comprehensive analysis shows that the relationship between the initial current and the non-steady state migration coefficient of the colorimetric method has a high relationship in linear relationship, the coefficient of determination is as high as 0.9 or more. The transmission coefficient is slightly lower than the age of 91 days as at 28 days of age, but the relationship between the two is not much different.
In terms of the average angle, the coefficient of determination is about 0.9; surface chloride ion is not defined as a fixed value for its specification, but on average is about 0.56; and the concentration of the colorimetric color boundary is not value 0.07N as specified in the specification. The value of colorimetric color boundary is very wide and has nothing to do with the binder. Therefore, this study considers that the number of colorimetric non-steady-state migration coefficients can be an evaluation method of durability, but the color change of silver nitrate still needs more experiments to evidence.
Key words：RCM、depth measurement、colorimetric method、non-steady-state migration coefficients
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Lin, Cyun-Syuan, and 林群軒. "Study on Air-cooled Blast Furnace Slag Used for Pervious Concrete of Low Cement Amount." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/94544501454923624453.
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碩士<br>國立屏東科技大學<br>土木工程系所<br>103<br>The thesis used the air-cooled blast furnace (ABF) slag by China Steel Corporation (CSC) as aggregate and added the inorganic ion curing agent by Johnson Corporation in the making of pervious concrete. The water-cement ratios W/C of pervious concrete specimens ranged from 0.62 to 0.76. Aggregate particle size was between 4.75~19.0 mm. Cement amount C in the mix is 150 kg. Tamping tools were two steel rods, one with 5 cm diameter round bottom, 2 cm thickness, and the other with 5#westeur024#5 cm square bottom, 2 cm thickness, were used to impact cylindrical and beam specimens respectively. The specimens were made by the same degree of impacting, and were performed the compressive strength, flexural strength, permeability coefficient, and porosity tests. The purpose of the tests is to find the W/C of maximum strength for the concrete, which also have to meet the permeability and water retention requirements.
Test results showed that, both the W/C of the maximum strength of 28 day concrete were 0.72. The values of the compressive strength fc and modulus of rupture R were 41.3 kgf/cm2 and 16.3 kgf/cm2 respectively. Compared with the values 171 kgf/cm2 and R=41.1 kgf/cm2 of C=350 kg, the strengths were its 0.24 and 0.4 time. The mix for this specific W/C was 167 kg cement, 75.2 kg water, 1.7 kg curing agent and 1484 kg slag aggregate. The ratio of the 7 day to 28 day compressive strength fc7/fc28 were between 0.63~1.09, averaged at 0.87. The ratio of modulus of rupture Rc7/Rc28 were between 0.63~1.23, averaged at 0.99, higher than 0.70 of normal concrete or 0.85 and 0.92 of C=350 kg concrete. The ratio of the 28 day compressive strength to modulus of rupture R/fc were between 0.26~0.40, averaged at 0.31, higher than 0.15 of normal concrete or 0.22 of C=350 kg concrete. All the permeability coefficient k values exceeded 2.3 cm/sec, far beyond the criteria value 0.01 cm/sec proposed by Taiwan Architecture and Building Center. The porosity n values ranged between 37%~45%, were also larger than the criteria value 15%.
The strengths fc＝41.3 kgf/cm2 and R＝16.3 kgf/cm2 of the tested C=150kg ABF slag previous concrete can be used in class B pavement proposed by Taiwan Architecture and Building Center for load layer of 6 cm depth, and can be used in class A pavement for load layer of 10 cm depth.
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Wu, Yi-Xiang, and 吳逸翔. "Engineering properties of concrete made of the mixture of cement and MSWI fly ash slag." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/47602187366923675953.
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碩士<br>國立聯合大學<br>防災科技研究所<br>95<br>How to treat the Municipal solid waste was a difficulty problem of modern civilization, because being damage to the earth sustainable development. At present, incineration is still a suitable way of problem-solving for municipal solid wastes. But MSWI fly-ash contained large quantity of heavy metal harmful to mankind. It need to be recycled as useful resources.
In this study, municipal solid waste incinerator (MSWI)fly ash was melted into slag ,the slag was then pulverized to powder with sized less than #400 sleeve (38um)for experimental study, slag– cement mortar specimens were molded by 0~40% cement replacement with slag powder. The results revealed that the 90-day compressive strength of the 20% cement replacement specimen was the best.The pulverized slag was used to substitute 20 wt % of cement for molding slag-blended concrete cylinder specimen. Compressive strength of specimens of various ages were compared with those of control specimens(plain cement concrete).The results revealed that the compressive strength of 20 wt % slag-blended cement concrete was below that of control group in the early stage. However, the compressive strength were 109% and 120% of those of control group for ages of 60 days and 90days, respectively. The results of porosity (MIP) analyses showed that the average pore sizes of the 60-day and 90-day spEcimens were both smaller than that of 28-day specimen. This is the evidence that all the slag-blended specimens exhibited a pozzolanic reaction. This decreased tendency of pore sized is in accordance with that of the increased compressive strengths of the specimens. The slumps (workability) and setting times of both the slag-blended and control group specimens were similar. The results of this study revealed that MSWI slag-blended cement concrete is feasible for practical application.
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TSAI, CHUN-MI, and 蔡純宓. "Performance Study of the Porous Cement Asphalt Concrete Pavement with the Precoating Basic Oxygen Furnace Slag." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/16768572799003512869.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>營建工程系<br>102<br>This study used slag powder mixing cement into paste and pre-coating basic oxygen furnace slag became to aggregate. This study estimated the feasibility of SPB use in porous cement asphalt concrete pavement and investigating the aggregate characteristic of starched aggregates.
This Research using Type-Ⅲ modified asphalt making specimens as a bonding material and then following four stages to judge experiment result. The first stage, estimating differences of properties between BOFS and starched aggregates, for assess effects of aggregate characteristic after BOFS being starched. The 2nd stage, investigating Type-Ⅲ modified asphalt physical character and the proportioning and physical properties of cement asphalt paste. The 3rd stage, starched aggregate respectively, 25%, 50% and 75% to replace coarse aggregates and mixed with Type-Ⅲ modified asphalt being into conventional porous hot-mix asphalt concrete as a control group, and using cement asphalt paste mixed porous cement-asphalt concrete as a comparison group. The 4th stage, processing among of experiments contented with asphalt concrete mechanical properties of porous cement, Pavement performance, durability performance, acoustic characteristics of the test about with both traditional hot mixing porous asphalt concrete and cold mixing porous cement asphalt concrete, and compare the results to assess the feasibility of the starched aggregates used into porous cement asphalt concrete pavement.
Research results show that in starched aggregates properties from BOFS containing unreacted completely free lime, so after water absorption expansion will happen, by being aggregates starched sealed, prevent moisture infiltration, can inhibit BOFS possibilities of future expansion and improvement of converter in BOFS's surface physical properties.
In terms of cement asphalt paste, this study uses of cement asphalt paste ratio of C/A=1.1, FSP=5% and asphalt emulsion residue 60%, whose W/C =0.41 reaching cement required for complete hydration of W/C=0.42, Test results of cement asphalt paste slump flow value of up to 32cm, 28day strength can reach 89kgf/cm2, so use this ratio as the selection of cement asphalt paste Proportioning.
Starched aggregate application about porous asphalt concrete cement, Comprehensive test results show that although the PCAC groups the test results are better than PAC groups, PCAC group, the attrition rate is out of specification,PCAC group in terms of resilient strength indices in starched aggregates replace natural aggregates 75% below specifications. So starched aggregate is used to replace the natural coarse aggregate 50% processed testing with 7, 14, and 28 days ages. Test result shows the mechanical properties, pavement performance, durability performance and acoustic characteristics are better than the PAC group but should beware of high attrition rates.
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Chang, Shu-chia, and 張書嘉. "Study of the Stone Matrix Cement Asphalt Concrete Pavement with the Precoated Basic Oxygen Furnace Slag." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/47154055168686388539.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>營建工程系<br>101<br>The study used Basic Oxygen Furnace Slag wrapped with blast furnace slag grout, referred as SPB. In addition to the physical properties of SPB, the effects of SPB applied on the pavement made of Stone Matrix Cement Asphalt concrete were also explored. In the first stage of this study, the different physical properties between Basic Oxygen Furnace Slag (B) and SPB were explored. The ratio of Cement Asphalt Paste, CAP, and its physical properties were explored the second stage. The third stage took SPB, which replaced parts of natural coarse granular materials, to be hot mixed with modified asphalt III, MA3, becoming Stone Matrix Asphalt (SMA), as control group and to be cold mixed with Cement Asphalt Paste, CAP, becoming Stone Matrix Cement Asphalt Concrete, SMCAC, as the experimental group. SMA and SMCAC were compared with tests in terms of mechanical properties, pavement performance, durability properties, and acoustic characteristics to evaluate the effects of SPB applied on SMCAC.
The study results showed that SPB has the function to fill the pores on the surface of Basic Oxygen Furnace Slag for that it attaches with a layer of blast furnace slag grout, which can reduce the swelling and improve various physical properties of Basic Oxygen Furnace Slag. In terms of Cement Asphalt Paste, according to the results of considering both new mixed properties of CAP and mechanical properties, the best ratio of CAP is C/A = 1.2 (cement/asphalt) and FSP/A = 4% (surfactant/asphalt). In terms of SPB applied on SMCAC, from the combining evaluations by test results for mechanical properties, pavement performance, durability properties, and acoustic characteristics, we learned that the higher SPB substitution of natural coarse granular materials, the better quality of SMCAC obtains. On the whole, the SMCAC containing SPB has excellent effects and can achieve the purpose of energy saving and waste reduction.
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CHENG-CHUN, O. LEE, and 歐李正君. "Performance Study of the Dense Graded Cement Asphalt Concrete Pavement with the Precoating Basic Oxygen Furnace Slag." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/14926460873795244584.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>營建工程系<br>102<br>This study used slag powder mixing cement into paste and pre-coating BOFS (called SPB or starched aggregates ) became to aggregate. This study estimated the feasibility of SPB use in the dense gradation cement-asphalt concrete pavement and investigating the aggregate characteristic of starched aggregates. The experiment result of study was discusses with the four states. The first stage, estimating differences of properties between BOFS and starched aggregates, for assess effects of aggregate characteristic after BOFS being starched. The 2nd stage, investigating Type-Ⅲ modified asphalt physical character and the proportioning and physical properties of cement asphalt paste (CAP). The 3rd stage, starched aggregate respectively, 25%, 50% and 75% to replace coarse aggregates and mixed with Type-Ⅲ modified asphalt being into conventional hot mix dense gradation of asphalt concrete (DGAC) as a control group, and using cement asphalt paste mixed dense gradation asphalt cement concrete (DGCAC) as a comparison group. The 4th stage, processing among of experiments contented with asphalt concrete mechanical properties, Pavement performance, durability performance, acoustic characteristics of the test about with both traditional hot mixing dense gradation asphalt concrete and cold mixing dense gradation cement asphalt concrete, and compare the results to assess the feasibility of the starched aggregates used into dense gradation cement asphalt concrete pavement.
Research results show that in starched aggregates properties from BOFS containing unreacted completely free lime, so after water absorption expansion will happen, by being aggregates starched sealed, prevent moisture infiltration, can inhibit BOFS possibilities of future expansion and improvement of converter in BOFS's surface physical properties.
In terms of cement asphalt paste, this study uses of cement asphalt paste ratio of C/A=1.1, FSP=5% and asphalt emulsion residue 60%, whose W/C =0.41 reaching cement required for complete hydration of W/C=0.42, Test results of cement asphalt paste slump flow value of up to 32cm, 28day strength can reach 89kgf/cm2.
Starched aggregate application about dense gradation Cement asphalt concrete. Comprehensive test results show that the DGCAC group test results are in compliance with the specifications, and are mostly better than the DGAC group. DGCAC group, the attrition rate is slightly larger than the DGAC groups. DGCAC groups appear in the Marshall and indirect tension test results, in starched aggregates replace natural aggregates 25%, strength did best. So starched aggregate is used to replace the natural coarse aggregate 25% processed testing with 7, 14, and 28 days ages. Test result shows the mechanical properties, pavement performance, durability performance and acoustic characteristics are better than DCAC group.
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Chen, Jin, and 陳俊欽. "Effects of Partial Replacement of Cement by Slag on the Rheological Property and Workability of Flowable Concrete." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/44497295105654456691.
Full textAbstract:
碩士<br>國立中興大學<br>土木工程學系<br>90<br>Pozzolanic materials are often added into the process of high performance concrete (HPC). Slag is a by-product of iron-smelting in the blast furnace, and has stable chemical components and pozzolanic properties. This research intends to investigate the effect of slag on the flowability of flowable concrete.The water-binder ratio of concrete was slected as 0.4,0.5 and 0.6. The substitute ratio of slag in cement was the only variable, and designed to be 0, 10, 20, 30, 40 and 60%. By experiment the rheology test was adopted as major method to determine the workability of fresh concrete, while the slump test, V-funnel test, L-funnel test, were also conducted for comparison.
Test results show that the effects of slag on workability are different for concrete with different water-cementitious ratio. The concrete of higher water-binder ratio can content more water that provide all components of concrete sufficient water for smoothening, while the slag will enhance the proper viscosities in concrete thus produce positive assist for the workability of concrete. The concrete containing more slag for lower water-binder ratio will make the paste more adhesive, where Free water will not be sufficient to smoothen the surface of aggregate in concrete. This results in a concrete too dry and unflowable. As to the substitute ratio of slag, it is recommended to be 30% for concrete with 0.4 water-binder ratio, and 20% for concrete with water-binder ratio of 0.5 and 0.6 respectitively.
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Kyalika, Cynthia Mumeka. "Impact of curing methods on the strength of copper slag concrete." Diss., 2019. http://hdl.handle.net/10500/26694.
Full textAbstract:
The eco-friendly alternatives use is increasing momentum in a conscious effort
towards sustainability. In this regards, the relevance and the economic value of
using copper slag as a concrete aggregate are explored in this study in order to
contribute towards metallurgical waste recycling. Emphasis is placed on the
evaluation of the concretes strengthening prepared with copper slag contents and
produced under four curing methods: water immersion, water spraying, plastic
sheet covering and air-drying. In each curing case excluding for water immersion,
was duplicated in indoors (i.e. in the laboratory) and outdoor exposure (so was
prone to varying environmental conditions). This was specifically aimed at
capturing the effects of tropical weather conditions typical of the Lualaba province
in the Democratic Republic of Congo.
The control mix was designed to reach 25 MPa of compressive strength. Copper
slag was successively incorporated as sand replacement at the following mass
fractions: 20 %, 40 % and 60 %. Freshly mixed concrete samples were evaluated
for workability. Cube specimens were cast accordingly, cured for 28 days and then
tested for density and compressive strength.
Results indicated an increase in strength up to 20 % of replacement rate for all the
curing methods. Further additions resulted in reduction in the strength, but the rate
of reduction depended on curing conditions. The increase in strength was mainly
credited to the physical properties of copper slag that could have contributed to the
cohesion of the concrete matrix. It has been found that appropriate ways of curing
can still achieve greater results than that of the control mix since 80 % of humidity
is ensure. The two-way ANOVA test performed on the 28-days compressive
strength values confirmed the significant influence of the curing methods, of copper
slag content and the interaction between them. It has been found that considerable
influence is attributed to copper slag content and that warm environmental
conditions further extend the concrete strengthening.<br>College of Engineering, Science and Technology<br>M. Tech. (Chemical Engineering)
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Huang, Shih-feng, and 黃士峯. "A Study on the Cool Surface Properties of Fly Ash and Slag Cement Concrete with Different Mix Proportions." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/48757093977027435573.
Full textAbstract:
碩士<br>義守大學<br>土木與生態工程學系碩士班<br>98<br>The intensive buildings, road pavements, and other man-made facilities in urban area which absorb the massive short wave radiation and the anthropogenic heat discharge of traffic and air conditioning cause the temperature-increasing phenomenon of the urban heat island effect. The effect of urban heat island will increase the summer air conditioning energy consumption, and accelerate the photochemical reaction to have higher ozone concentration that is harmful to human health and increase the burden of the social costs at medical insurance. Therefore, United States, Japan, and many countries in Europe have already taken actions to improve the problems of energy, health and environment which is caused by the urban heat island effect in recent years.
There are mainly two kinds of the cool technologies, cool pavement and cool roof, which are applied to improve the man-made pavements and the building shells. These technologies used in raising the Albedo in the road pavements and the roofs to reduce the solar radiation absorption, is the key objective in researches of urban heat island mitigation. The cool technology can be classified according to the materials: cool cement concretes, cool asphalt concretes, cool coatings and other cool material technologies.
This research project is aimed at the investigation on the cool cement concretes and discusses the effect of the different Albedo in concrete composition material on the Albedo of concrete and the inter-relationship between Albedo of concrete, grey scale value, and surface temperature through the different types of concrete mortar specimens which adding varied compositions of fly ash or blast furnace slag powder.
The result of the investigation shows that replacing of the Portland cement by white cement or blast furnace slag powder can both promote the Albedo. The research project also developed the relation between composition material and the concrete Albedo along with the optimal gray scale transformation formula, which can promptly extrapolates the Albedo. In the last section we will discuss the cost evaluation and the benefit assessment of cool cement concretes and provide some suggestions on the Taiwan’s future application as well as the research and development of cool technology. It is hoped that this research can contribute the urban heat island mitigation in Taiwan.
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chen, shen-chou, and 陳信州. "The Research of Leveling the Early Strength of Blending of Granulated Blast Furnace Slag with Portland Cement Concrete." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/92479893690771817454.
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Zeng, Yi-Lin, and 曾伊麟. "Performance Evaluation On Porous Asphalt Concrete Mixed with Polymer-Modified Cement between Crushed Stone and Basic Oxygen Furnance Slag." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/38629120928596678509.
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