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Zach, J., J. Bubeník, and M. Sedlmajer. "Development of lightweight structural concrete with the use of aggregates based on foam glass." IOP Conference Series: Materials Science and Engineering 1205, no. 1 (November 1, 2021): 012014. http://dx.doi.org/10.1088/1757-899x/1205/1/012014.
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Abstract Lightweight concretes are increasingly being used in the construction industry, either for the overall lightweighting of the structure itself, reducing material consumption for construction and thus CO2 emissions, or for specific reasons such as improving the thermal insulation properties of the structure or acoustic properties. Today, lightweight concretes with lightweight expanded aggregates (expanded clay, agloporite) are most commonly used. This paper deals with the production of lightweight concretes lightweighted with foamed glass-based aggregates. Foamed glass is a lightweight material characterised by a very good ratio of thermal insulation and mechanical properties. Foamed glass is made of approximately 90% recycled glass waste (mostly mixed), which cannot be used in any other way, as well as water glass and glycerine. When concrete is lightened with foamed glass, these concretes achieve unique properties while conserving primary aggregate resources, avoiding landfilling of glass waste and efficiently using the waste material to produce lightweight concrete with higher added value. The paper discusses the possibilities of developing lightweight structural concretes using glass foam-based aggregates to achieve higher strength classes while reducing the weight and thermal conductivity of the concrete. As part of the research work, new types of lightweight concrete with a bulk density in the range of 1750–1930 kg/m3 and a thermal conductivity from 0.699 to 0.950 W/(m·K) were developed.
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Křížová, Klára, Jan Bubeník, and Martin Sedlmajer. "Use of Lightweight Sintered Fly Ash Aggregates in Concrete at High Temperatures." Buildings 12, no. 12 (November 29, 2022): 2090. http://dx.doi.org/10.3390/buildings12122090.
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This study addresses the issue of the resistance to high temperatures of lightweight concrete lightweighted with sintered fly ash aggregate. Lightweight concretes with different amounts of lightweighting and their properties after loading temperatures of 600, 800 and 1000 °C were investigated. In particular, the effect of high temperature on the mechanical properties of the concrete was determined on the test specimens, and the effect on the microstructure was investigated by X-ray diffraction analysis and scanning electron microscopy. It was found that there is an increase in compressive strength between 0 and 21% up to 800 °C, where the increase in strength decreases with increasing degree of lightening. At 1000 °C, the internal structure of the lightweight concrete destabilized, and the compressive strength decreased in the range of 51–65%. After loading at 1000 °C, the scanning electron microscope showed the formation of spherical-shaped neoplasms, which significantly reduced the internal integrity of the cement matrix in the lightweight concrete due to the increase in their volume. It was found that the lightweight concretes with higher lightweighting showed significantly less degradation due to higher temperature.
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Paskachev, A. B., T. G. Rzhevskaya, S. A. Stel'makh, E. M. Shcherban, L. D. Mailyan, and A. L. Mailyan. "Comparison of the effectiveness of microsilica modification of lightweight concretes with coarse aggregates from various rocks." Izvestiya vuzov. Investitsii. Stroitelstvo. Nedvizhimost 14, no. 1 (April 5, 2024): 82–95. http://dx.doi.org/10.21285/2227-2917-2024-1-82-95.
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A promising line of research in construction science and practice is the creation of lightweight concretes. They exhibit the so-called strength-density ratio, i. e. a relative characteristic between the strength and weight of the resulting concrete. This ratio simultaneously reflects the maximum possible weight reduction of the structure and its operational reliability. The research aims to compare the effectiveness of microsilica modification of lightweight concretes produced with coarse aggregates from various rocks. The study analyzed the existing scientific literature on lightweight concretes, their formulations, technology, and scientific validity, as well as the structural compatibility of the components used. A comparison was made of the effectiveness of lightweight concrete modification for various formulation technological parameters. The strength of modified lightweight concrete and its strengthdensity ratio changed significantly compared to unmodified lightweight concrete. The strongest effect is achieved when using lightweight granite concrete modified with 9 % of microsilica. As a result, the maximum compressive strength was 55.9 MPa, and the strength-density ratio was 24.3•10-3 MPa•m3/kg compared to other studied concrete compositions. The increase in compressive strength was 17.2 % compared to unmodified lightweight concrete. The strength-density ratio increased by 19.1 % compared to unmodified coarse dense aggregate concrete.
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Upasiri, Irindu, Chaminda Konthesingha, Anura Nanayakkara, Keerthan Poologanathan, Brabha Nagaratnam, and Gatheeshgar Perampalam. "Evaluation of fire performance of lightweight concrete wall panels using finite element analysis." Journal of Structural Fire Engineering 12, no. 3 (July 14, 2021): 328–62. http://dx.doi.org/10.1108/jsfe-10-2020-0030.
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Purpose In this study, the insulation fire ratings of lightweight foamed concrete, autoclaved aerated concrete and lightweight aggregate concrete were investigated using finite element modelling. Design/methodology/approach Lightweight aggregate concrete containing various aggregate types, i.e. expanded slag, pumice, expanded clay and expanded shale were studied under standard fire and hydro–carbon fire situations using validated finite element models. Results were used to derive empirical equations for determining the insulation fire ratings of lightweight concrete wall panels. Findings It was observed that autoclaved aerated concrete and foamed lightweight concrete have better insulation fire ratings compared with lightweight aggregate concrete. Depending on the insulation fire rating requirement of 15%–30% of material saving could be achieved when lightweight aggregate concrete wall panels are replaced with the autoclaved aerated or foamed concrete wall panels. Lightweight aggregate concrete fire performance depends on the type of lightweight aggregate. Lightweight concrete with pumice aggregate showed better fire performance among the normal lightweight aggregate concretes. Material saving of 9%–14% could be obtained when pumice aggregate is used as the lightweight aggregate material. Hydrocarbon fire has shown aggressive effect during the first two hours of fire exposure; hence, wall panels with lesser thickness were adversely affected. Originality/value Finding of this study could be used to determine the optimum lightweight concrete wall type and the optimum thickness requirement of the wall panels for a required application.
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Wongkvanklom, Athika, Patcharapol Posi, Banlang Khotsopha, Chetsada Ketmala, Natdanai Pluemsud, Surasit Lertnimoolchai, and Prinya Chindaprasirt. "Structural Lightweight Concrete Containing Recycled Lightweight Concrete Aggregate." KSCE Journal of Civil Engineering 22, no. 8 (November 15, 2017): 3077–84. http://dx.doi.org/10.1007/s12205-017-0612-z.
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Sedlmajer, Martin, Jiří Zach, and Jan Bubeník. "USING SECONDARY RAW MATERIALS IN LIGHTWEIGHT OPEN-STRUCTURE CONCRETE WITH GOOD UTILITY PROPERTIES." Acta Polytechnica CTU Proceedings 22 (July 25, 2019): 94–98. http://dx.doi.org/10.14311/app.2019.22.0094.
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The paper presents the results of research in lightweight concrete with open structure made using a lightweight porous foam-glass aggregate produced from recycled glass powder. The goal was to develop lightweight concrete. In order to achieve the best possible properties while reducing binder content, the concrete was reinforced with by-product fibres, which helped reduce the weight of the concrete while delivering satisfactory mechanical properties. In the paper are proposed lightweight concrete with open structure made using foam-glass aggregate. Mechanical, thermal-insulating and acoustic properties were determined on lightweight concrete. Designed concrete is only made of crushed lightweight foam-glass aggregate with a combination of Portland cement with the option of adding recycled PET fibres. The new concretes possess a very good ratio of thermal insulation to mechanical properties as well as good sound absorption.
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Thienel, Karl-Christian, Timo Haller, and Nancy Beuntner. "Lightweight Concrete—From Basics to Innovations." Materials 13, no. 5 (March 3, 2020): 1120. http://dx.doi.org/10.3390/ma13051120.
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Lightweight concrete has a history of more than two-thousand years and its technical development is still proceeding. This review starts with a retrospective that gives an idea of the wide range of applications covered by lightweight concrete during the last century. Although lightweight concrete is well known and has proven its technical potential in a wide range of applications over the past decades, there are still hesitations and uncertainties in practice. For that reason, lightweight aggregate properties and the various types of lightweight concrete are discussed in detail with a special focus on current standards. The review is based on a background of 25 years of practical and theoretical experience in this field. One of the main challenges in designing lightweight concrete is to adapt most of design, production and execution rules since they often deviate from normal weight concrete. Therefore, aspects are highlighted that often are the cause of misunderstandings, such as nomenclature or the informational value of certain tests. Frequently occurring problems regarding the mix design and production of lightweight concrete are addressed and the unintended consequences are described. A critical view is provided on some information given in existing European concrete standards regarding the mechanical properties of structural lightweight concrete. Finally, the latest stage of development of very light lightweight concretes is presented. Infra-lightweight concrete is introduced as an innovative approach for further extending the range of applications of lightweight concrete by providing background knowledge and experiences from case records.
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Szafraniec, Małgorzata, and Danuta Barnat-Hunek. "Evaluation of the contact angle and wettability of hydrophobised lightweight concrete with sawdust." Budownictwo i Architektura 19, no. 2 (June 30, 2020): 019–32. http://dx.doi.org/10.35784/bud-arch.1644.
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The aim of the research presented in the paper was to evaluate the feasibility of using hydrophobic preparations based on organosilicon compounds for protection treatment on the lightweight concrete modified with sawdust. The experimental part of the work concerns the physical and mechanical properties of lightweight concrete and the influence of two hydrophobic agents on the contact angle of the material. Lightweight concrete contact angle (θw) was determined as a time function using one measuring liquid. Water repellent coatings in lightweight concrete structure with the coarse aggregate sawdust (CASD) using electron microscopy were presented. The effectiveness of hydrophobisation of porous lightweight concretes was determined on the basis of the research. For the hydrophobic surface, the contact angle decreased and it depended on the used agents. The lowest contact angle of 40.2° (t=0) was obtained for reference concrete before hydrophobisation and 112.2° after hydrophobisation with a methyl-silicone resin based on organic solvent. The results of scientific research confirm the possibility to produce lightweight concretes modified with CASD with adequate surface protection against external moisture.
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Barnat-Hunek, Danuta, Piotr Smarzewski, Grzegorz Łagód, and Zbigniew Suchorab. "Evaluation of the Contact Angle of Hydrophobised Lightweight-Aggregate Concrete with Sewage Sludge." Ecological Chemistry and Engineering S 22, no. 4 (December 1, 2015): 625–35. http://dx.doi.org/10.1515/eces-2015-0037.
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Abstract The aim of the research presented in the paper was to evaluate the feasibility of using hydrophobic preparations based on organosilicon compounds for protection treatment of lightweight aggregates modified with municipal sewage sludge. Issues related to the wettability of the surface layer of hydrophobised lightweight-aggregate concrete supplemented with sewage sludge are discussed in the paper. The experimental part of the study is focused on the physical and mechanical characteristics of lightweight-aggregate concrete and the effect of two hydrophobic preparations on the contact angle of the material. The contact angle for lightweight concrete (θw) was determined as a function of time using one measurement liquid. The hydrophobic coatings in the structure of lightweight concrete modified with sewage sludge were shown using electron microscopy. The investigations demonstrated the effectiveness of hydrophobisation of porous lightweight concretes. On the hydrophobic surfaces, the contact angles decreased with time and depended on the preparations used. The results of the research confirm the possibility to produce lightweight aggregate-concretes modified with sewage sludge with appropriate surface protection against external moisture.
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Kadlec, Jaroslav, Ivailo Terzijski, František Girgle, and Lukáš Zvolánek. "Effect of Lightweight Concrete Density on Bond Strength." Advanced Materials Research 1106 (June 2015): 33–36. http://dx.doi.org/10.4028/www.scientific.net/amr.1106.33.
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The main objective of this paper is connected with the search of an optimal anchorage length of reinforcement in lightweight and ultra-lightweight concretes. Experimentally obtained values of the bond stress between lightweight concrete and reinforcing bars are presented. The density classes of lightweight concrete were D1,0, D1,2 and D1,4. The results are compared with equal ones of normal density concrete. The tests with ordinary reinforcement and with non-metallic hybrid reinforcement C-GFPR (30% portion of carbon fibres) were conducted.
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Chernil'nik, A., V. Smachney, D. El'shaeva, Y. Zherebtsov, and N. Dotsenko. "INFLUENCE OF THE TYPE OF FIBERS USED ON THE STRENGTH AND DEFORMATION OF DISPERSED-REINFORCED LIGHTWEIGHT CONCRETE." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 7, no. 2 (February 14, 2022): 20–29. http://dx.doi.org/10.34031/2071-7318-2021-7-2-20-29.
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Fiber-reinforced concretes with improved strength and deformation characteristics are widely used in construction. The research is aimed to study the stress-strain condition of lightweight fiber-reinforced concrete, to plot stress-strain diagrams and analyze them. In total, four series of prism specimens are manufactured and tested. The first series is the control composition of lightweight concrete; the second series is lightweight concrete with a basalt fiber content of 3%; the third series is lightweight concrete with a glass fiber content of 3 %; the fourth series is lightweight concrete with a basalt fiber content of 1.5 % and 1.5 % glass fiber. The experimental studies demonstrate that lightweight concrete reinforced with basalt fiber has the highest deformability. In comparison with glass fiber, basalt fiber has a higher tensile strength and a higher elastic modulus. The fact that the concrete matrix and basalt fiber work together better is primarily due to the best mechanical characteristics of the basalt fiber. Further research prospects are determined in terms of determining the adhesion strength of various types of fibers with a matrix and studying the effect of this indicator on both the strength and deformation characteristics of lightweight concrete.
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Resende, Douglas Mol, José Maria Franco de Carvalho, Bárbara Oliveira Paiva, Gustavo dos Reis Gonçalves, Lais Cristina Barbosa Costa, and Ricardo André Fiorotti Peixoto. "Sustainable Structural Lightweight Concrete with Recycled Polyethylene Terephthalate Waste Aggregate." Buildings 14, no. 3 (February 26, 2024): 609. http://dx.doi.org/10.3390/buildings14030609.
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Plastic is a widely consumed material with a high decomposition time, occupying significant space in landfills and dumps. Thus, strategies to reuse plastic waste are imperative for environmental benefit. Plastic waste is a promising eco-friendly building material for cement-based composites due to its reduced specific gravity and thermal conductivity. However, this waste reduces the composites’ mechanical strength. This work aims to produce and evaluate lightweight concretes made with only lightweight aggregates and mostly recycled plastic aggregates. Initially, an optimized dosage approach for lightweight concrete is presented. The mixture proportion of the lightweight concrete was based on the performance of mortars with the complete replacement of natural aggregate by recycled polyethylene terephthalate (PET) aggregates. The PET aggregates showed irregular shapes, impairing workability and providing lightweight concretes with around 18% water absorption and 21% void index. However, the concretes presented significantly low-unit weight, approximately 1200 kg/m3. This work presented a structural lightweight concrete (ACI 213-R) using only lightweight aggregates and mostly plastic waste aggregate, with a compressive strength of up to 17.6 MPa, a unit weight of 1282 kg/m3, and an efficiency factor of 12.3 MPa·cm3/g. The study shows that with an optimum dosage, reusing plastic waste in concrete is a viable alternative contributing to environmental sustainability.
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Khoshvatan, Mehdi, and Majid Pouraminia. "The Effects of Additives to Lightweight Aggregate on the Mechanical Properties of Structural Lightweight Aggregate Concrete." Civil and Environmental Engineering Reports 31, no. 1 (March 1, 2021): 139–60. http://dx.doi.org/10.2478/ceer-2021-0010.
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Abstract In the paper, the effects of different percentages of additives (perlite, LECA, pumice) on the mechanical properties of structural lightweight aggregate concrete were tested and evaluated. For the research, 14 mixing designs with different amounts of aggregate, water, and cement were made. Experimental results showed that the specific gravity of lightweight structural concrete made from a mixture of LECA, pumice, and perlite aggregates could be 25-30% lighter than conventional concrete. Lightweight structural concrete with a standard specific gravity can be achieved by using a combination of light LECA with perlite lightweight aggregates (LA) and pumice with perlite in concrete. The results indicated that LECA lightweight aggregates show more effective behavior in the concrete sample. Also, the amount of cement had a direct effect on increasing the strength regardless of the composition of LAs. The amount of cement causes compressive strength to increase. Furthermore, the stability of different experimental models increased from 156 to 345 kg m 3 while increasing the amount of cement from 300 to 400 kg m 3 in the mixing designs of LECA and perlite for W/C ratios of 0.3, 0.35, and 0.4. For a fixed amount of cement equal to 300 kg, the compressive strength is reduced by 4% by changing the water to cement ratio from 0.5 to 0.4. The compression ratios of strength for 7 to 28 days obtained in this study for lightweight concrete were between 0.67-0.8. Based on the rate of tensile strength to compressive strength of ordinary concretes, which is approximately 10, this ratio is about 13.5 to-17.8 in selected and optimal lightweight concretes in this research, which can be considered good indirect tensile strength for structural lightweight concretes.
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Inozemtcev, Alexandr Sergeevich, and Evgeniy Valerjevich Korolev. "Technical and Economical Efficiency for Application of Nanomodified High-Strength Lightweight Concretes." Advanced Materials Research 1040 (September 2014): 176–82. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.176.
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The development of construction technologies is impossible without the proper estimation of economical efficiency. Some results of technical and economical efficiency of the developed high-strength structural lightweight concretes are presented in the article. Overview concerning world practice of research and application of lightweight concrete composition are made. The main properties and advantages of developed energy efficient high-strength lightweight concretes are described. The method of calculation of economic efficiency of concrete by means of reduction of total construction weight and increasing of floors’ number is proposed. Dependence between efficiency, footprint of building and number of floors is presented. It is shown that economical calculation for developed material which is based only on the cost of the material itself does not allow to obtain adequate data concerning prospect and competitiveness of the material. The authors offer method of calculating the economic efficiency of the developed high-strength lightweight concrete which takes into account the technical properties of the new material. The results of the study showed that the application of high-strength lightweight concrete is more effective than traditional kinds of the concretes.
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Jose, Christin, Ganga Radhakrishnan, Abhinav Anandan, Althaf T A, and Sankar B. "Review of Mechanical, Durability, and Thermal properties of Light weight concrete containing cenosphere." E3S Web of Conferences 529 (2024): 01032. http://dx.doi.org/10.1051/e3sconf/202452901032.
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Compared to conventional concrete, lightweight concrete offers a reduced unit weight, making it easier to handle and transport. Its popularity has surged globally in numerous countries and has proven beneficial for construction purposes. Lightweight concrete often exhibits better thermal insulation properties compared to traditional concrete, contributing to energy efficiency in buildings. Recently, the inclusion of cenospheres in lightweight aggregates is being is heavily researched around the world. Ceneosphere addition increases the volume of the concrete mixture because of their smaller size and hollow nature of the particle. This research paper showcases the various applications and advantages of lightweight concrete (LWC) containing cenosphere, along with highlighting the role of different supplementary cementitious materials characteristics and manufacturing methods. Furthermore, the current study examines previous researches on sustainable lightweight concretes and showcases the improvements and advancements in mechanical, durability, and thermal properties obtained when cenospheres were added.
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Bideci, Alper, Özlem Sallı Bideci, Sabit Oymael, and Hasan Yıldırım. "Analysis of shrinkage and creep behaviors in polymer-coated lightweight concretes." Science and Engineering of Composite Materials 23, no. 1 (January 1, 2016): 77–83. http://dx.doi.org/10.1515/secm-2014-0028.
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AbstractThe creep and shrinkage properties of polymer-coated lightweight concretes were examined. Five-hundred-dose lightweight concretes were produced by coating pumice aggregates with three different polymers (Sonomeric1: SNMC, KB Pur 214: KBP, and Polipol3455: PLP). The 3-, 7-, and 28-day compressive strength values of the obtained lightweight concrete samples were determined, and the 840-h and 12-month creep and shrinkage deformations were measured. It was found that the ductility of the SNMC- and KBP-coated concrete samples increased, while their shrinkage deformation results decreased when compared with the control samples. In contrast, the ductility of PLP concrete samples decreased and the shrinkage deformation became higher. In conclusion, the use of SNMC- and KBP-coated pumice aggregates had a positive effect on the creep and shrinkage properties of the concrete. Furthermore, it was observed that the compressive strength values of the lightweight concretes made of the coated samples were higher than those of the control sample.
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Ibrahim, Rahel Khalid. "The Effect of Elevated Temperature on the Lightweight Aggregate Concrete." Kurdistan Journal of Applied Research 2, no. 3 (August 27, 2017): 193–96. http://dx.doi.org/10.24017/science.2017.3.38.
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The use of lightweight concrete has become widely spread in concrete structures in the last years. Fire can be considered as a destructive hazard that attack concrete structures. In this research the effect of elevated temperature on lightweight aggregate concretes is studied. For this purpose, 81 cube shaped specimens were prepared from three different lightweight aggregate concrete mixes. After moist curing periods for 3, 7 and28 days, the specimens were subjected to ambient and elevated temperatures of 450⁰C and 650⁰C for 2hrs.The weight of the specimens before and after exposure to elevated temperatures was determined and the residual strength results for the specimens were compared. The results showed that, the elevated temperature induces a decrease in strength and significant weight losses in lightweight aggregate concrete.
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Ozyildirim, H. Celik, and Harikrishnan Nair. "Durable Concrete Overlays in Two Virginia Bridges." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 27 (June 11, 2018): 78–87. http://dx.doi.org/10.1177/0361198118777606.
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The purpose of this study was to implement innovative concretes with low permeability and reduced cracking potential in overlays to reduce chloride infiltration into the bridge decks. Two parallel bridges on Route 64 over Dunlap Creek in Alleghany County, Virginia, were selected for this study. For low cracking potential, relatively low water contents, shrinkage reducing admixtures, and lightweight aggregates were used. For low permeability, concretes had supplementary cementitious material and relatively low water–cementitious material ratios. In the overlays, five different materials were used: latex-modified concrete with rapid set cement; silica fume concrete alone; and silica fume concrete with shrinkage reducing admixture, lightweight coarse aggregate, and partial lightweight fine aggregate. A compressive strength of 3,000 psi at 3 days was sought. The performance of the overlay concretes was observed after two to three winters. The overlays used in this study achieved the specified strength and low permeability. There were minimal tight cracks except for one section with the latex-modified concrete with rapid set cement in the left lane of the westbound bridge. The extensive cracks in that section were attributed to plastic shrinkage from adverse weather conditions at placement and the fact that a truck had caught fire in that lane. Silica fume concrete overlays with shrinkage reducing admixture, lightweight coarse aggregate, or lightweight fine aggregate are ready for implementation in the field for low cracking overlays.
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Miryuk, Olga. "Service properties of porous liquid glass concrete." E3S Web of Conferences 410 (2023): 01008. http://dx.doi.org/10.1051/e3sconf/202341001008.
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The article presents studies’ results of cementless lightweight concretes based on porous granular aggregate. Lightweight concrete components are specially synthesized from mixtures containing liquid sodium glass and thermal energy waste with various fineness. Thermal hardening of a matrix based on liquid glass and technogenic fillers at a temperature of 350ºС provided heat-insulating concrete with 480 kg/m3density and compressive strength of 4.7 MPa. The aim of the work is to study operational stability of lightweight concrete from genetically related components. Durability of lightweight concrete was evaluated in terms of hydro physical properties, resistance to frost and salt aggression, and cyclic heating. Methods of physical and mechanical testing of concrete have been used in the work. X-ray phase analysis and electron microscopy were used to study materials’ composition and structure. The results of complex tests showed stability of the structure of liquid glass concrete based on porous aggregate to the impact of operational factors. The lightweight concretes developed are characterized by a softening coefficient of 0.81; they withstood 50 cycles of alternating freezing and thawing, 20 cycles of cyclic exposure at a temperature of 1050ºС and 20 thermal cycles at a temperature of 250ºС; staying in aggressive sulfate and chloride magnesium solutions.
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Dhengare, Sagar W., Ajay L. Dandge, and H. R. Nikhade. "Cellular Lightweight Concrete." Journal of Advance Research in Mechanical & Civil Engineering (ISSN: 2208-2379) 2, no. 4 (April 30, 2015): 22–25. http://dx.doi.org/10.53555/nnmce.v2i4.332.
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Cellular Light weight Concrete (CLWC) is not a new invention in concrete world. It has been known since ancient times. It was made using natural aggregates of volcanic origin such as pumice, scoria, etc. The Greeks and the Romans used pumice in building construction. Lightweight concrete can be defined as a type of concrete which includes an expanding agent in that it increases the volume of the mixture while giving additional qualities such as inability and lessened the dead weight. The usage of Cellular Light-weight Concrete (CLC) blocks gives a prospective solution to building construction industry along with environmental preservation.
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Pereira, Wesley Batista, Simone Perruci Galvão, Juliana Claudino Veras, and João Manoel de Freitas Mota. "Mix desing method lightweight concrete." Revista de Gestão e Secretariado 15, no. 2 (February 19, 2024): e3509. http://dx.doi.org/10.7769/gesec.v15i2.3509.
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There are several methodologies for Portland cement concrete dosage, among these, the method recommended by the Technological Research Institute of the State of São Paulo - IPTUSP, which is widespread in Brazil. Although it does not present dosage factors for lightweight concrete, this paper proposes a dosage method based on the IPT method for lightweight concrete with EPS. The concrete was dosed with CPV ARI cement, sand and EPS, and two volumes of aggregates (m) were made, thus making a rich and a poor trace, for this, two aggregate contents (m) were executed, thus making a rich and a poor mix, being them: 1:1, 1:2 (aggregates mix in real volume (L) per kg of cement), respectively. Then, each mix (1:m) was dosed with three different levels of EPS (25, 50 and 75%, to each "m"). The properties of the concretes were evaluated in the fresh state, through the slump test [1] and specific mass through the known volume method, and, in the hardened state, by the specific mass test [2] and compressive strength [3]. With the results obtained from this study, it was possible to elaborate a dosage diagram for each "m" analyzed, obtaining the values of the EPS content, projection of compressive and slump resistance, indicated in a dosage abacus made from the test results, these parameters are essential for the determination of the concrete mix.
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Litsomboon, Theradej, Pichai Nimityongskul, and Naveed Anwar. "Development of Lightweight Aggregate Concrete Containing Pulverized Fly Ash and Bottom Ash." Key Engineering Materials 400-402 (October 2008): 379–84. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.379.
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This study examines the feasibility of using different lightweight aggregates (LA) and bottom ash as coarse and fine aggregates in concrete with fly ash. The lightweight materials were composed of 3 types, namely pumice, cellular lightweight aggregate and MTEC lightweight aggregate. The tests for physical and mechanical properties of lightweight aggregate concretes (LWAC) were conducted in terms of workability, compressive strength, apparent density, abrasion resistance and absorption. Test results showed that compressive strength of LWAC increased with an increase in apparent density, which is mainly depending on the type of aggregate. The replacement of normal weight sand with bottom ash resulted in a decrease both in density of concrete by 180-225 kg/m3 and 28-day compressive strength of concrete by 16-26%. Moreover, the use of bottom ash to replace sand in concrete increased the demand for mixing water due to its porosity and shape and to further obtain the required workability. The type and absorption of LA influenced predominantly the water absorption of LWAC. Total replacement of natural sand by bottom ash increased the absorption of the concrete by 63-90%. With regard to abrasion resistance, the abrasion resistance of lightweight aggregate concrete was mainly dependent on the compressive strength of concrete: the higher the strength, the higher the abrasion resistance of LWAC. In addition, the use of bottom ash as a fine aggregate resulted in a lower abrasion resistance of lightweight aggregate concrete due to its porosity. Of the three types of lightweight materials, MTEC LA had achieved both low density and high compressive strength.
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Lee, Ming Ju, Ming Gin Lee, Jing Yu Chen, and Mang Tia. "Strength and Freeze-Thaw Testing of Lightweight Aggregate Concretes." Advanced Materials Research 723 (August 2013): 507–14. http://dx.doi.org/10.4028/www.scientific.net/amr.723.507.
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This investigation indicates the effects of freeze-thaw cycles on the strength development and durability of lightweight aggregate concretes. Two lightweight aggregate concrete, one normal concrete and one reactive powder concrete were used in this study, and total four types of concrete mix were named NC, LWC1, LWC2, and RPC. Before and after freeze-thaw test, the samples were evaluated by the compressive strength, fflexural strength, and impact abrasion tests. The test results show that steady decrease in compressive and flexural strength after freeze-thaw testing for most concrete specimens. The lightweight aggregate used in the LWC1 mix for this laboratory study had a good freeze-thaw performance history, but the LWC2 mix with lightweight aggregate approaching the 24-hour water absorption had a bad result. It might be due to the void volume required to release hydraulic pressure developed during cyclic freezing.
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Kitouni, S., and H. Houari. "Lightweight concrete with Algerian limestone dust: Part I: Study on 30% replacement to normal aggregate at early age." Cerâmica 59, no. 352 (December 2013): 600–608. http://dx.doi.org/10.1590/s0366-69132013000400017.
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The mechanical characteristics of the lightweight aggregate concretes (LWAC) strongly depend on the proportions of aggregates in the formulation. In particular, because of their strong porosity, the lightweight aggregates are much more deformable than the cementations matrix and their influence on concrete strength is complex. This paper focuses on studying the physical performance of concrete formulated with substitution of 30% of coarse aggregates by limestone dust. In this article an attempt is made to provide information on the elastic properties of lightweight concrete (LWC) from tests carried out under uniaxial compression conditions. The results of Young modulus, Poisson's ratio, and compressive and flexural tensile strength tests on concrete are presented. The concretes obtained present good mechanical performances reaching 34.99 MPa compressive strength, 6.39 MPa flexural tensile strength and in front of 36 MPa Young modulus.
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Alqahtani, Fahad K. "A Sustainable Alternative for Green Structural Lightweight Concrete: Performance Evaluation." Materials 15, no. 23 (December 2, 2022): 8621. http://dx.doi.org/10.3390/ma15238621.
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The use of structural lightweight concrete in the construction industry is on the rise in the last few decades mainly because of the higher strength per unit density, as it reduces the total deal load of the structural elements as compared with normal strength concrete. In addition, the environmental concerns of the concrete industry have gained supreme importance in recent times, demanding vital and effectual steps. In this regard, the current study was carried out to formulate an alternative approach for producing a sustainable lightweight structural concrete. The study followed two stages: initially, the selection of optimized manmade plastic aggregates based on trial concrete mixes, and finally, to gauge the physical-, mechanical- and durability related properties of the concretes integrating optimized manmade aggregate series at different replacement fractions. As a result of the first phase: two aggregate series out of eight were selected based on the compressive strength and durability properties of their concretes. In the next stage, all the properties for the optimized aggregate concrete were analyzed in terms of compressive strength. It was noted that the physical, mechanical and chloride penetration resistances have generally displayed a decreasing trend, with an increase in the manmade plastic aggregate replacement fractions as compared with reference lightweight concrete. However, the two aggregates, i.e., 70% DS-30% LLDPE and 50% QF-50% PET at the replacement fractions of 25% and 100%, were found to be the best two contenders that fulfilled the criteria for structural lightweight concrete, i.e., ASTMC330/C330M-14, and were proposed for structural lightweight purposes with low and relatively high strength and chloride resistance-based durability requirements, respectively. In addition, the brittleness ratios and structural efficiency parameters for the concretes of the 70% DS-30% LLDPE and 50% QF-50% PET also supplemented the aforementioned findings. Overall, this study presents a sustainable approach for the effective utilization of plastic waste for producing structural lightweight concrete.
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Anish, M., T. Arunkumar, J. Jayaprabakar, Sami Al Obaid, Saleh Alfarraj, M. M. Raj, and Assefa Belay. "Thermal Conductivity of Thermally Insulated Concretes in a Nuclear Safety Vessel of Reactor Vault: Experimental Interpretation." Advances in Materials Science and Engineering 2022 (June 21, 2022): 1–12. http://dx.doi.org/10.1155/2022/4493910.
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Thermally insulated concretes are a type of alternative building material that helps improve thermal efficiency in nuclear reactor vault safety vessel applications. The experimental results of thermal conductivity values of lightweight concrete materials at various temperatures are presented in this paper. To minimize heat conduction in concrete, different lightweight aggregates and vermiculite are employed as coarse aggregate alternatives.Both linear and plane heat source approaches are used to calculate the thermal conductivity values of the specimens. The findings emphasize that increasing the proportion of lightweight particles in concrete may dramatically lower the thermal conductivity, with the kind of lightweight aggregates having a vital role in thermal insulation. The inclusion of micron-sized vermiculite decreases heat conductivity even further; however, the effect is less obvious than that of lightweight particles.
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Mieszczak, Małgorzata, and Lucyna Domagała. "Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab." Materials Science Forum 926 (July 2018): 140–45. http://dx.doi.org/10.4028/www.scientific.net/msf.926.140.
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The paper presents the results of tests conducted on two lightweight aggregate concretes made of new national Certyd artificial aggregate. This research is intended to first application of lightweight concrete to construct large-span post-tensioned slab. In addition to mechanical properties development, shrinkage and creep during 3 months of loading were tested. The obtained results are compared with theoretical results predicted by standard. Conducted tests indicated, that measured values of shrinkage and creep are significantly lower than predicted ones. This is promise for application of tested concrete in construction of post-tensioned slabs.
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Przychodzień, Patrycja, and Jacek Katzer. "Properties of Structural Lightweight Aggregate Concrete Based on Sintered Fly Ash and Modified with Exfoliated Vermiculite." Materials 14, no. 20 (October 9, 2021): 5922. http://dx.doi.org/10.3390/ma14205922.
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Despite the undoubted advantages of using lightweight concrete, its actual use for structural elements is still relatively small in comparison to ordinary concrete. One of the reasons is the wide range of densities and properties of lightweight aggregates available on the market. As a part of the research, properties of concrete based on sintered fly ash were determined. The ash, due to its relatively high density is suitable to be used as a filler for structural concretes. Concrete was based on a mixture of sintered fly ash and exfoliated vermiculite aggregate also tested. The purpose of the research was to determine the possibility of using sintered fly ash as alternative aggregate in structural concrete and the impact of sintered fly ash lightweight aggregate on its physical, mechanical and durability properties. Conducted tests were executed according to European and Polish standards. Created concretes were characterized by compressive strength and tensile strength ranging from 20.3 MPa to 54.2 MPa and from 2.4 MPa to 3.8 MPa, respectively. The lightest of created concretes reached the apparent density of 1378 kg/m3.
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Varikuppala, Lalitha, and G. V. V. Satyanarayana. "Mix proportioning of M25 grade concrete by replacing normal aggregate with light weight aggregate (Pumice)." E3S Web of Conferences 391 (2023): 01197. http://dx.doi.org/10.1051/e3sconf/202339101197.
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Day to day a large development in construction activities are happening. All constructions require huge quantity of concrete. All we know that conventional concrete has density 2400 kg/m3.This type of concrete is not at all required in all aspects. So that new era concretes are developed to solve more problems. In general Components of buildings have concrete density 2400 kg/m3. In high rise buildings the components are large in size. Thus, by making the components lighter, a concrete needs to have a lesser density while still retaining its adequate compressive capacity. Lightweight aggregate are employed when making the bulk of lightweight concrete. The objective of the current study is to develop lightweight concrete by replacement of pumice stone for natural aggregate for M25 grade, with pumice stone ranging proportion from 0-27.5% at 5% intervals.
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Basset, R., and S. M. Uzumeri. "Effect of confinement on the behaviour of high-strength lightweight concrete columns." Canadian Journal of Civil Engineering 13, no. 6 (December 1, 1986): 741–51. http://dx.doi.org/10.1139/l86-109.
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This paper summarizes an experimental investigation into the behaviour of high strength sand – lightweight concrete columns confined with rectangular ties. Fifteen reinforced and three unreinforced specimens were tested under monotonically increasing axial compression. Variables considered in this study were the longitudinal steel distribution and tie configuration, the tie steel spacing, the amount of tie steel, and the amount of longitudinal steel.The results indicated that unconfined high-strength lightweight aggregate concrete is a brittle material. The addition of lateral confining steel significantly improved the behaviour of this material, with a large amount of lateral steel resulting in very ductile behaviour. The tie configuration and resulting distribution of longitudinal steel contributed significantly to the confinement of concrete, with well-distributed steel resulting in improved behaviour. The ratio of specimen to cylinder concrete strength was observed to be 0.98, which is much higher than the commonly assumed value of 0.85.The test results were compared with results from selected theoretical confinement models. Based on the results of this investigation, existing models for concrete confinement give unconservative results for high-strength lightweight aggregate concrete and overestimate the ductility that can be achieved with this material. Key words: columns, confinement, ductility, high-strength concretes, lightweight aggregate concretes, reinforcement, stress–strain relationships, tests, ties, toughness.
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Gomes, Maria da Glória, José Alexandre Bogas, Sofia Real, António Moret Rodrigues, and Rita Machete. "Thermal Performance Assessment of Lightweight Aggregate Concrete by Different Test Methods." Sustainability 15, no. 14 (July 17, 2023): 11105. http://dx.doi.org/10.3390/su151411105.
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Structural lightweight aggregate concrete is currently an alternative to normal-weight concrete when thermal insulation properties are required to meet the objectives of energy efficiency and sustainability. The accurate evaluation of the thermal performance is thus essential for designing structural lightweight concrete elements. This paper aims to evaluate the thermal behavior of structural lightweight aggregate concrete, assessed through different tests methods. To this end, a vast experimental campaign was carried out involving specimens produced with several types of lightweight aggregate and different water/cement ratios. The thermal performance was established by thermal conductivity, which was determined according to a modified transient pulse method and a quasi-stationary method, and specific heat capacity, which was determined through a transient pulse method and a heat transfer method. Normal-weight concrete was also tested for comparison purposes. Experimental evidence showed that lightweight aggregate concretes with lower density are associated with up to about 50% lower thermal conductivity and higher specific heat capacity than normal-weight concrete. Moreover, the study demonstrated that the expeditious transient pulse method is suitable for assessing the thermal conductivity of this type of concrete, and that both the transient pulse method and the heat transfer method are adequate to determine the specific heat capacity.
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Wathoni, Muhammad Munawir, Dwi Sabda Budi Prasetya, and Dwi Pangga. "Uji Mekanik Bata Ringan Berbahan Dasar Limbah Pengolahan Emas dengan Variasi Limbah Batu-bara dan Semen." Jurnal Penelitian dan Pengkajian Ilmu Pendidikan: e-Saintika 2, no. 1 (December 31, 2018): 41. http://dx.doi.org/10.36312/e-saintika.v2i1.110.
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[Title: The Mechanical Test of Lightweight Brick Made from Gold Processing Waste with Variations in Coal and Cement Waste]. The purposes of this research are to make lightweight concrete using waste processing of gold with variation fly ash and cement the better than conventional concrete. The value of this research has tested mechanics which comprises density, porosity and strength. The research has done with some stage are: 1) Make lightweight concrete using LPE with variation fly ash and cement. 2) Characterization of the samples which comprise density, porosity and the strength, 3) Analysis of tested mechanical lightweight concrete. The value of lightweight concrete to make with variation composition fly ash and cement in a series are: (0/100), (5/95), (10/90), (15/85), (20/80) who are in volume. To make lightweight concrete with composition foam and water controlled as much as 10 ml and 150 ml at all of the sample. So we get the density value of lightweight concrete without fly ash is 1.61. In lightweight concrete with fly ash, we get the minimum density of lightweight is 1.15. The porosity value of lightweight concrete without fly ash is 13.6%, and the porosity value of lightweight concrete with fly ash is 8.0%. The compressive strength of lightweight concrete without fly ash is 1.629 MPa and the compressive strength of lightweight concrete with fly ash is 1.772 MPa. The value shown to process waste processing of gold with variation fly ash and cement to be lightweight concrete can get mechanical in character of lightweight to be better than conventional concrete.
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Mohamed Daood, Daad, and Dr Nadia Salim Esmaeil. "Processing Lightweight Aggregate to produce Lightweight Concrete." AL-Rafdain Engineering Journal (AREJ) 18, no. 6 (December 28, 2010): 10–23. http://dx.doi.org/10.33899/rengj.2010.35172.
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Ming, Liew Yun, Andrei Victor Sandu, Heah Cheng Yong, Yuyun Tajunnisa, Siti Fatimah Azzahran, Ridho Bayuji, Mohd Mustafa Al Bakri Abdullah, et al. "Compressive Strength and Thermal Conductivity of Fly Ash Geopolymer Concrete Incorporated with Lightweight Aggregate, Expanded Clay Aggregate and Foaming Agent." Revista de Chimie 70, no. 11 (December 15, 2019): 4021–28. http://dx.doi.org/10.37358/rc.19.11.7695.
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This paper investigates the effect of incorporation of lightweight aggregate and foam in the preparation of lightweight aggregate geopolymer concrete (LWAGC) and lightweight aggregate foamed geopolymer concrete (LWAFGC). The geopolymer paste was formed by alkali activation of Class F fly ash in mixture of sodium silicate and sodium hydroxide solution. LWAGC was incorporated with expanded clay lightweight aggregate and river sand while hydrogen peroxide was added as foaming agent for LWAFGC. Results showed that LWAGC and LWAFGC achieved an excellent 28-day compressive strength of 60 MPa and 20 MPa, respectively. The bulk densities were 1815 kg/m3 for LWAGC and 1593 kg/m3 for LWAFGC. Even so, low thermal conductivity of 0.12 W/mK and 0.09 W/mK were reported. It was concluded that the joint effect of lightweight aggregate and foam produced geopolymer concrete with good mechanical strength while having excellent thermal insulating properties. The geopolymer concretes possessed high strength-to-density ratio to be regarded as lightweight high-performance structures.
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Bodnárová, Lenka, Jitka Peterková, Jiri Zach, and Kateřina Sovová. "Determination of Thermal Conductivity on Lightweight Concretes." Key Engineering Materials 677 (January 2016): 163–68. http://dx.doi.org/10.4028/www.scientific.net/kem.677.163.
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A range of testing methods were used to study the potential structural changes as a result of the effects of high temperatures on lightweight types of concrete developed above all for fire resistant structures. One such test for monitoring changes in concrete structures is the non-stationary determination of the coefficient of thermal conductivity using the hot wire method. The matrix structure progressively collapses as a result of the effects of high temperatures on the concrete structure ́s surface because erosion takes place of the matrix and aggregate porous structures. The degradation of the porosity of the concrete results in the deterioration of its thermal insulating properties. This paper assesses the dependence of the thermal conductivity coefficient of lightweight concretes on temperature and determines the potential occurrence of structural changes in the lightweight concrete matrix. The results were verified using other methods to determine the concrete ́s resistance to thermal load.
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Medvedeva, G., and A. Lifant'eva A.F. "THE RESEARCH OF MULTILAYER OUTER FENCING INCLUDING MATERIALS USING ASH AND SLAG WASTE OF THERMAL POWER PLANTS." Construction Materials and Products 3, no. 2 (July 10, 2020): 29–35. http://dx.doi.org/10.34031/2618-7183-2020-3-2-29-35.
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the most important direction of resource saving in construction is the widespread use of secondary material resources, which are waste products. The use of secondary products of industry as raw materials for the production of various building materials is very important, because it provides production with rich sources of cheap and, often, already prepared raw materials; lead to lower costs for the production of some building materials, and therefore saves capital investments intended for the construction of buildings and structures; release large areas of land and reduce the impact on the environment. The article deals with heat-insulating and structural-heat-insulating materials, with partial replacement of components by ash-slag waste (ASW): lightweight concretes with broken glass and concretes modified with sulfur. Properties of concretes modified with sulfur are investigated: compressive strength, density and thermal conductivity. In accordance with the obtained properties, a comparative characteristics of the received materials with existing building materials was carried out: sulfur modified concrete and lightweight concrete; lightweight concrete using broken glass and claydite-concrete. Thermophysical calculation of multilayer hencing is made. In each of the options, one of the following materials was selected as a structural and heat-insulating material: lightweight concrete using broken glass and sulfur modified concrete. Also, for each type of hencing, the necessary heat-insulating and structural materials were selected. In the economic part, the cost of the raw materials necessary to obtain 1 m3 of the investigated materials and the cost of 1 m3 of multilayer hencing, which includes the investigated concrete, are calculated.
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Korolev, Evgeniy Valerjevich, and Alexandr Sergeevich Inozemtcev. "Preparation and Research of the High-Strength Lightweight Concrete Based on Hollow Microspheres." Advanced Materials Research 746 (August 2013): 285–88. http://dx.doi.org/10.4028/www.scientific.net/amr.746.285.
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The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensional modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300...1500 kg/m3 and compressive strength is 40...70 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m3are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production (in particular, for construction of high-rise buildings) have been justified. The results of industrial testing of new compositions in precast concrete technology are shown.
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Zha, Jin, Bei Xing Li, Jin Hui Li, He Gao, and Gong Cui. "Internal Curing of Saturated Lightweight Aggregate in High Performance Combined Concrete." Key Engineering Materials 405-406 (January 2009): 212–18. http://dx.doi.org/10.4028/www.scientific.net/kem.405-406.212.
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This paper investigated the mechanical properties, workability, autogenous shrinkage, drying shrinkage and durability of the high performance combined aggregate concrete with the coarse aggregate replaced by the lightweight aggregate in the volume fraction from 0% to 50%. The results demonstrated that the fresh concrete with the lightweight aggregate volume fraction of 10% and 30% had good workability, but degrade with a high volume fraction of 50 %. The hardened concrete with 10% and 30% lightweight aggregate replacement had similar compressive strength and splitting tensile strength comparing to the reference concrete without adding lightweight aggregate. The concrete with 50% lightweight aggregate replacement showed decreased compressive strength and splitting tensile strength. The concrete adding lightweight aggregate exhibited less autogenous shrinkage and drying shrinkage than the reference concrete without adding lightweight aggregate. The autogenous shrinkage and drying shrinkage increased with the increasing lightweight aggregate volume fraction. The concrete containing lightweight aggregate showed good durability after 200 freezing and thawing cycles, but the chloride permeability efficiency of concrete decreased.
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Alqahtani, Fahad K. "Sustainable Green Lightweight Concrete Containing Plastic-Based Green Lightweight Aggregate." Materials 14, no. 12 (June 15, 2021): 3304. http://dx.doi.org/10.3390/ma14123304.
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Nowadays the environment and its natural resources face many issues, related to the depletion of natural resources beside the increase in environmental pollution resulted from uncontrolled plastic waste disposal. Therefore, it is important to find effective and feasible solutions to utilize these wastes, such as using them to produce environmentally friendly green concrete. In this study, plastic-based green lightweight aggregates (PGLAs) containing PET plastic waste and by product additives were developed, and their subsequent physical and mechanical properties were compared with those of reference aggregates. Then, green lightweight aggregate concrete mixes (GLACs) were produced at 100% replacement of normal weight and lightweight coarse aggregate with developed PGLAs; and their fresh, hardened, microscopic and durability-related properties were compared to those of control mixes. Study results revealed that the unit weight of PGLAs were 21% to 29% less than that of normal coarse aggregate. Additionally, PGLAs had low water absorption that varied between 1.2% and 1.6%. The developed aggregates had 45% higher strength compared to that of lightweight coarse aggregate. Study results confirmed that structural green lightweight aggregate concretes (GLACs), that satisfied the dry density, compressive and splitting tensile strength requirements specified in ASTM C330, were feasibly produced. Finally, GLACs had low-to-moderate chloride penetration in accordance with ASTM C1202, thus it can be used in those areas exposed to the risk of chloride attack.
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Yao, Weijing, Jianyong Pang, and Yushan Liu. "Performance Degradation and Microscopic Analysis of Lightweight Aggregate Concrete after Exposure to High Temperature." Materials 13, no. 7 (March 28, 2020): 1566. http://dx.doi.org/10.3390/ma13071566.
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This study analyses the deterioration of mechanical properties in lightweight concrete after exposure to room temperature (20 °C) and high temperature, i.e., up to 1000 °C, including changes in visual appearance, loss of mass, and compressive strength. All-lightweight shale ceramsite aggregate concrete (ALWAC) and semi-lightweight shale ceramsite aggregate concrete (SLWAC) are prepared using an absolute volume method to analyse the relationships between relative ultrasonic pulse velocity, loss rate of compressive strength, damage degree, and temperature levels. Our results show that, under high temperature, the lightweight aggregate ceramsite concrete performs better compared to normal concrete. After exposure to 1000 °C, the ALWAC shows a strength loss of no more than 80%, while the normal concrete loses its bearing capacity, with a similar strength loss as the SLWAC. Furthermore, the relative ultrasonic pulse velocity and damage degree are used to evaluate the effects of high temperature on the concretes, including the voids and cracks on the surface and inside of the specimens, which induces the deterioration of mechanical properties and contributes to the thermal decomposition of the cementing system and the loss of cohesion at the aggregate interface. Based on internal structure analyses, the results from this study confirm that the lightweight aggregate concrete shows a high residual compressive strength after exposure to the high temperature.
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Ahmed, Ahmed Rabie, Magdy El Yamany, and Ahmed El Kholy. "High Strength Lightweight Concrete, using Scoria and Mineral Admixture." International Journal of Membrane Science and Technology 10, no. 2 (August 19, 2023): 3463–71. http://dx.doi.org/10.15379/ijmst.v10i2.3151.
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The purpose of this study is to investigate a high-strength lightweight concrete (HSLWC) using Scoria aggregate and mineral admixtures. The experiment findings are presented in this paper. In the concrete mix, basaltic (scoria) was used as a lightweight aggregate. A control lightweight concrete mixture made with lightweight basaltic (scoria) containing ordinary Portland cement as the binder was prepared. The control lightweight concrete mixture was modified by replacing 10% of the cement with silica fume. The control lightweight concrete mixture was also modified by replacing 10% of the cement with metakaolin. A third mixture of lightweight concrete was also prepared, modifying the control lightweight concrete by replacing 10% of the cement with metakaolin and 10% of the cement with silica fume.
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Aslam, Muhammad, Payam Shafigh, and Mohd Zamin Jumaat. "Structural Lightweight Aggregate Concrete by Incorporating Solid Wastes as Coarse Lightweight Aggregate." Applied Mechanics and Materials 749 (April 2015): 337–42. http://dx.doi.org/10.4028/www.scientific.net/amm.749.337.
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Structural lightweight aggregate concrete offers several benefits as compared to the normal weight concrete. Most common methods of producing structural lightweight concrete is by using artificial lightweight aggregates. However, the cost of the production of artificial lightweight aggregates is high due to energy and raw materials consumption. The use of waste and by-product materials as lightweight aggregate in concrete can provide a better solution to reducing the negative impact of the concrete industry. This paper reports an investigation to produce structural lightweight aggregate concrete by utilizing the locally available solid waste materials, namely oil palm shell (OPS) and oil-palm-boiler clinkers (OPBC) as coarse lightweight aggregates. Two different mix proportions were studied. In the first concrete mix, just OPS was used as coarse aggregate. However, 40% of OPS (by volume) of the first mix was replaced with OPBC in the second mix. The test results showed that by replacing OPS with OPBC, it directly affects the characteristics of the lightweight concrete. The 28-days compressive strength of the blended coarse lightweight aggregate concrete was significantly increased compared to OPS concrete.
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Bibora, P., V. Prachar, O. Svitak, and R. Zavrelova. "Light autoclaved foam concrete with foam glass-based aggregate." IOP Conference Series: Materials Science and Engineering 1205, no. 1 (November 1, 2021): 012006. http://dx.doi.org/10.1088/1757-899x/1205/1/012006.
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Abstract The presented research aims to develop new optimized composition of novel lightweight concrete with a very low bulk density. Low bulk density of developed lightweight concrete is achieved by using a combination of non-traditional lightweight artificial fillers, dispersed fibre reinforcement and pre-generated technical foam. The methodology of lightweight concrete test specimen production, based on technologies commonly applied for the production of lightweight concrete, foam concrete or autoclaved aerated concrete was also designed and verified. Not only the physical and mechanical parameters, but also the thermal insulation properties were verified on the produced test specimens of the developed lightweight concrete.
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Hoang Minh, Duc, and Ly Le Phuong. "Effect of matrix particle size on EPS lightweight concrete properties." MATEC Web of Conferences 251 (2018): 01027. http://dx.doi.org/10.1051/matecconf/201825101027.
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Expanded polystyrene lightweight concrete is a composite which can be made by adding expanded polystyrene aggregate in normalweight concrete (as matrix). The research was focused on the effect of properties and volume of the matrix on the properties of lightweight concrete. The results show that properties of structural polystyrene concrete, such as workability and compressive strength, depend on the aggregate size of the matrix. It also shows that decreasing aggregate size of the matrix is the effective way to increase workability and compressive strength of lightweight concrete. When the density of concretes decrease by 200 kg/m³, slump values decrease by about 20 to 30 mm with lightweight concrete mixtures using maximum particle size of 0.63 mm, while slump values decrease by about 40 mm with the mixtures using maximum particle size of 20 mm. At the same density, the compressive strength of the structural polystyrenre concrete significantly decreased when the coarse aggregate diameter greater than 10 mm. Therefore, coarse aggregates with diameter size are smaller than 10 mm was recommended to use for matrix. In the result, expanded polystyrene concrete with density from 1,400 kg/m³ to 2,000 kg/m³ and compressive strength more than 20 MPa for structural application was made.
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Mohammed Jawad, Raed K., Mohammed J. Kadhim, and Hamza M. Kamal. "A REVIEW OF THE EFFECT OF ADDITIVES ON THE MECHANICAL PROPERTIES OF LIGHTWEIGHT CONCRETE." Journal of Engineering and Sustainable Development 27, no. 6 (November 1, 2023): 713–24. http://dx.doi.org/10.31272/jeasd.27.6.4.
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Many organizations around the world have recognized lightweight, long-lasting, cost and environmentally-friendly construction materials as a future necessity. The lightweight concrete is manufactured mainly either by replacing the original aggregate with lightweight aggregate or addition foam production materials to concrete mixtures. These additions lead to a decrease in the lightweight concrete density and change mechanical properties such as compressive strength. Therefore, there is much experimental research has been conducted to add different material types that can improve lightweight concrete compressive strength while maintaining low density. In this review, the effect of various additions such as steel fiber, product waste materials, and nano-materials on the lightweight concrete compressive strength and density have been explained. The various effects of these additive materials on lightweight concrete properties, some additives lead to improving the properties of lightweight concrete, while other materials lead to a decrease in those properties, and this depends on the type and amount of material additive, the method lightweight concrete manufacturing, and their mixture composition.
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Cibulka, Tereza, Luboš Musil, and Jan Vodička. "THE LIGHTWEIGHT TEXTILE REINFORCED CONCRETE FOR THIN-WALLED STRUCTURES." Acta Polytechnica CTU Proceedings 22 (July 25, 2019): 17–21. http://dx.doi.org/10.14311/app.2019.22.0017.
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The article deals with lightweight concrete with non-conventional reinforcement and its application in thin-walled structures. As part of experimental research, several sets of thin-walled slab and complementary specimen were made to determine the material characteristics of lightweight concrete. The porous aggregate Liapor was used in the recipe. Two-dimensional carbon and 3D glass textiles were used as reinforcement. The impact study of different casting technologies and recipe on the material characteristics of lightweight concrete was included in the research. Fresh concrete for the slab production was placed in special wooden molds. The slabs were concreted in vertical and horizontal position. The casting method has a significant impact on the element material characteristics. Reinforced specimens have shown high strength, even in thin-walled structures with low bulk density.
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Okamoto, T., Y. Ishikawa, T. Tochigi, and M. Sasajima. "High Performance Lightweight Concrete." Concrete Journal 37, no. 4 (1999): 12–18. http://dx.doi.org/10.3151/coj1975.37.4_12.
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Hubertova, Michala, and Rudolf Hela. "Lightweight High Performance Concrete." IABSE Symposium Report 92, no. 18 (January 1, 2006): 1–8. http://dx.doi.org/10.2749/222137806796169704.
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Abdul-Moghni, Hassan S. "LIGHTWEIGHT CONCRETE IN YEMEN." JES. Journal of Engineering Sciences 38, no. 2 (March 1, 2010): 437–47. http://dx.doi.org/10.21608/jesaun.2010.124375.
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Hubertova, Michala, and Rudolf Hela. "Lightweight Fibre Reinforced Concrete." Solid State Phenomena 249 (April 2016): 28–32. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.28.
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The use of fibre reinforcement in normalweight concrete technology is commonly used in practice. In the area of lightweight concrete, for example with use of expanded clay aggregate, there is not widely used this type of technology. The paper describes the experimental verification of various doses of steel fibres in two types of bulk and compressive class of lightweight expanded clay aggregate concrete and its influence on the physical and mechanical properties of hardened concrete – compressive and flexural strength, stress-strain diagram.