Performance of self-compacting concrete incorporating recycled concrete fines and aggregate exposed to sulphate attack

Boudali, S.; Kerdal, D.; Ayed, Kada; Abdulsalam, Bahira; Soliman, Ahmed M.

doi:10.1016/j.conbuildmat.2016.06.058

Cited by 88 publications

(49 citation statements)

References 28 publications

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“…These results coincide with the reported by [16], who attribute an improvement in the concretes compressive strength due to use the greater an amount of RA in replacement of conventional aggregates combined with coal ash or artificial pozzolans, due that RA improve the pozzolanic reaction of the ash, leads to a greater pore structure and interfacial transition zone (ITZ) refinement in the matrices of the material. According to [17], in concretes with replacements up to 40% of RA, the development of mechanical resistance improved due to CH and C-S-H present in the recycled aggregates acted as nucleation sites, accelerating hydration reactions and stimulating the formation of new hydration products. The CH also acts as a sink for calcium and silicate ions, which allows further dissolution of tricalcium silicate (C 3 S) (F.M.…”

Section: Concrete Compression Strengthmentioning

confidence: 99%

Sustainable Concrete Application in the Manufacture of University Urban Furniture

et al. 2019

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It is clear that construction and demolition wastes (CDW) are constantly increasing throughout the world and these wastes can be used effectively to minimize the consumption of natural resources in the manufacture of more sustainable concrete. The CDW occupy an important segment of world waste production and its generation reached approximately 3 billion tons in 2012 in 40 countries [1]. Although this topic has been studied in the world, it is still valid for the reuse of waste that is constantly increasing, and although in many countries there are already examples of its use this type of concrete in Colombia and in the Medellì n city lacks applications. This project proposes the application of a sustainable concrete made with CDW and coal ash in the Medellí n city for its implementation in the construction of urban furniture. A university community diagnosis of the needs in terms of furnishing was made. With the design reached, a modular chair was proposed to enable spaces within the university. The mechanical characteristics of the concrete and the design of the chair are evaluated and a simulation is done through finite elements to evaluate the viability of the proposed concrete, finding that with these properties is possible to manufacture durable and sustainable furniture that serves as an example for the application of sustainable materials , 0 0 (201 MATEC Web of Conferences https://doi.org/10.1051/matecconf/2019 0 9) ICBMM 2019 303 3030 50 1 50 1 , 0 0 (201 MATEC Web of Conferences https://doi.org/10.

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Section: Concrete Compression Strengthmentioning

confidence: 99%

Sustainable Concrete Application in the Manufacture of University Urban Furniture

et al. 2019

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“…As propriedades reológicas da argamassa de referência são sintetizadas na Tabela 7, onde é possível observar o incremento da tensão de escoamento e da viscosidade ao longo do tempo, comportamento este, relacionado ao processo de hidratação e formação da miscroestrutura do cimento. 5 12,876 0,8913 0,0038 0,9991 30 24,848 0,9470 0,0043 0,9968 60 35,923 1,2132 0,0034 0,9923 Observa-se por meio da análise dos dados da Tabela 8, que a argamassa ARG-AMR, com 0,40% de aditivo, apresentou tensão de escoamento e viscosidade superiores às da argamassa ARG-REF. Esse aumento na tensão de escoamento atingiu uma magnitude tal que, após 60 minutos, não foi possível ensaiar a mistura no reômetro por limitação de torque do equipamento.…”

Section: Argamassaunclassified

“…Entretanto, GRDIC et al [9] não verificaram decréscimo significativo na resistência à compressão de concretos autoadensáveis produzidos com substituição de 50 e 100% da fração graúda natural por brita reciclada. BOUDALI et al [60] relataram ligeiro incremento na resistência à compressão de um CAA que empregou 100% de agregado graúdo reciclado.…”

Section: Resistência à Compressãounclassified

Influência dos agregados reciclados nas propriedades reológicas e mecânicas do concreto autoadensável

et al. 2018

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RESUMOA reciclagem da fração mineral dos resíduos de construção e demolição (RCD), na forma de agregados, é vista como uma alternativa para a redução dos impactos ambientais provocados pela construção civil. Os agregados reciclados apresentam maior absorção de água e menor resistência mecânica e densidade quando comparados aos agregados naturais, fatores esses que irão influenciar as propriedades dos concretos produzidos. Assim, o objetivo deste estudo foi investigar a influência dos agregados reciclados nas propriedades reológicas e mecânicas de concretos autoadensáveis (CAA). Para isso, foram analisadas quatro composições distintas de CAA, sendo uma delas produzida apenas com agregados naturais. As demais misturas utilizaram agregados miúdos e/ou graúdos reciclados em substituição aos agregados naturais, no teor de 20%, em massa. Também foi realizada a caracterização reológica da pasta de cimento e das argamassas destinadas à produção do CAA, por meio de reometria rotacional. A caracterização reológica de pastas, argamassas e concretos é uma maneira de avaliar o comportamento destes compósitos no estado fresco, podendo prover informações úteis que auxiliarão no processo de dosagem e controle de qualidade. As propriedades do concreto fresco foram avaliadas mediante os ensaios de espalhamento, tempo de escoamento t 500 e no funil V, habilidade passante e resistência à segregação. No estado endurecido foram determinadas as resistências à compressão, à tração por compressão diametral e módulo de elasticidade estático. Por meio dos resultados obtidos foi possível constatar perda de fluidez nas argamassas e concretos que empregaram agregados reciclados. Por outro lado, não foi verificada redução significativa nas propriedades mecânicas dos concretos produzidos com 20% de agregados graúdos ou miúdos reciclados.Palavras-chave: concreto autoadensável, agregados reciclados, resíduos de construção e demolição, reologia. ABSTRACTRecycling of mineral fraction of construction and demolition wastes (CDW), in form of aggregates, is seen as an alternative to reduce environmental impacts caused by construction. Recycled aggregates present higher water absorption and lower mechanical resistance and density when compared to natural ones, which will influence the properties of the produced concretes. The aim of this study was to investigate the influence of recycled aggregates in the rheological and mechanical properties of self-compacting concrete (SCC). For this, four distinct compositions of SCC were analyzed, one of them being produced only with natural aggregates. The other mixtures used fine and/or coarse recycled aggregates instead of natural aggregates, at 20% by mass. It was also carried out the rheological characterization of cement paste and mortars destined to SCC production, through rotational rheometry. The rheological characterization of pastes, mortars and concretes is a way to evaluate the behavior of these composites in fresh state, providing useful information that will aid in mix design process and quality contr...

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“…Recently, there was a shift in the direction of the research concerning recycled aggregates focusing more on RFA made with glass, lightweight materials, etc. The reason is that these studies [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] recommended not to include CDW as RFA anymore just on the basis of its functional properties. For that reason, in this study, the applicability of RFA in concrete in terms of all parameters (quality, environmental impact, energy consumption, toxicity and cost) was considered.…”

Section: Introductionmentioning

confidence: 99%

A Critical Review on the Influence of Fine Recycled Aggregates on Technical Performance, Environmental Impact and Cost of Concrete

Hafez

Kurda

et al. 2020

Applied Sciences

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The aim of this critical review is to show the applicability of recycled fine aggregates (RFA) in concrete regarding technical performance, environmental impact, energy consumption and cost. It is not possible to judge the performance of concrete by considering one dimension. Thus, this study focussed on the fresh and hardened (e.g., mechanical and durability) properties and environmental and economic life cycle assessment of concrete. Most literature investigated showed that any addition of recycled fine aggregates from construction and demolition waste as a replacement for natural fine aggregates proves detrimental to the functional properties (quality) of the resulting concrete. However, the incorporation of recycled fine aggregates in concrete was proven to enhance the environmental and economic performance. In this study, an extensive literature review based multi criteria decision making analysis framework was made to evaluate the effect of RFA on functional, environmental, and economic parameters of concrete. The results show that sustainability of RFA based concrete is very sensitive to transportation distances. Several scenarios for the transportation distances of natural and recycled fine aggregates and their results show that only if the transportation distance of the natural aggregates is more than double that of RFA, e the RFA based concrete alternatives would be considered as more sustainable.

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Performance of self-compacting concrete incorporating recycled concrete fines and aggregate exposed to sulphate attack

Cited by 88 publications

References 28 publications

Sustainable Concrete Application in the Manufacture of University Urban Furniture

Sustainable Concrete Application in the Manufacture of University Urban Furniture

Influência dos agregados reciclados nas propriedades reológicas e mecânicas do concreto autoadensável

A Critical Review on the Influence of Fine Recycled Aggregates on Technical Performance, Environmental Impact and Cost of Concrete

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