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Authors
Abstract(s)
O betão é um dos materiais mais amplamente utilizados no setor da construção e um dos que mais contribui para o seu impacte ambiental. Este contributo deve-se em grande parte ao facto de na sua produção ser tradicionalmente utilizado cimento Portland, que por sua vez é produzido com elevados consumos de energia e emissões de CO2.
É com o objetivo de encontrar uma alternativa viável à utilização de cimento que se enquadra o presente trabalho, que pretende essencialmente verificar a possibilidade de se utilizarem cinzas de fundo resultantes da incineração de resíduos sólidos urbanos, em detrimento do cimento, conseguindo reduzir o impacte inerente ao uso do betão como material de construção.
Desta forma, a campanha experimental laboratorial consistiu na análise das propriedades dos betões auto-compactáveis, produzidos com misturas binárias de cimento e cinzas de fundo resultantes da incineração de resíduos sólidos urbanos (CFRSU), no seu estado fresco (auto-compactabilidade) e no estado endurecido (comportamento mecânico e durabilidade). Para tal foram produzidas quatro amassaduras de betão auto-compactável (BAC), de acordo com a NP EN 206-9 (2010), que pretendem abranger uma gama alargada de substituição de cimento pela adição em estudo (20%, 30%, 40% e 50%). De forma a que seja possível realizar uma análise comparativa de resultados das amassaduras referidas, foi produzida uma quinta amassadura de BAC com incorporação de cinzas volantes para a percentagem de substituição de cimento de 30% que funcionará como betão de referência.
Assim sendo, foi avaliado o desempenho, em todas as vertentes, dos betões para as diferentes razões de substituição de cimento.
Ao analisar os resultados obtidos, verifica-se que a utilização de CFRSU contribuiu para o decréscimo das propriedades do BAC, tendo as misturas produzidas apresentado um desempenho inferior ao do betão de referência. Ainda assim, os resultados obtidos demonstram indicadores promissores no que respeita à durabilidade da mistura com 20% de substituição, com valores muito semelhantes aos de referência.
Concrete is one of the most widely used materials in the construction industry and one of the largest contributors to the environmental impact of the sector. This contribution is due in large part to the fact that Portland cement has been traditionally used in the production of concrete, which in turn is produced with high energy consumption and CO2 emissions. With the purpose of establishing a viable alternative to the use of cement, the main objective of this study is to verify the possibility of using bottom ash resulting from the incineration of municipal solid waste as a partial cement replacement, reducing the environmental impact associated with the use of concrete as a building material. The laboratory experimental campaign consisted in the analysis of the properties of the self-compacting concrete produced with binary mixtures of cement and bottom ash from municipal solid waste incinerators, in their fresh state (self-compactability) and in the hardened state (mechanical properties and durability). For this purpose, four self-compacting concrete mixes were produced according to NP EN 206-9 (2010), which are intended to cover a wide range of cement replacement by the aforementioned addition (20%, 30%, 40% and 50%). In order to make a comparative analysis of the results of the mentioned mixtures, a fifth self-compacting concrete mixture with fly ash incorporation was produced with a cement substitution of 30%, acting as reference concrete. Therefore, the concrete performance for different mixtures of cement substitution were evaluated in all aspects. When analyzing the obtained results, it is verified that the use of bottom ash from municipal solid waste incinerators contributed to the decrease in the properties of self-compacting concrete, with the mixtures produced having a lower performance than the reference concrete. Nevertheless, the results obtained show promising indicators regarding the durability of the mixture with 20% substitution, with values very similar to those of reference.
Concrete is one of the most widely used materials in the construction industry and one of the largest contributors to the environmental impact of the sector. This contribution is due in large part to the fact that Portland cement has been traditionally used in the production of concrete, which in turn is produced with high energy consumption and CO2 emissions. With the purpose of establishing a viable alternative to the use of cement, the main objective of this study is to verify the possibility of using bottom ash resulting from the incineration of municipal solid waste as a partial cement replacement, reducing the environmental impact associated with the use of concrete as a building material. The laboratory experimental campaign consisted in the analysis of the properties of the self-compacting concrete produced with binary mixtures of cement and bottom ash from municipal solid waste incinerators, in their fresh state (self-compactability) and in the hardened state (mechanical properties and durability). For this purpose, four self-compacting concrete mixes were produced according to NP EN 206-9 (2010), which are intended to cover a wide range of cement replacement by the aforementioned addition (20%, 30%, 40% and 50%). In order to make a comparative analysis of the results of the mentioned mixtures, a fifth self-compacting concrete mixture with fly ash incorporation was produced with a cement substitution of 30%, acting as reference concrete. Therefore, the concrete performance for different mixtures of cement substitution were evaluated in all aspects. When analyzing the obtained results, it is verified that the use of bottom ash from municipal solid waste incinerators contributed to the decrease in the properties of self-compacting concrete, with the mixtures produced having a lower performance than the reference concrete. Nevertheless, the results obtained show promising indicators regarding the durability of the mixture with 20% substitution, with values very similar to those of reference.
Description
Dissertação de natureza científica na área de Especialização de Edificações para a obtenção do grau de mestre em Engenharia Civil
Keywords
Betão auto-compactável Self-compacting concrete Resíduos sólidos urbanos Municipal solid waste Cinzas de fundo Bottom ash
Citation
LEITÃO, Joel Ricardo Cavaco - Misturas binárias de betão auto-compactável com incorporação de cinzas de fundo resultantes da incineração de resíduos sólidos. Lisboa: Instituto Superior de Engenharia de Lisboa, 2018. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa