Desempenho em termos de resistência mecânica de betões com cinzas de fundo da incineração de resíduos sólidos urbanos ativadas alcalinamente

Gonçalo da Cruz Cagica

Key information

Authors:

Gonçalo da Cruz Cagica (Gonçalo da Cruz Cagica)

Supervisors:

Jorge Manuel Caliço Lopes de Brito (Jorge Manuel Caliço Lopes de Brito); Rui Vasco Pacheco Santos da Silva (Rui Vasco Pacheco Santos da Silva)

Published in

11/30/2022

Abstract

This dissertation presents a study of the mechanical performance of alkali-activated concrete, in which the binders used were fly ash and bottom ash from municipal solid waste. In order to create a 100% recycled concrete, 100% of natural aggregate was replaced by recycled aggregate. The main objective of this dissertation is to investigate the influence of the replacement of fly ash by bottom ash from municipal solid waste and the total replacement of natural aggregate by recycled aggregate. The specimens produced were submitted to a dry chamber curing and some had an additional curing in CO2 chamber, with the objective of verifying which influence on the performance of the resistant capacity. With the dry-cured specimens, compressive strength, modulus of elasticity, and tensile strength tests were performed. With the specimens cured in a CO2 chamber, compressive strength tests were performed. Analyzing the values obtained in the experimental campaign for the mixtures with natural aggregate, it was found that, with increasing replacement of fly ash, there was a worse performance in terms of compressive strength at 28 days. For the specimens with total replacement of natural aggregate by recycled aggregate, it was also found that, with increasing replacement of fly ash, the concretes showed worse performance in terms of compressive strength at 28 days, presenting percentage decrease values of ≈83-96% relative to the reference concrete.