Desempenho em termos de durabilidade de betões com cinza de fundo de resíduos sólidos ativada alcalinamente

22/11/2022

In this dissertation, the performance in terms of durability of alkali-activated concrete (AAC) was studied. These mixes were composed of fly ash (FA) and municipal solid waste incinerator bottom ash (MIBA), which can be used as substitutes of Portland cement (OPC) The performance of these mixes was also evaluated in terms of the influence of replacing natural aggregates (NA) with recycled aggregates (RA). OPC was replaced in its entirety in four different concretes, where the percentages of CV were 100, 75, 50 and 25% and those referring to CFRSU were 0, 25, 50 and 75%, respectively, and these were produced with 100% AN. Another four mixes were produced by replacing the entire NA fraction (both coarse and fine aggregates) with RA with equivalent grading, with the same FA and MIBA replacement ratios as above. Two mixes were produced with 100% OPC, one with NA and the other with RA, to be tested as the reference mixes. During the experimental campaign, it was noted that, with increasing use of MIBA, the specimens presented a decline in performance. An improvement was observed for shrinkage, however, for concrete produced with RA, this tendency was not noticed since part of the ACC containing MIBA presented significant expansion (there was an expansion of 90 µm/mm for concrete with 75% of MIBA). A large improvement in compressive strength was also noted in AAC specimens after a curing process in a CO2 chamber, presenting an increase of 14.9 MPa in mixes with 25% FA and 75% MIBA.

Autores da comunidade :

• 

  F

  Filipe Sequeira Alves Miguel

  ist186840

Orientadores desta instituição:

• 

  J

  Jorge Manuel Caliço Lopes de Brito

  ist12299

• 

  R

  Rui Vasco Pacheco Santos da Silva

  ist156561

- Engenharia Civil

- Português

Instituto Superior Técnico