Análise de desempenho de argamassas com utilização de resíduos de construção e demolição de alvenaria como substituto parcial de agregado miúdo natural

Abstract

The negative impact of construction on the environment is known both for the production of the materials used as raw material and for the generation of solid waste during the construction and demolition processes. An alternative solution is the use of recycled aggregates. Despite the influence of the use of recycled aggregates already known in concrete and paving, in mortars there is still no consensus in the literature. This study proposes to evaluate the performance of rendering and bedding mortars with partial replacement of natural aggregates by recycled aggregates from three types of waste from building and demolition of masonry: ceramic block residue, mortar residue and mixed demolition residue. For analysis, mortars with 30% and 50% replacement of the natural aggregate with two traces were made, a weak 1: 6 for rendering and a strong 1: 3 for bedding, comparing with reference traces. Statistical analysis of the results was done using the ANOVA method and as a complement to the principal component analysis. To evaluate the rendering mortars were prepared walls rendered with the studied mixtures that were exposed in external environment and tests of resistance to adhesion and permeability were carried out. It was observed that there was an increasing tendency in the mechanical resistance of the mortars with the use of residues, however, only the mortars with 30% of the mortar residue proved to be more resistant than the others according to the ANOVA. For adherence, there was a behavioral differentiation according to the type of residue used, highlighting the ceramic block residue. ANOVA, however, indicated low variability of the results. For the permeability, the mixture with 50% of ceramic block was more permeable, according to statistical analysis, the others did not present significant variability among themselves. In order to evaluate mortar, in addition to mechanical strength analysis, a compression test of masonry prisms was performed, seated with the studied mixtures. The results of mechanical resistance indicated a decreasing trend with the use of residues, however, the statistical analysis indicated that there was no significant variation of the results, suggesting the low influence of the use of the residues for this property. Through the results, the applicability of the use of recycled aggregates for both coating mortar and settlement was confirmed.