Durability of cement mortars containing fine demolition wastes as supplementary cementitious materials
Anna Tokareva, Danièle Waldmann
Abstract
The study addresses the durability performance of cementitious mortars containing 20 % recycled powders derived from construction and demolition waste, specifically concrete screenings, mixed screenings, and slurries from the washing of recycled aggregates. Uncalcined and thermally activated at 500°C, the powders were evaluated for their potential as supplementary cementitious materials. Key durability parameters analyzed include freeze-thaw resistance, fire resistance and sulfuric acid corrosion resistance, along with capillary absorption and drying shrinkage. Analysis of Variance (ANOVA) was used to assess the influences of various factors on the durability properties. The results demonstrate that the type of waste has a significant impact on the durability of mortars, with ceramic-containing specimens exhibiting superior performance in comparison to those comprising pure concrete powders. Capillary absorption emerged as an important factor for resistance to extreme temperatures. Furthermore, the findings of this study demonstrate that thermal activation of waste powders does not enhance the durability parameters, and that drying shrinkage shows no significant impact on durability. This study fills a knowledge gap in the durability of cementitious materials incorporating recycled powders and highlights the potential of ceramic-containing powders in sustainable cement production. • Durability properties of mortars with various CDW powders were investigated. • Thermal treatment of CDW powders at 500°C did not enhance the durability of mortars. • Ceramic particles in SCMs improve the durability properties of mortars. • Mortars with CDW powders exhibited higher capillary absorption than the reference mortar. • Thermal activation of CDW powders reduced the drying shrinkage of mortars.