Performance and durability of self-compacting mortar with recycled sand from crushed brick

Abstract

The demolition of brick masonry structures and the rejected non-conform bricks are generating a great volume of brick residues. The use of recycled sand from brick residues in the production of mortar could decrease the amount of waste going into landfills and reduce the consumption of natural resources. This paper investigated the feasibility of using recycled sand from crushed brick (RBS) in the self-compacting mortar (SCM). The crushed limestone sand was partially replaced with RBS at different levels (0, 5, 10, 25 and 50%). The properties at fresh state, mechanical behavoir, drying shrinkage and durability of SCM were discussed. As the substitution of limestone sand by RBS increased, the compressive strength of mortars slightly reduced at the age of 28 days (3.3% and 16.9% lower than the reference mortar, respectively for 25% RBS and 50% RBS content); however, which is within the compressive strength requirement in European standard EN 998-2 for masonry mortars. The incorporation of RBS in SCM showed better resistance to chloride diffusion, whereas more attention should be paid to carbonation and sulphate attack. The results indicate that it is possible to manufacture SCM by partially replacing the crushed limestone sand with RBS up to 25% replacement level.