Self-levelling mortar with addition of marble and granite waste: physical and mechanical properties

Abstract

Self-levelling mortars for subfloors were produced with marble and granite cutting waste (40% and 50% MGCW addition to the cement mass), and without the residue, varying the amounts of viscosity modifying additive and superplasticiser, water/cement ratio and cement/sand ratio. Dosages were tested with limestone filler instead of MGCW, with the addition of polypropylene fibres, and a commercially available product was studied. Properties in the fresh state (initial flow, healing time, flow retention after 20 and 30 min. and setting time), and hardened (specific mass, water absorption, void content, compressive strength and flexural traction strength) were tested according to ASTM 1708. The optimised mixture with 50% MGCW, 0.55 water/cement factor, 1: 1.5 cement/sand ratio (by mass using CPV-ARI cement) achieved a compressive strength of 38.89 ± 2.10 MPa at 28 days, presenting the best performance among the mortars tested. The addition of fine material in the self-levelling mortar dosages contributed to the spreading of the material and mitigated the segregation problem. When used in self-levelling mortar mixtures, MGCW reduces the environmental impact of the exploration and processing of ornamental rocks.

Keywords:
Self-levelling mortar; Marble and granite cutting waste; Limestone filer; Polypropylene fibres; Mechanical properties