Study of mechanical and durability properties of mortars using slate waste

This study was focused on the addition of slate waste to Portland cement to evaluate the potential utilization as a mineral addition. The physical characterization of the residues was done by granulometric analysis and X-ray diffraction. The pozzolanic activity was evaluated by electrical conductivity, modified Chapelle, Luxan method and thermogravimetric analysis. Cement pastes and mortars produced with only Portland cement and with 14% addition of slate residues were evaluated by: capillarity, water absorption, Le Chatelier expansion, porosity, accelerated carbonation, compressive and tensile strength tests, and modulus of elasticity. The results showed that the residues have a high level of SiO2, however they do not present pozzolanic activity. Cement composites formulated with slate residues showed increase or maintenance of the mechanical properties and contributed to a significant increase in the parameters indicative of durability. It was also verified that such analyses have not yet been reported in the literature.