THE HYDROCHLORIC ACID EFFECTS ON MODIFIED CEMENT WITH NEW COMBINATIONS BASED ON CALCINED DAM’S MUD AND NATURAL POUZZOLANA

Abstract

Reducing the amount of clinker in cement industry using Supplementary Cementitious Materials (SCMs) is one of the solutions developed by researchers in our field trying to respect environmental requirements, in the same context the present work aim to test the feasibility of new combinations using two sorts of Algerian SCMs and to evaluate their behavior while exposed to hydrochloric acid. To concretize this objective we fabricated a control mortar (based on cement CEMI) and nine other mortars containing modified cements, by a binary and ternary mixtures of Portland Cement CEMI, Calcined Mud (Wastes) of Chofa Dam (CW) and Natural Pouzzolana (NP), all these mixtures were tested at fresh state for consistency and setting time of pastes, and at hardened state for apparent density measure, water absorption and compressive strength of mortars. After that the ten of them were immersed in hydrochloric acid (HCL) 5% during fifteen weeks (105 days), Then they were examined for mass loss, volume loss, density decrease (apparent density) and the visual appearance. The results obtained in the majority of tests showed that the mixtures containing SCMs especially the ternary mixtures are realizable and more advantageous than others and characterized by a higher water demand and a better behavior after both compressive and HCL attack.