The Effect of the Calcined Dam’s Mud as Supplementary Cementitious Materials on Thermal Insulation

Abstract

In Algeria, the calcined dam's mud is a local renewable waste that proved its use as a supplementary cementitious material (SCMs) with similar mechanical performances and better resistance to several physical and chemical attacks than Portland cement. In the same context, the main objective of the work is to evaluate the effect of this calcined mud on thermal conductivity, which was never tested. To concretize this goal, one mortar based on control cement (CEMI) and three others based on modified cement by replacing CEMI by 10% to 30% Wt rates with the calcined mud of Chorfa dam have been prepared and cured before being put to the test procedure. Compressive strength, apparent density, water absorption after immersion, and thermal conductivity at three degrees of saturation state (saturated, outdoors, and dried state) were tested. The results show that using 10% to 20% replacement rate is characterized by good free lime and calcium hydroxide consumption that produces C-S-H gel, fills pores, decreases porosity, and increases density. The thermal conductivity of mortars based on the calcined mud in all states was lower compared than the control mortar, at saturated state by 16.28%, 17.83%, and 18.60% for the mortars 10%, 20%, and 30% (of cement replacement) respectively, at outdoors state by 5.5%, 4%, and 17.5% and dry state with 8.39%, 20.65%, and 38.07%. 10% to 20% mud replacement is beneficial for use in masonry and plastering wall applications of a building's envelope. 30% replacement rate can be developed and used in environments with minimal class expositions.