Thermo-physical characterization of mortars made with uncontaminated marine sediments

Abstract

In a context of sustainable development, civil engineering must increasingly use recyclable materials to preserve natural resources. Sediments could be a solution in the context of their recovery in several areas. Uncontaminated marine sediments were used to partially substitute sand aggregate in mortars formulation. Physical, chemical, mineralogy and mechanical characterization were carried out to investigate their possible use and impact in cemented-based materials. Five mortars were studied with different percentage of sand substitution. The effect of sediments on the mechanical and thermo-physical properties were assessed.

This paper focus on the characterization of the thermo-physical properties. The mortars hydration kinetics were investigated at different temperatures. The acceleration of the chemical reactions was also assessed through the determination of the apparent activation energy of mortars. The thermal conductivity and the specific heat capacity were also evaluated. The measured heat released of mortars raise with the increase of sediment content. This result suggests an additional chemical activity linked to the presence of sediments within the matrix. The thermal conductivity of mortars decreased while the specific heat capacity increased with the percentage of sand replacement. This can be attributed to the high porosity and low density of the sediment mortars.