Exposure of Mortars Modified with Rubber Aggregates and Polymer Admixtures to Acid Environments and Elevated Temperature Conditions

Abstract

The aim of the present paper was to study the effect of incorporating rubber aggregates and acrylic or EVA polymers on the properties of cement mortar exposed to acid (HCl, H2SO4, HNO3) and elevated temperature conditions. Compressive and bending strength tests, water absorption test, mass measurements, and visual inspection were performed. Impact-echo and impedance spectroscopy methods were used to investigate the effect of heat exposure. The use of rubber aggregates led to reduction of strength values and water absorption. The use of polymeric admixtures further decreased water absorption and inhibited compressive strength loss and delayed mass loss when the specimens were stored in acid solutions. The acoustic and electric measurements showed that the use of rubber aggregates or both rubber aggregates and polymers led to reduction of absorption frequency or relative permittivity, respectively. The drop of frequencies was attributed to the formation of microcracks, as well as to decomposition and brittleness of rubber aggregates and polymers. The elevated temperatures resulted in permittivity reduction. The final stage observed after heating at 400°C was the carbonization of the used polymers.