Alternative small-scale accelerated test to measure the effect of thermal shock on rendering mortar properties

Abstract

This article proposed an alternative small-scale accelerated test to measure the effect of thermal shock on rendering mortar properties. First, the temperature variation during the heating and cooling period was analyzed. Furthermore, two cooling setting conditions were evaluated. The final configuration of the accelerated test was applied to six mortar mixtures after 28 days of curing. The main property affected by the thermal shock was the length change of prismatic specimens. The other properties (capillary coefficient, tensile and compressive strengths, dynamic modulus of elasticity, and electrical resistivity) of the rendering mortars were affected by about 10%–30%. The thermal expansion coefficients found were consistent with the literature. Also, the tensile thermal stress values estimated from a theoretical model were greater than the tensile strength values of the mortars, indicating the tendency of internal cracking of the material.