Influences of temperature and opening rate of substrate cracks on the mechanical behaviour, crack–bridging ability and deformation mechanisms of one–component, cementitious, flexible waterproofing membranes

Abstract

One–component, cementitious, flexible waterproofing membranes bridge cracks because their polymer-dominated matrix takes up the deformation. The sensitivity of the deformation of polymers to temperature and strain rate raises interest to the influence of these two parameters on the crack–bridging ability of the waterproofing membranes. Temperature–controlled crack–bridging and dog-bone experiments with in–situ monitoring of the sample's surfaces show a decrease in the crack–bridging ability (CBA) of the waterproofing membranes and a decrease in plastic deformation at testing temperatures above the glass transition temperature (Tg) of the used polymer. At temperatures below the Tg, the membranes deform in a brittle manner. Rate–controlled crack–bridging and dog-bone tests with in–situ monitoring of the sample's surfaces reveal a decrease in crack–bridging ability and plastic deformation with decreasing displacement rate. Hence, temperature and displacement rate are crucial parameters governing the crack-bridging performance of waterproofing membranes.