Thermal expansion of epoxy and polyester polymer mortars—plain mortars and fibre-reinforced mortars

Abstract

The study was conducted in order to determine the coefficient of thermal expansion of two specific binder formulations of epoxy and unsaturated polyester polymer mortars. The variation of this parameter with temperature was also analysed. Polymer concrete and mortars have been observed to have lower coefficients of thermal expansion at lower temperatures than at higher temperatures. Plots of strains vs. temperature are often bilinear, indicating a sharp change in the coefficient of thermal expansion (International Congress on Polymers in Concrete, July 1995). To determine how this discontinuity varies for these two materials, specimens of both formulations were tested for several temperature ranges between −20 and 60 °C. In addition, to determine the influence of fibre reinforcements on thermal expansion of polymer mortars, epoxy polymer mortars reinforced with both carbon and glass chopped fibres were also tested for thermal expansion. It was concluded that, for both formulations, the variation of thermal expansion with temperature follows a parabolic law rather than a bilinear law. The reinforcement of chopped glass fibres (1%) has no significant effect on thermal expansion of epoxy polymer mortar, while the inclusion of carbon fibres (2%) on the same mortar formulation has a reducing effect on thermal expansion of this composite material for temperatures above room temperature.