Effect of aggregate distribution and shape on failure behavior of polyurethane polymer concrete under tension

The effects of aggregate shape and distribution on the strength and fracture behavior of Polyurethane Polymer Concrete (PPC) are analyzed through a numerical approach. A 2D FE model is constructed in which aggregates are modeled by random distributed polygon, and interfaces are the areas surrounding each aggregate. The mechanical parameters of the polyurethane (PU) matrix and the bonding properties between the PU matrix and aggregate are experimentally determined. Compressive testing of the PPC specimens is firstly carried out to provide experimental benchmark for calibration of the proposed numerical model. Numerical simulations of the model with static tension are then carried out using thirty generated specimens and the tensile stress-strain curves are obtained. It is found that the aggregate shape and distribution have significant effects on the failure behaviors of the PPC specimen under loading, i.e. the micro-cracks formation, growth and the failure strength. Based on numerical analysis, a threshold value of the aggregate polygon meso-statistical parameter is recommended, under which the PPC material presents the best mechanical properties.