An Experimental Study on the Dynamic Mechanical Properties of Epoxy Polymer Concrete under Ultraviolet Aging

Epoxy polymer concrete (EPC) is widely applied in engineering for its excellent mechanical properties. The impact loads and severe climatic conditions such as ultraviolet radiation, temperature change and rain erosion are in general for its engineering practice, potentially degrading the performance of EPC. In this paper, a procedure of accelerated aging for EPC, imitating the aging effect of ultraviolet radiation and hygrothermal conditions based on the meteorological statistics of Guangzhou city, was designed. After various periods of accelerated aging, the dynamic behaviors of EPC were studied by using a Split Hopkinson Pressure Bar (SHPB). The verification of the experimental data was performed. The two-stage dynamic compression stress-strain curves were obtained: (a) linear growth stage following by strain hardening stage at impact velocity 12.2 m/s and 18.8 m/s, (b) linear growth stage and then a horizontal stage when impact velocity is 25.0 m/s, (c) linear growth stage following by strain softening stage at impact velocity 29.2 m/s. The experimental results show that the specimens after longer accelerated aging tend to be more easily broken, especially at impact velocity 12.2 m/s and 18.8 m/s, while the strain rate is the main factor affecting the compression strength and stiffness. Ultimately the influence of strain rate and equivalent aging time on dynamic increase factor was revealed by a fitting surface.