Coupled effect of temperature and impact loading on tensile strength of ultra-high performance fibre reinforced concrete

This study focused on coupled effect of temperature and impact loading on tensile strength of an ultra-high performance fibre reinforced concrete (UHPFRC), which retains 69% of its original compressive strength after exposure to 1000 degrees C. The relationship between tensile strength and compressive strength was investigated under the coupled action since temperature may have different effects on them. Static tests and dynamic tests using a self-designed Split Hopkinson Pressure Bar (SHPB) system were conducted at temperatures 20, 200, 400, 600 and 800 degrees C. Comparison was made between tensile strength and compressive strength of UHPFRC obtained in hot state and cooled-down state. It was found splitting tensile strength fell sharply beyond 400 degrees C but still retained 41% of its original strength at 800 degrees C, well above other concretes. Temperature and combined action of elevated temperature and impact loading have different effects on splitting tensile strength and compressive strength.