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

Abstract

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 °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 °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 °C but still retained 41% of its original strength at 800 °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.