Post-fire residual properties of GFRP reinforced concrete slabs: A holistic investigation

Abstract

This paper provides critical data regarding the post-fire residual strength of Glass Fibre Reinforced Polymer (GFRP) reinforced concrete slabs. The residual tensile and bond strength of three types of GFRP reinforcing bars and the post-fire residual strength of a GFRP reinforced concrete slab are examined. For residual tensile strength, GFRP bars with a nominal diameter of 16 mm are exposed to temperatures up to 450 °C and tested after 24 h at room temperature. After 24 h, the specimens are loaded to failure at room temperature. For residual bond strength, pullout specimens are heated under various sustained load values. Finally, a full-scale GFRP reinforced concrete slab is tested at room temperature to evaluate the post-fire residual capacity after exposure to three hours of a standard fire. The residual tensile test results show that the bars that were exposed to 400 °C recovered at least 45% of the original strength while the residual bond strength is approximately 40% for pullout specimens that had experienced 300 °C. The post-fire residual strength of the slab is 68% of its room temperature flexural design strength with the bond loss at the ends of the slab being the governing mode of failure.