Fire tests on full-scale FRP reinforced concrete slabs

The fire resistance of two concrete slabs reinforced completely with glass fibre reinforced polymer (GFRP) bars was experimentally investigated through a full-scale standard fire test. The Canadian standard on design of FRP reinforced buildings (CSA S806) currently requires 60 mm of clear concrete cover in a FRP reinforced concrete slab to ensure 2 h of fire resistance. The two concrete slabs, which were identical in every aspect except the types of GFRP reinforcing bars, were designed and fabricated with 60 mm concrete cover in this experiment to examine the fire resistance of the existing FRP reinforced concrete structures designed using CSA S806. The uniformly distributed loads were applied causing flexural moment of 45 kN·m, which was 55% of the ultimate moment resistance of the slabs at room temperatures, and sustained throughout the fire test. Both loaded slabs endured more than three hours of ASTM-E119 standard fire exposure. The results promised a more efficient and economic application of FRP reinforcing bars in concrete construction. The effects of concrete cover, unexposed length in providing adequate anchoring at the ends, and two different types of widely used GFRP reinforcing bar were studied in this research.