Concrete cover requirements for FRP reinforced members in hot climates

Excessive corrosion problems exist in the Arabian Gulf countries. The exterior surfaces of reinforced concrete structures in these countries are subjected to high temperatures and humidity. Fiber Reinforced Polymer (FRP) bars are currently contending conventional steel in reinforced concrete members in highly corrosive environments or where non-magnetic fields are required. However, the difference in thermal expansion between FRP bars and the surrounding concrete may cause significant splitting stresses within the concrete around the bars during temperature increase. In this paper, the non-linear analysis of concrete members subjected to high temperatures ranging from 20 °C to 100 °C is discussed. Several design parameters are varied such as FRP type, bar diameter, concrete cover, and concrete strength. The results of the analytical study are substantiated by test results from ten FRP and steel reinforced concrete beam specimens subjected to high temperatures and vertically applied loads up to failure. The experimental program also included testing of 42 concrete cylinders reinforced with different types of FRP bars and subjected to high temperatures.