The Improvement of the Tensile Behavior of CFRP and GFRP Laminates at Elevated Temperatures Using Fire Protection Mortar

In spite of many benefits, FRP materials are susceptible to elevated temperatures. On the other hand, because FRP laminates are different from other FRP materials, data acquired from investigations concerning FRP materials cannot be suggested for FRP laminates. An assessment of the tensile performance of fibers impregnated by epoxy resin as binder is needed. In recent decades, many methods have been presented to protect fiber reinforced polymer (FRP) composites against high temperatures. The application of fire protection mortar is a low-cost and easy technique among all methods. In this investigation, the influence of fire protection mortar on the improvement of the tensile strength of glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) laminates was evaluated. For this object, over 200 FRP laminates with or without fire protection mortar were tested at various elevated temperatures. Investigated temperatures varied from 25°C to 500°C. According to the results obtained from this study, the strength of FRP laminates considerably reduced following the laminates experienced the temperatures higher than 400°C. However, the samples covered with fire protection mortar underwent lower the tensile strength decrements. Eventually, a linear model was presented to estimate the strength of FRP laminates including or excluding protective mortar at elevated temperatures on the basis of linear regressions carried out on test data.