Behavior of Glass Fiber-Reinforced Polymer Bar Coupons under Sustained Load and High Temperatures

Research presented herein is part of a program to study the effects of climate changes on fiber-reinforced polymer (FRP) reinforcement. This paper presents results of an experimental study on the tensile behavior of glass fiber-reinforced polymer (GFRP) bars under different loading and temperature conditions. In the conventional steady-state temperature tests, specimens were heated to a desired temperature, up to 250[degrees]C (482[degrees]F), and then loaded to failure. Tensile tests were also conducted under sustained constant stress or constant deformation conditions and subsequently heated to failure. The sustained stress levels varied from 40 to 90% of the bar strength at room temperature. Results showed that GFRP bars experienced approximately 60% reduction in strength at a steady-state temperature of 250[degrees]C (482[degrees]F). The bars subjected to 40% of room temperature strength and exposed to high temperatures resulting from situations such as sudden fire sustained the load for approximately 50 minutes. Keywords: glass fiber-reinforced polymer (GFRP) bars; high temperature; sustained loading; tensile strength; thermal degradation.