Material Characteristics of Glass Fibre Reinforced Polymer (GFRP) Bars at High Temperature

Abstract

The lack of adequate information on glass fibre reinforced polymer (GFRP) material characteristics at high temperatures lowers the accuracy of analytical and design models developed to predict the behaviour of GFRP reinforced concrete members. This paper presents experimental results of a series of tensile tests on GFRP bars at elevated temperatures. These results are a part of ongoing comprehensive material tests on various GFRP products from different manufacturers. Up until now, material tests conducted on GFRP bars have been limited to bars of up to 12 mm in diameter. To represent real fire situations in typical FRP reinforced concrete structures, two novel features have been implemented in the experimental program: large and commonly used GFRP reinforcements (#5 with nominal diameter of 16 mm), and tensile tests under transient temperature. Temperature ranges from 25 to 400ËšC have been considered for steady state temperature tests. In transient condition tests, specimens are loaded before heat exposure. For the transient temperature tests, bars loaded to service levels (75 kN) failed at temperatures above 500ËšC.