玻璃纤维复材筋拉伸性能温度效应试验研究

EXPERIMENTAL STUDY OF TEMPERATURE EFFECT ON TENSILE PROPERTIES OF GFRP BARS

玻璃纤维复材(GFRP)筋拉伸性能的温度效应十分明显,特别是高温环境下其性能变化规律在工程应用中需要重点关注。以GFRP筋直径、温度值高低、温度升高方式和恒温时间等为变化因素,通过试验研究温度效应下GFRP筋拉伸力学性能的变化规律。研究结果表明:随着温度升高,GFRP筋极限抗拉强度和极限应变下降较明显,而高温作用对GFRP筋的弹性模量影响较小。高温下直径16 mm的GFRP筋的极限抗拉强度和弹性模量比直径22,25 mm的高。温度低于240℃的情况下,经恒高温作用后筋体的极限抗拉强度比未经恒高温作用的同温度下的筋材略有增加,高于240℃后两种筋材的极限抗拉强度无明显差异。当恒高温作用时间不超过1 h时,GFRP筋力学性能较为稳定。

The tensile properties of Glass Fiber Reinforced Polymer（GFRP） bars changes apparently under temperature effect,its change law should be paid attention seriously in engineering application,especially in high temperature environment.GFRP bar diameter,temperature value,heating mode and constant temperature time and other factors were considered,and the temperature effect on the tensile mechanical properties of GFRP bars was studied through tests.The results showed that the ultimate tensile strength and the ultimate strain decreased significantly with the increase of temperature,while the effect of high temperature had less influence on elastic modulus of GFRP bars.At high temperatures,the ultimate tensile strength and elastic modulus of the GFRP bar with16 mm was higher than the GFRP bar with 22 mm and 25 mm.When the temperature was below 240 ℃,the ultimate tensile strength of bars under the action of constant high temperature slightly increased compared with the bars without constant high temperature processing; when the temperature was above 240 ℃,there was no obvious difference between these two kinds of bars.When the constant temperature time was not more than one hour,the mechanical properties of GFRP bars were relatively stable.