【摘要】 通过拉伸试验研究了高温后纤维增强聚合物(FRP)筋的纵向拉伸性能.试验参数包括温度、FRP筋直径、FRP筋种类和恒温时间.结果表明:室温下和高温后FRP筋拉伸应力-应变关系曲线相似;随着温度升高,FRP筋抗拉强度和极限应变逐渐下降;在试验温度范围内,高温作用对FRP筋的拉伸弹性模量影响较小;随着玄武岩纤维增强聚合物(BFRP)筋直径减小,高温作用后BFRP筋抗拉强度降低程度呈增加趋势;BFRP筋直径对弹性模量和极限应变的影响没有明显规律;高温作用对玻璃纤维增强聚合物(GFRP)筋的影响大于BFRP筋;270℃时FRP筋在0.5h前已完成大部分玻化、热分解反应.建议了300℃以内高温后FRP筋抗拉强度折减系数应取的值,当温度高于300℃时,BFRP筋和GFRP筋均不应使用.更多还原

【Abstract】 Through tensile tests,longitudinal tensile properties of fiber reinforced polymer(FRP)bars after high temperature were studied.Test parameters include temperature,FRP bar diameter,FRP bar type and constant temperature time.The results show that,the stress-strain relationship curves before and after high temperature are similar.The tensile strength and ultimate strain of FRP bars decline gradually as temperature rises.Within the range of test temperature,tensile modulus of elasticity is less affected by high temperature.With the decrease of FRP bars diameter,the tensile strength reduction ratio of BFRP bars appears to increase.The diameter of BFRP bars has no obvious influence on modulus of elasticity and ultimate strain.The high temperature resistance of BFRP bars is better than that of GFRP bars.When the temperature is at 270 ℃,FRP bars have finished most glass transition and thermal decomposition in the first half an hour.Finally,tensile strength reduction factor of FRP bars after high temperature was suggested to be under 300°C,when the temperature is higher than 300 ℃,BFRP bars and GFRP bars should not be used.更多还原