玻璃纤维增强筋在低温环境中的拉伸性能研究

摘要

分别将直径为16、22 mm的玻璃纤维增强(GFRP)筋在不同温度下进行拉伸试验,研究了温度、筋体直径、恒温时间等因素对GFRP筋拉伸性能的影响,揭示了其拉伸性能的变化规律.结果表明,在低温环境下,GFRP筋体破坏表观特征无明显变化;在-20～0℃时,筋体极限拉伸强度随温度的降低而增加,直径为16 mm的GFRP筋的拉伸模量随温度的降低变化明显,而直径为22 mm的GFRP筋则呈现较稳定的状态;在0～20℃时,2种筋体的极限拉伸强度和拉伸模量均变化较小;低温状态下恒温1h后,筋体的拉伸性能趋于稳定,低温持续时间对筋体的影响较小.%A tensile experiment was conducted at different temperatures for glass fiber-reinforced polymer(GFRP) bars using glass fibers with diameters of 16 mm and 22 mm.The effects of environmental temperature,fiber diameter and constant temperature time on tensile properties of GFRP bars were investigated.The results indicated that the GFRP bars did not show a significant change in apparent failure characteristics under the low-temperature environment,and their ultimate tensile strength increased with a decrease of temperature in the range of-20～ 0 ℃.Furthermore,the modulus of GFRP bars containing fibers with a diameter of 16 mm was reduced with a decrease of temperature,whereas that with a diameter of 22 mm maintained a stable value.However,these two types of GFRP bars presented little change in the temperature of 0～20 ℃.The mechanical properties of GFRP bars tended to be stable after being kept in a low temperature for 1 h.The constant temperature time almost showed no effect on the bars.