高温作用后GFRP/BFRP筋拉伸性能试验研究及强度折减计算  

Experimental study on the tensile properties and strength reduction calculation of GFRP/BFRP reinforcements after high-temperature treatments

作　　者：陆春华[1] 平安 延永东[1] 张菊连 LU Chunhua;PING An;YAN Yongdong;ZHANG Julian(Faculty of Civil Engineering Mechanics,Jiangsu University,Zhenjiang 212013,China;Shanghai Hongxin Construction Technology Co.,Ltd.,Shanghai 201800,China)

机构地区：[1]江苏大学土木工程与力学学院,江苏镇江212013 [2]上海宏信建筑科技有限公司,上海201800

出　　处：《哈尔滨工程大学学报》2023年第3期443-449,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51878319,51578267);江苏省“六大人才高峰”高层次人才选拔培养项目(2015-JZ-008).

摘　　要：为探讨高温作用后2类纤维增强复合材料(FRP筋材)的拉伸性能退化情况,本文对高温作用后的玻璃/玄武岩纤维增强复合材料(GFRP/BFRP)筋材进行了拉伸试验,并将宏观与微观结合进行分析。试验结果表明:高温超过220℃后,筋材表面部分纤维开始脱落,整体性逐渐遭到破坏,已不再适合进行拉伸试验;经220℃以内温度作用后,2类FRP筋材抗拉强度均随作用温度升高呈阶段性下降的趋势;而弹性模量总体变化幅度很小;高温作用后,直径16 mm的GFRP筋抗拉强度下降速率比12 mm的2种FRP筋更快;结合试验结果与扫描电镜微观结构分析,可认为高温作用后2类FRP筋抗拉强度退化的主要原因是树脂和纤维界面黏结性能的退化。结合本文和已有相关试验结果,提出了20~220℃温度范围内G/BFRP筋抗拉强度的折减计算模型,并给出了关键温度节点对应的强度保留率ηt建议值。To discuss the degradation of the tensile properties of two kinds of fiber-reinforced plastic(FRP)rein-forcements after high-temperature treatments,we conducted a tensile test of glass/basalt fiber-reinforced polymer(G/BFRP)reinforcements under high temperatures and analyzed them by combining macro and micro aspects.The test results show the following:When the high temperature exceeds 220℃,the test FRP bars are no longer suitable for tensile tests because some fibers on the surface of the bar begin to fall off,and the integrity is gradually damaged.After the high-temperature treatment within 220℃,the tensile strengths of G/BFRP reinforcements gradually de-crease with the increase in applied temperature,while the overall change range of the elastic modulus is very small.After a high-temperature treatment,the tensile strength of GFRP bars with a larger diameter of 16 mm decreases faster than those of two kinds of FRP bars with a 12 mm diameter.Combining the test results and scanning electron micros-copy analysis,it can be concluded that the main reason for the degradation of the tensile strength of two types of FRP bars after a high-temperature treatment is the degradation of the bonding properties between resin and fiber.Finally,on the basis of the test results of this study and some previous studies,we put forward a reduction calculation model of the tensile strength of G/BFRP reinforcements in a temperature treatment range of 20℃-220℃and provide some recommended values ofηt that reflect the strength retention at key temperatures.

关 键 词：火灾 高温作用 纤维增强复合材料直径 玻璃纤维增强复合材料 玄武岩纤维增强复合材料 微观分析 拉伸性能 强度计算 

分 类 号：TU502[建筑科学—建筑技术科学]