环氧基GFRP筋在海水海砂混凝土孔溶液环境下的损伤演化试验与模型研究  

Experimental and modelling studies on damage evolution of epoxy-based GFRP bars in pore solution environment of seawater sea-sand concrete

作　　者：赵齐 张大旭[1,2,3] 赵晓林 王文华 Zhao Qi;Zhang Daxu;Zhao Xiaolin;Wang Wenhua(School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure,Shanghai Jiao Tong University,Shanghai 200240,China;The Hong Kong Polytechnic University,Hong Kong 999077,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]上海交通大学海洋工程国家重点实验室,上海200240 [3]上海交通大学上海市公共建筑和基础设施数字化运维重点实验室,上海200240 [4]香港理工大学,中国香港999077

出　　处：《土木工程学报》2022年第9期25-41,共17页China Civil Engineering Journal

基　　金：国家自然科学基金(12072192);上海市自然科学基金(20ZR1429500)。

摘　　要：为研究环氧基玻璃纤维增强聚合物(GFRP)筋在海水海砂混凝土(SWSSC)孔溶液环境下的损伤演化机理与性能退化规律,对其进行溶液浸泡加速腐蚀、静力拉伸、扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)和能谱仪(EDS)等检测试验,并与相同基体的碳纤维增强聚合物(CFRP)筋进行对比分析,得到环氧基G/CFRP筋在SWSSC孔溶液中的强度和弹性模量的退化规律,对比G/CFRP筋腐蚀损伤机理,提出基于氢氧根离子蚀刻速率的损伤演化理论公式,并建立相应有限元模型。结果表明:环氧基G/CFRP筋的抗拉强度随浸泡时间和孔溶液温度的增加而降低,当FRP筋的强度保留率高于80%时,其弹性模量的保留率在95%以上;环氧基GFRP筋的腐蚀损伤主要由环氧基体交联结构的水解、界面相的失效以及玻璃纤维蚀刻引起,而环氧基CFRP筋主要发生基体和界面相的破坏,碳纤维不受腐蚀。基于氢氧根蚀刻速率的损伤模型能够较准确地预测FRP筋在SWSSC孔溶液环境下的蚀刻深度和抗拉强度。To study the damage evolution mechanisms and property degradation of epoxy-based glass fiber-reinforced polymer(GFRP) bars in pore solution environment of seawater sea-sand concrete(SWSSC),accelerated corrosion tests immersing in solutions,statically tensile tests,scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR) and energy dispersive spectrometer(EDS) experiments of GFRP bars were carried out.The test results were compared with those of carbon fiber-reinforced polymer(CFRP) bars with the same matrix.The degradation laws of tensile strength and elastic modulus of G/CFRP bars immersed in pore solution of SWSSC were obtained and their corrosion damage mechanisms were compared.A hydroxyl ion etching rate-based method was proposed and its finite element model was established.The results indicate that the tensile strength of epoxy-based G/CFRP bars decreases as the immersion time and the temperature of SWSSC increase.The elastic modulus of epoxy-based G/CFRP bars retain more than 95% of their initial values when their tensile strength retentions are higher than 80%.The corrosion damage of epoxy-based GFRP bars is mainly induced by the hydrolysis of cross-linked structures of epoxy matrix,the corrosion of fiber-matrix interphase,and the etching of glass fibers.However,the corrosion damage of epoxy-based CFRP bars is onlycaused by the corrosion of epoxy matrix and fiber-matrix interface,while carbon fibers are not corroded.The hydroxyl ions etching rate-based model can accurately predict the etching depth and tensile strength of FRP bars in the pore solution environment of SWSSC.

关 键 词：FRP复合材料 海水海砂混凝土 加速腐蚀 损伤机理 数值模拟 

分 类 号：TU599[建筑科学—建筑技术科学]