34
DO1:10.7672/sgjs2013100034
施工技术
CONSTRUCTION TECHNOLOGY
2013年5月下第42卷第10期
浸水环境下FRP-混凝土界面剪切黏结性能研究
张大伟，金伟良”，JustinShrestha，UedaTamon
（1.浙江大学结构工程研究所，浙江杭州310058： 2.北海道大学北方围环境政策工学专攻，札规）
【摘要】采用单搭接头剪切试验比较FRP-混凝土界面使用不同树脂黏结剂在不同浸水时长下的剪切黏结强度、破坏模式、剪切断裂能、黏结滑移曲线等黏结待性。最大6个月的20℃没水试验表明，采用多乙烯多胺混合硬化树脂的界面黏结强度降低了11%~14%，采用多胺硬化树脂的界面黏结强度降低了2%~10%，黏结层断裂能和局部最大剪应力也有所降低。浸水后的界面破坏模式由浸水前的混凝土黏聚层转移为界面黏着层，这表明浸水条件下界面黏着力降低。同时，树脂黏结材料的材料试验结果表明，树脂本身的抗拉强度在浸水6个月后有所提升，而剪切黏结强度只有微小降低。局部黏结滑移关系的计算结果表明浸水后最大局部剪切应力有所降低，同时界面的平均剪切断裂能降低26%。
【关键词】混土；FRP；浸水环境；黏结强度；树脂
【中图分类号】TU599
【文献标识码］A
[文章编号】1002-8498(2013)10-0034-05
Influence of Water on Shear Bond Properties of
FRP-concrete Interfaces
Zhang Dawei'，Jin Weiliang',Justin Shrestha",UedaTamon
(1. Institute of Structural Engineering, Zhejiang University, Hangzhou,Zhejiang 310058, China; 2. Department of Engineering and Policy for Sustainable Environment, Hokkaido Unisersity, Sapporo)
Abstract : Single lap shear bond test was conducted to compare the ultimate bond strength, failure modes, fracture energy, bond stress-slip curves with and without water immersion at different exposure periods and epoxy primers. The results until 6 months exposure period revealed that bond strength decreased around 11% ~ 14% for Type-E (polyphenol-polyamine combined hardener epoxy resin) specimens and 2% ~ 10% for Type-F (polyamine hardener epoxy resin） specimens when subjected to continuous immersion in water at 20C. The study also observed that decrease fracture energy and peak bond stress after water immersion. Further, the bond failure of'FRP-concrete interface occurred at the primer-concrete layer showing loss in adhesion properties after exposure in water. In addition to this, material test were also conducted to determine the effect of water on the mechanical properties (tensile, shear, Young's modulus) of resins used. The tensile strength of the resins after water immersion were found higher in most of the cases irrespective of period of immersion whereas the shear test of the resins showed little decrease in strength after six months of continuous immersion. Both the peak shear stress and fracture energy decreased with increasing immersion period.
Key words;concrete;FRP; water immersion; bond strength;epoxy
外部水分可以通过多种途径或作用到达FRP-混凝土复合材料的界面，例如沿FRP纵向纤维的毛细虹吸作用、沿混凝土裂缝和内部孔隙的渗透作用等(1)。FRP材料一般具有较好的耐久性，但是有些
*浙江大学"紫金计划"资助项目（188020+1934326041/016）【作者简介］张大伟，副教授，E-mail：dwzhang@zju.edu.cn
【收稿日期】2013-04-15 万方数据
FRP材料在长期浸水条件下材料性能会发生劣化，主要体现在黏结环氧树脂材料的劣化。环氧树脂因其较好的抗腐蚀性、抗湿、抗高温等特性而被广泛应用于合成树脂材料3)。水分可以造成不同化学组成的环氧树脂的可逆或不可逆劣化。在树脂硬化增塑阶段，水分的劣化作用主要表现在破坏聚合物链之间的范德蒙黏结力，从而导致聚合物强