纳米改性环氧树脂增强CFRP-混凝土体系粘结及滑移性能研究

Study on bonding and sliding performance of nano-modified epoxy resin reinforced CFRP-concrete system

为研究TiO_(2)/有机蒙脱土(OMMT)/环氧树脂(EP)复合材料对CFRP-混凝土界面粘结及滑移性能的影响,对TiO_(2)/OMMT/环氧复合材料配比进行优化并将其应用于CFRP-混凝土体系的双搭接剪切实验。结果表明:在OMMT/EP复合材料中加入适量的纳米TiO_(2)可显著提高蒙脱土的剥离程度,当填料(TiO_(2)+OMMT)的质量分数为2%时,复合材料的拉伸强度、断裂伸长率以及冲击强度分别为纯环氧树脂的153.06%、159.09%和159.19%。作为胶粘剂用于CFRP-混凝土体系时,TiO_(2)/OMMT/EP复合材料增强了纤维与混凝土基体之间的界面附着力及载荷传递,从而提高了界面的极限承载力。与纯环氧树脂双剪试件相比,CFRP-混凝土界面的粘结强度和界面断裂能分别提升了129.83%和168.82%。引入纳米改性胶粘剂/CFRP-混凝土界面粘结综合影响系数α,建立了相应的CFRP-混凝土界面粘结-滑移模型,模型的计算曲线与实验曲线吻合较好。

In order to study the effect of TiO_(2)/OMMT/epoxy resin composite material on the bonding and sliding performance of CFRPconcrete interface,the ratio of TiO_(2)/OMMT/epoxy composite material was optimized and applied to the double bond shear experiment of CFRP-concrete system.The results showed that when the content of TiO_(2)+OMMT was 2wt%,the tensile strength,elongation at break and impact strength were 153.06%,159.09%and 159.19%of pure epoxy resin,respectively.When used as an adhesive in CFRP-concrete system,TiO_(2)/OMMT/epoxy composite material enhanced the interface adhesion and load transfer between fiber and concrete matrix,thus improving the ultimate bearing capacity of the interface.Compared with the double-shear specimen using pure epoxy resin,the bond strength and interface fracture energy of CFRP-concrete interface were increased by 129.83%and 168.82%,respectively.