基于树脂预浸技术的短切Kevlar纤维增强CFRP-混凝土界面力学性能研究

doi:10.19936/j.cnki.2096-8000.20220528.007

摘要/Abstract

摘要： 为了提高CFRP(碳纤维增强复合材料)与混凝土界面的黏结性能,本文利用树脂预浸技术(RPC)对混凝土表面进行浸润处理,并采用短切Kevlar纤维对树脂层进行增强。随后,基于单剪试验,分析CFRP与混凝土界面黏结性能。首先在黏结长度不变的条件下明确采用RPC技术的加固效果,通过对不同纤维掺量条件下界面极限黏结承载力分析,探究纤维的最佳掺量;其次,基于最佳掺量,分析不同黏结长度对不同处理方式界面黏结性能的影响。结果表明:纤维最佳掺量为9 g/m²。且不同黏结长度条件下,经RPC技术处理的界面极限黏结承载力相比未经处理的提高12.7%~142.9%。此外,增强界面的破坏形式主要表现为胶层剪切破坏并伴随少量混凝土的剥离。RPC技术可以对混凝土表层微裂缝进行填充,从而改变了传统加固方式中混凝土层剥离深度较大的破坏形式;散乱分布纤维的桥联作用,使得树脂层得到增强,抑制了裂纹的发展,从而提高了界面的黏结强度。

关键词: Kevlar纤维, CFRP, 树脂预浸技术, 界面增强

Abstract: In order to improve the bonding performance between CFRP (Carbon fiber reinforced polymer) and concrete, resin pre-coating technique (RPC) was used to pretreat the concrete surface, and short chopped Kevlar fibers were used to reinforce the resin layer. The interfacial bond behavior between CFRP and concrete was then analyzed by the single-lap shear test. Firstly, the effect of RPC technique was evaluated for the specimens with the same bond length. The optimal fiber content was determined upon the comparisons between the maximum bond loads with different fiber contents. Secondly, based on the optimal fiber content, the effects of different bond lengths on the bond properties with different interfacial treatments were analyzed. The results show that the optimal fiber content is 9 g/m². For the specimens with different bond lengths, the maximum bond load with RPC technique is increased by 12.7%~142.9% compared to the specimens without any interfacial treatment. Moreover, the failure mode of the reinforced interface is mainly the shear failure of the adhesive layer accompanied by few peeled concrete layers. RPC technique can fill the micro cracks in the concrete surface, and then the failure mode of peeled concrete layer with deep depth can be avoided. The bridging effect provided by the random distributed fibers strengthens the resin layer, and inhibits the development of cracks. Thus, the bond strength is improved significantly.

Key words: Kevlar fiber, CFRP, resin pre-coating, interfacial reinforcement

中图分类号:

TB332

刘畅, 杨树桐, 杨松, 冯耀东, 徐铭崎. 基于树脂预浸技术的短切Kevlar纤维增强CFRP-混凝土界面力学性能研究[J]. 复合材料科学与工程, 2022, 0(5): 52-60.

LIU Chang, YANG Shu-tong, YANG Song, FENG Yao-dong, XU Ming-qi. Study on mechanical properties of CFRP-concrete interface reinforced by short chopped Kevlar fiber based on resin pre-coating technique[J]. COMPOSITES SCIENCE AND ENGINEERING, 2022, 0(5): 52-60.

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