摘要
碳纤维增强复合材料(CFRP)已被广泛应用于混凝土结构加固工程中,但CFRP-混凝土界面常因为表层混凝土薄弱区的过早破坏而影响加固效果。鉴于此,本文采用不同浓度树脂预浸(Resin Pre-Coating, RPC)溶液对混凝土表面进行预浸处理以增强其表层力学性能。分析并阐明了体积浓度为10%~50%的RPC溶液处理混凝土表面对CFRP-混凝土界面承载力、界面应力分布及黏结-滑移关系等的影响规律及其增强机理。结果表明,RPC处理可以使环氧树脂有效渗入混凝土表层的微裂缝和孔洞,固化后的环氧树脂与混凝土之间形成机械咬合作用,能有效提高CFRP-混凝土界面力学性能,改善界面破坏形式。针对本文试验的C40混凝土,采用体积浓度为30%的RPC溶液处理,可以有效避免混凝土过早破坏,使胶层强度得到充分利用,与未经RPC处理的对照组相比,界面极限承载力提高了78.4%,界面抗剪强度和界面剪切断裂能分别提高了71.1%和3.66倍。
Although carbon fiber reinforced composites(CFRP)are widely used in strengthening of concrete structures,the strengthening effectiveness is often reduced,primarily due to premature damage in the weaker sub-surface of concrete.To address this issue,the study employed resin pre-coating(RPC)solutions with different concentrations to treat the concrete surface and improve its mechanical properties.The effects of RPC treatment with volume concentrations from 10%to 50%on the load-carrying capacity,interfacial shear stress distribution and bond-slip relationship were analyzed.Besides,the enhancing mechanisms were elucidated.The results demonstrated that the epoxy resin can efficiently penetrate into the microcracks and voids in the concrete sub-surface based on the RPC treatment.The cured epoxy resin created interlocking action between the epoxy and concrete,effectively enhancing the mechanical properties of the CFRP-concrete interface and modifying the failure mode.For the C40 concrete tested in this paper,the RPC treatment with the volume concentration of 30%effectively prevented premature concrete destruction,maximizing the adhesive layer’s strength.This resulted in a 78.4%increase in the load-carrying capacity compared to the control group with no RPC treatment.Additionally,the interfacial shear strength and interfacial shear fracture energy increased by 71.7%and 3.66 times,respectively.
作者
房恩惠
杨树桐
庞瑞阳
孙忠科
兰天
FANG Enhui;YANG Shutong;PANG Ruiyang;SUN Zhongke;LAN Tian(College of Engineering,Ocean University of China,Qingdao 266000,China)
出处
《复合材料科学与工程》
北大核心
2025年第2期117-128,共12页
Composites Science and Engineering
基金
国家自然科学基金项目(52178259)。
作者简介
第一作者:房恩惠(1999-),女,硕士研究生,主要从事CFRP片材加固混凝土结构方面的研究;通信作者:杨树桐(1979-),男,博士,教授,主要研究方向为混凝土材料与结构,shutongyang2013@163.com。
