海洋环境下FRP型材-混凝土组合界面受力性能及其劣化机理

This project aims to study the deterioration of the mechanical properties and the mechanism of the FRP profile-concrete composite interfaces (referred to as the composite interfaces) under the marine environment. Firstly, the double-lap tensile shear tests of the composite interfaces will be carried out to study the bonding properties of the interface under the marine environments such as hygrothermal environment, seawater immersion environment, analysis will be done to prove its failure modes and to analysis the failure mechanisms, based on which the degradation law and the deterioration mechanism of the interfacial bonding properties of the composite interfaces will be revealed, thus the interfacial bond slip model and bearing capacity model under the influence of the marine environments will be established. Secondly, the double-lap tensile shear tests of the composite interfaces will be carried out to study the bonding properties of the interface under the hygrothermal environments and seawater immersion environments coupled with the pre-applied dead load, analysis will be done to reveal the degradation law and the deterioration mechanism of the interfacial bonding properties of the composite interfaces, thus the interfacial bond slip model and bearing capacity model under the coupling influence of the marine environments and the pre-applied dead load will be established. Finally，the double-lap tensile shear tests of the composite interfaces will be carried out to study the interfacial bonding properties of the composite interfaces under the marine environments (such as hygrothermal environments and seawater immersion environments) coupled with the fatigue loading, analysis will be done to reveal the degradation law and the deterioration mechanism of the interfacial bonding properties of the composite interfaces, thus degradation model and the durability prediction model of the composite interfaces under the coupling influence of the marine environments and the fatigue loading will be established. And the research results will provide a theoretical basis for the design of FRP profile-concrete composite structures.

本项目系统研究海洋环境下FRP型材-混凝土组合界面（以下简称组合界面）的受力性能及其劣化机理。首先通过开展组合界面在湿热、海水浸泡等海洋环境因素影响下粘结性能的拉伸双面剪切试验研究，分析其破坏模式和失效机理，揭示界面粘结性能的退化规律及其劣化机理，建立考虑海洋环境因素影响的界面粘结滑移本构模型和承载力计算模型。其次，通过组合界面在湿热、海水浸泡等环境因素与恒荷载共同作用下粘结性能的拉伸双面剪切试验研究，分析界面粘结性能随恒荷载和侵蚀龄期等因素的变化规律，建立考虑环境因素和恒载共同作用影响的界面粘结滑移本构模型和承载力计算模型。最后，通过开展组合界面在湿热、海水浸泡等海洋环境因素与疲劳荷载共同作用下粘结性能的试验研究，分析界面粘结性能的退化规律和劣化机理，建立考虑海洋环境因素与疲劳荷载耦合作用影响的界面粘结性能退化模型和耐久性预测模型。研究成果有望为组合界面的设计提供数据支撑和理论依据。

组合界面是FRP型材-混凝土组合结构的薄弱和关键部位；确保组合界面的可靠和耐久是发展FRP型材-混凝土组合结构的前提和基础。本项目研究海洋环境下FRP型材-混凝土组合界面的受力性能极其劣化机理。系统研究了各类组合界面（湿粘结、干粘结、剪力键、剪力键-湿粘结界面）在恒温海水浸泡下的界面粘结性能、恒荷载与恒温海水耦合作用下各类组合界面（湿粘结、干粘结、剪力键、剪力键-湿粘结界面）的界面粘结性能、各类组合界面在循环载作用下的疲劳力学性能，以及各类组合界面在环境与荷载耦合作用下的疲劳性能。开展了组合界面粘结性能的数值模拟，分析了界面粘结强度随着环境作用龄期而衰减的机理和衰减的速率，从而为新型组合界面的耐久性设计提供数据支撑。