FRP约束橡胶混凝土柱的力学性能与破坏机理研究

With the rapid development of the automobile industry, the number of discarded tires has increased dramatically. How to effectively utilize waste tries to reduce their negative effects on environments is an urgent issue to be solved. Fiber reinforced polymer (FRP) confined crumb rubber concrete (CRC) not only improves the mechanical properties of crumb rubber concrete, but also recycling used tires, which has a great beneficial effect on environment. However, there are few studies focusing on the mechanical properties of FRP confined CRC. In this study, static and dynamic mechanical properties of FRP confined CRC columns with different cross-sections will be studied by using the method of experimental test, theoretical analysis and numerical simulation. Firstly, based on the FRP tensile test and the CRC axial compression test, the effect of strain rates on the mechanical properties of FRP and CRC materials will be determined. Secondly, based on the methods of monotonous and cyclic loading experimental tests and the finite element analysis, the influence of loading rate on the mechanical properties of FRP confined CRC column can be obtained. The unified stress-strain model of FRP confined CRC column under dynamic and static loading will be developed. Finally, combined numerical analysis and experimental verification, the dynamic and static mechanical properties of FRP confined CRC piers with different cross sections under low cyclic reversed loading will be investigated. The design method of FRP confined CRC piers under different loading rates will be proposed.

随着汽车工业的迅猛发展，废旧轮胎的数量急剧增加。如何有效地回收利用废旧轮胎，减少其对环境的污染，是一个亟需解决的课题。纤维增强聚合物(FRP)约束橡胶混凝土(CRC)既能改善CRC的力学性能，又能回收利用废旧轮胎，极具环保意义。目前FRP约束CRC力学性能的研究处于初始阶段。本项目拟采用试验测试、理论分析和数值模拟相结合的方法，分析FRP约束不同截面CRC柱的动静态力学性能和破坏机理。首先，通过FRP拉伸试验和CRC轴压试验，确定FRP和CRC动静态力学特性；其次，基于FRP约束CRC柱的轴向单调、轴向反复加载试验和有限元分析，明确加载速率对FRP约束不同截面CRC柱力学性能的影响，提出FRP约束不同截面CRC柱的动静态应力-应变关系统一模型；最后，结合数值分析与试验验证，探明低周反复荷载下FRP约束不同截面CRC墩柱的动静态力学性能，从而提出不同加载速率下FRP约束CRC墩柱设计方法。

为了充分利用再生资源、减少环境污染，采用废旧橡胶轮胎颗粒制备橡胶混凝土（CRC）是一种发展趋势。CRC具有良好的韧性、抗冲击性、抗震性，但是其弹性模量和抗压强度相对较低，为改善CRC的缺点，并在建筑结构中推广应用FRP约束CRC柱，本项目采用试验测试、理论分析和数值模拟相结合的方法，分析了FRP约束不同截面CRC柱的破坏状态和动静态力学性能。首先，通过FRP拉伸试验和CRC轴压试验，确定了FRP和CRC动静态力学特性；其次，基于FRP约束CRC柱的轴向单调、轴向反复加载试验和有限元分析，明确了加载速率对FRP约束不同截面CRC柱力学性能的影响，提出了FRP约束不同截面CRC柱的动静态应力-应变关系模型；最后，结合数值分析与试验数据，探明了低周反复荷载下FRP约束不同截面CRC墩柱的抗震性能，并对不同橡胶含量的FRP约束CRC墩柱的抗震性能进行了评估。本项目的研究表明，FRP与CRC有效的结合起来，充分发挥了FRP的约束作用和橡胶混凝土的优点，具有突出的力学性能与抗震性能。本项目获得一批原创性的成果，为FRP约束CRC的工程应用提供了试验基础与理论依据。