钢管混凝土界面经历升、降温火灾后的粘结性能研究

项目名称： 钢管混凝土界面经历升、降温火灾后的粘结性能研究

项目编号： No.51308539

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 谭清华

作者单位： 中国人民解放军国防科学技术大学

项目金额： 28万元

中文摘要： 钢管混凝土充分发挥了混凝土和钢材的优点，在工程结构中得到了广泛应用。钢管与混凝土之间的粘结作用是两者能共同工作的基础。目前，已有不少关于其常温下界面粘结性能的研究，相比火灾后粘结性能的研究比较少。因此，开展该方面的研究具有重要的理论应用和应该价值。 本项目采用试验研究和理论分析相结合的方法，深入研究火灾后钢管混凝土界面的粘结性能。首先开展钢管混凝土试件的升、降温火灾试验和相应火灾后推出试验，分析界面粘结力的传递规律及各参数对粘结强度的影响规律，得出火灾后粘结强度公式和粘结力-相对滑移本构关系；接着建立考虑材料劣化以及钢管与混凝土相互作用的钢管混凝土火灾后推出滑移的精细有限元模型，采用试验进行验证；基于建立的有限元模型，深入探讨钢管混凝土的粘结滑移机理；在此基础上，进行考虑界面粘结滑移的钢管混凝土结构（构件和节点）火灾后承载力的参数分析，得到各参数的影响规律，并提出相应的计算方法和设计建议。

中文关键词： 钢管混凝土；火灾后；界面；粘结强度；试验研究

英文摘要： Concrete filled steel tubular (CFST) structure combines the advantages of both steel and concrete, which is increasingly used in engineering structures. The bond behavior of the interface between concrete and steel is fundamental to achieve composite action for CFST structure. In the past, many studies have been performed on the bond behavior between steel and concrete for CFST columns at ambient temperatures. However, there are few research on the bond behavior of CFST members after fire. Therefore, it is of theoretical and applied significance to study the bond behavior of the CFST interface after exposure to fire. In this study, the postfire bond behavior of the CFST interface is investigated thoroughly by experimentation and theoretical analysis. Firstly, CFST columns subjected to fire including heating and cooling and corresponding push-out tests are conducted successively. The bond stress transfer between the steel and concrete and the effects of different parameters on bond strength are analysed and formulae for bond strength and bond stress to relative slip model are proposed. A refined finite element analysis (FEA) model for bond-slip behavior of CFST column after fire including the degradation of materials and the interaction between the steel and concrete is established and verified by the above tests

英文关键词： concrete filled steel tube （ CFST）；post-fire；interface；bond strength；experimental investigation