钢管混凝土界面粘结强度试验分析-结构工程专业论文.docxVIP

Abstract Abstract II II EXPERIMENTAL RESEARCH ON BOND STRENGTH OF CONCRETE FILLED STEEL TUBE COLUMNS ABSTRACT In recent years, the CFST as a combination of material is more and more widely used in engineering with its good mechanical performance and economic rationality. Its good mechanical performance is based on the bond strength between the steel and concrete. Some research work has been carried out on the bond carrying capacity of CFST. In order to ensure that these two materials can work together, interfacial adhesion of steel and concrete is highlighted. The mainly factors impacted on the interface bonding are steel and core concrete. The interface between steel and concrete will have the inevitable initial imperfections, when under external loads, these initial defects continue to accumulate and develop, resulting in interface bonding performance degradation, bond stress reduction, structural capacity decline. Therefore, we must explore the initial damage of the impact on material properties, identify ways to reduce and prevent the occurrence and the development of the initial defects. The research work is summarized as follows: The width-thickness ratio and water-cement ratio are considered as the two basic parameters, The push-out test is designed nine CFST columns presented by using the orthogonal experimental method. the role of interfacial adhesion were been discussed, Obtain the law of interface bonding strength changes with the width to thickness ratio and water-cement ratio. The statistic regression analysis has reflected the deformation rule of the bond strength. To explore the mechanical properties affected by the pipe polished and ribbed, the test that 11 specimens designed with the parameters was carried out, examining CFST interface bond performance. Put fly ash、expansion agent and polyacrylonitrile fiber into the concrete. To probe the mechanical properties affected by the change of concrete character, the test that 4 specimens designed with the