钢管混凝土界面法向粘结强度试验研究

为研究钢管混凝土界面之间的脱粘问题,采用了对拉法和弯拉法进行了钢与混凝土法向粘结力测试,通过对试验方法和结果的分析得到了界面粘结强度值,在此基础上,进行了温度变化和核心混凝土收缩作用下的钢管混凝土截面的脱粘分析。分析表明,弯拉法是一种较好的钢与混凝土法向粘结力测试方法;混凝土强度对粘结强度没有明显的影响,钢板的表面状况对粘结强度有一定的影响,表面锈蚀的粘结强度大于表面光滑的;通过对弯拉法试验结果的分析得到钢与混凝土的法向粘结强度为0.86 MPa;在温度变化、收缩等作用下,钢管混凝土拱肋界面极易发生脱粘。首次进行了钢与混凝土法向粘结强度试验,试验的方法和结果可以为钢管混凝土拱脱粘问题的研究提供参考,促进钢管混凝土拱桥的工程应用。

An experimental study on interfacial bond strength of concrete filled steel tube

In order to study the debonding of concrete filled steel tubes(CFST),pulling and bending methods were used to test the interfacial bond strength.Based on the test results,the debonding due to temperature change and shrinkage of core concrete in CFST was analyzed.The test and analysis results show that the bending method is a better way for bond strength test;that the concrete strength has little influence on bond strength while the surface condition of the steel has much influence on it,and the bond strength of the steel which is rust is greater than that of the steel with smooth surface.According to the bending test results,an interfacial bond strength of 0.86 MPa was obtained.Debonding will easily happen in CFST when temperature changes or core concrete shrinks.The bond strength test was firstly carried out,and the test methods and results can provide a reference for the research on the debonding of CFST arch,which will play a catalytic role in CFST arch bridge engineering applications.