西北大温差地区钢管混凝土构件温度场及脱粘分析

为研究西北大温差条件下钢管混凝土构件截面温度场变化规律及钢管与核心混凝土界面脱粘情况，选取新疆乌鲁木齐市和青海西宁市典型日平均大气温度，通过温度冲击循环环境模拟试验方法分为12个时间段在大气模拟箱分别进行素混凝土、钢管混凝土构件温度场和钢管混凝土构件脱粘测试试验，分析西北大温差环境钢管混凝土温度场变化和界面结合状态。结果表明：钢管混凝土构件在大温差反复作用下，因材料差异产生的不同步热胀会使钢管与核心混凝土发生界面脱粘现象，温差越大越明显；同一个系列上径向温度变化中，随直径缩小，温度变化越滞后；当大气温度骤降时，钢管对核心混凝土会产生套箍作用，且温度越低，钢管的套箍作用越强。

Analysis of Temperature Field and Debonding of CFST Members in Northwest Region of Large Temperature Difference

In order to study the variation law of temperature field in the cross-section of steel tube concrete components and the debonding situation of the interface between steel tube and core concrete under the conditions of large temperature difference in the northwest, typical daily average atmospheric temperatures in Urumqi, Xinjiang and Xining, Qinghai were selected. Through temperature impact cyclic environmental simulation testing methods, the temperature field of plain concrete, steel tube concrete components, and debonding testing of steel tube concrete components were conducted in twelve time periods in atmospheric simulation boxes, the interface bonding state of steel tube concrete in the temperature field of sudden temperature changes under the large temperature difference environment in the northwest is analyzed.The results show that, under the repeated action of large temperature difference, the non-synchronous thermal expansion caused by material difference will cause interface debonding between steel tube and core concrete, and the greater the temperature difference is, the more obvious it is. When the radial temperature changes on the same series, the temperature changes lag more with the diameter decreasing. When the atmospheric temperature drops sharply, the steel pipe will have a coupling effect on the core concrete, and the lower the temperature, the stronger the coupling effect of the steel pipe.