高温下植筋黏结—滑移性能试验研究

Experimental Study on BondSlip Behavior of Postinstalled Rebar at High Temperature

摘要:

为了研究高温下植筋的黏结—滑移性能,进行了高温下3 d植筋试件的拉拔试验.试验采用电炉加热升温,温度范围为25~350 ℃.当植筋试件加热到达设定温度后,立即进行拉拔试验,每个温度下进行5组试验.试验中量测了植筋试件的温度、拉拔力和滑移.根据试验结果拟合出了极限黏结力,峰值滑移随温度变化的公式.建立了高温下植筋黏结—滑移模型和高温下植筋本构关系模型.试验结果表明,当温度高于350 ℃后,植筋胶黏结力约为常温下4%,基本丧失承载力.

Abstract:

Specimens with 3d embedment depth were tested under different temperatures to study the bondslip behavior of postinstalled rebar.The specimens were heated by the electric furnace,and the test temperature ranged from 25 ℃ to 350 ℃.Records had been made on specimen temperatures,rebar slips and loads.When the specimen temperature reached to the design temperature,the specimen was tested and 5 specimens were tested at each design temperature.Based on the test results,the fitting model about ultimate strength and temperature and the fitting model about peak slip and temperature were obtained.While the fitting model about bond stress,temperature and slip was achieved,anchorage adhesive constitutive relationship at high temperature was obtained.The test results show that the ultimate strength decreases with the temperature increase,especially the ultimate strength is 4% of that of ambient temperature when the temperature is above 350 ℃.