高温后半灌浆套筒抗拉性能试验研究

对灌浆料标准试块和铸铁半灌浆套筒连接件进行了常温、200℃、300℃、400℃、600℃的抗压强度试验和单向拉伸试验。研究了温度对灌浆料性能的影响，以及锚固长度、保护层厚度对高温后半灌浆套筒钢筋连接试件抗拉性能的影响，分析了高温后半灌浆套筒连接破坏模式的转变。结果表明：灌浆料抗压强度随温度的升高而降低，在经历600℃高温后，灌浆料抗压强度损失达73%；套筒试件经历高温后由钢筋屈服后断裂破坏逐渐变为钢筋屈服拔出破坏，最终变为钢筋屈服前拔出破坏；无保护层试件抗拉性能在各个温度下均低于有保护层试件。基于试验数据给出了灌浆料抗压强度随温度变化的计算公式及半灌浆套筒极限拉力随温度和锚固长度变化的计算公式，为相关设计及工程施工提供参考。

EXPERIMENTAL STUDY ON TENSILE PROPERTIES OF SEMI-GROUTING SLEEVE AFTER HIGH TEMPERATURE

The compressive strength test and uniaxial tensile test of standard test block of grouting material and cast iron semi-grouting sleeve connector were carried out at room temperature, 200 ℃, 300 ℃, 400 ℃ and 600 ℃, respectively. The influence of temperature on the performance of grouting material, and the influence of anchoring length and protective layer thickness on the tensile properties of semi-grouting sleeve connection specimen after high temperature were studied, and the change of failure mode of semi-grouting sleeve connection after high temperature was analyzed. The results showed that the compressive strength of grouting material decreased with the increase of temperature, and that the loss of compressive strength of grouting material was 73% after 600 ℃ temperature. After high temperature, the fracture failure of sleeve specimen gradually changed from steel-bar yield failure to steel bar yield pull-out failure, and finally became pull-out failure of steel bar before yielding, and the tensile performance of unprotected specimens were lower than that of protected specimens at all cases of temperature. Based on the test data, the calculation formula is respectively developedfor the compressive strength of grouting material varying with temperature and for the ultimate tensile force of semi-grouting sleeve varying with temperature and with anchoring length, which provided a reference for related design and engineering construction.