纤维水泥砂浆与混凝土界面黏结性能钻芯拉拔试验研究

为研究纤维水泥砂浆与混凝土界面黏结性能,采用钻芯拉拔法试验制作模拟中型柱混凝土构件,并分别外包不同强度的聚乙烯醇纤维水泥砂浆、聚丙烯纤维水泥砂浆、钢纤维水泥砂浆。对制作的试验构件进行钻芯拉拔试验,得出界面破坏时的拉拔力,将得到的不同类型的纤维水泥砂浆构件拉拔力数据与构件混凝土轴心抗拉强度、纤维水泥砂浆抗压强度进行比较分析。结果表明,在该试验中合成纤维水泥砂浆的界面黏结强度比钢纤维水泥砂浆的界面黏结强度高;界面黏结强度与构件混凝土轴心抗拉强度呈正相关关系,与纤维水泥砂浆抗压强度呈正相关关系,界面黏结力与砂浆抗压强度呈线性相关关系。

Core drilling and pull-off tests of interfacial bond behaviors between fiber cement mortar and concrete

To investigate the interfacial bond behaviors between fiber cement mortar and concrete with core drilling and pull-off tests, medium-sized columnar concrete samples enclosed with different strengths of polyvinyl alcohol fiber cement mortar, polypropylene fiber cement mortar, and steel fiber cement mortar were prepared. Core drilling and pull-off tests were conducted on the samples to obtain the pulling force with failure occurring at the interface, and the results of different kinds of samples from pull-off tests were compared with the axial tensile strength of concrete and compressive strength of fiber cement mortar. The results show that the interfacial bond strength between synthetic fiber cement mortar and concrete is higher than that between steel fiber cement mortar and concrete, and that the interfacial bond strength is positively correlated with the axial tensile strength of concrete and compressive strength of fiber cement mortar. There is also a linear correlation between the interfacial bond strength and compressive strength of fiber cement mortar.