聚丙烯纤维与水泥砂浆粘结性能试验

Experimental study on bond performance between polypropylene fiber and cement mortar

提出了利用聚丙烯纤维拔出试验,分别测定水灰质量比、纤维埋入长度、纤维埋入角度和水泥砂浆龄期不同的情况下纤维拔出力-拔出位移曲线,利用扫描电镜对纤维砂浆试件断面形貌进行了分析,研究了纤维与水泥砂浆的粘结性能.研究结果表明:聚丙烯纤维-水泥砂浆具有较好的粘结性,聚丙烯纤维粘结破坏形式为拔出破坏,因此聚丙烯纤维具有较好的耗能阻裂作用;水灰质量比、纤维埋入长度、纤维埋入角度、水泥砂浆龄期直接影响着聚丙烯纤维-水泥砂浆的粘结强度,其中水灰质量比因素影响最大;当水灰质量比小于0.5时,聚丙烯纤维-水泥砂浆粘结强度和粘结功都随着水灰质量比的减小而增大,随着纤维埋入长度和纤维埋入角度的增大而增大.

The pullout test method for polypropylene fiber is presented.The force-slip curves of polypropylene fiber in different conditions are determined,including different water-cement ratio,different embedding length of fiber,different angle of the fiber and different age of cement mortar.The section shape of polypropylene fiber cement mortar is analyzed through scanning electron microscope.The results show that the bond performance between polypropylene fiber and cement mortar is well.The failure mode of polypropylene fiber is pullout fail.The polypropylene fiber with low elastic modulus has functions of energy dissipation and crack prevention.Water-cement ratio,embedding length of fiber,angle of the fiber and age of the cement mortar directly affect the bond strength between polypropylene fiber and cement mortar,in which water-cement ratio is the most influential factor.When the water-cement ratio is less than 0.5,the bond strength and bond power of polypropylene fiber with cement mortar increase with the decrease of water-cement ratio,and increases with the increase of embedding length of fiber and age of cement mortar.