聚丙烯纤维与胶粉复掺对砂浆强度和韧性的影响

Influence of polypropylene fibers and latex powder mixing on strength and toughness of mortar

采用聚丙烯纤维与聚合物胶粉复掺的方法配制了胶粉改性砂浆，并应用正交试验和多点分布的纤维单因素试验研究了聚丙烯纤维与聚合物胶粉复掺对砂浆强度和韧性的影响。结果表明：随着纤维掺量的增加，砂浆折压比总体上呈增加趋势，长度为10 mm的聚丙烯纤维增韧效应最优；当聚丙烯纤维复合胶粉改性砂浆的折压比在0．17～0．21时，韧性显著提高；配制参数纤维掺量为0．2％、纤维长度为10 mm、胶粉掺量为5％、硅粉掺量为5％的胶粉改性砂浆的综合强度和韧性最优，适合作为混凝土剥蚀面层的修复材料。

A latex powder modified mortar was prepared by adding polypropylene fiber and latex powder,and an orthogonal ex-periment and fiber single factor experiment with multipoint distribution were conducted to investigate the influence of polypropyl-ene fibers and latex powder composite on the strength and toughness of the modified mortar.The results show that the ratio of bending-compressive strength （RBCS）tends to increase in general with the increase of fiber content.The toughness of latex pow-der modified mortar is distinctly better because its RBCS is in the range of 0.17 to 0.21.The 10 mm length polypropylene fiber is optimal to improve the bending strength and toughness of mortar.When the mixture parameters are fiber content 0 .2%,fiber length 10 mm,content of latex powder 5%and silica fume content 5%,the comprehensive strength and toughness of the latex powder modified mortar are optimal,so the modified mortar is suitable for the repair material on the concrete erosion surface.