纤维对混凝土抗渗性能及硬化水泥浆体孔结构的影响

研究了纤维掺量0.9 kg/m3时,纤维素纤维UF500、聚丙烯纤维对混凝土抗渗性能的影响。试验结果表明:这两种纤维均可以明显改善混凝土的抗渗性,改善程度均在80%以上;且纤维素纤维UF500的改善效果较聚丙烯纤维高出16%。结合压汞法对纤维掺量0～0.3%(质量百分比)的各28 d硬化水泥浆体的孔结构进行了测试与分析,探讨纤维对硬化水泥浆体孔结构的影响。结果表明:相同纤维掺量下,UF500纤维对水泥浆体孔隙率、平均孔径以及孔径分布的改善效果都明显高于聚丙烯纤维;综合孔结构参数测试结果,试验掺量范围内纤维素纤维UF500的最佳掺量为0.23%,聚丙烯纤维以0.15%最佳。

Influence of Fiber on Concrete Permeability and Pore Structure of Hard Cement Paste

Influence of cellulose fiber UF500 and polypropylene fiber on concrete permeability at the dosage of 0.9kg/m3 was investigated.Results show that both of these fibers can significantly improve concrete permeabilty at a degree more than 80%.Furthermore,improvement of UF500 fiber is 16% better than that of polypropylene fiber.Pore structures of 28d hard cement paste(HCP) with fiber dosage from 0% to 0.3%,were determined by MIP(Mercury intrusion porosimetry).Influences of fiber type and dosage on pore structures of HCP were analyzed.It shows that improving effects of UF500 on porosity,mean diameter and pore size distribution are all obviously higher than that of polypropylene fiber.In this test,the most suitable dosage of UF500 is 0.23%,while it is 0.15% for polypropylene fibers.