纤维种类对混凝土的抗冻性能的影响

Influence of fiber types on frost resistance of concrete

为研究聚乙烯纤维和聚丙烯纤维对混凝土的抗冻性能的影响,分别制备了聚乙烯纤维混凝土、聚丙烯纤维混凝土和聚乙烯-聚丙烯纤维混凝土试件,对其进行了0、50、100次的冻融循环试验。并以混凝土的弹性模量和抗压强度作为指标对性能变化进行评价。在冻融循环100次后对分别静置0、7、14 d后的聚乙烯-聚丙烯纤维混凝土试块再次进行性能测试。通过试验得出:(1)双掺纤维混凝土的弹性模量和抗压强度要好于单掺纤维混凝土。(2)在单掺纤维混凝土中,聚丙烯纤维对混凝土性能的提升要好于聚乙烯纤维。(3)冻融循环次数和静置时间对混凝土的弹性模量和抗压强度有着很大的影响。冻融循环次数的增加会显著降低纤维混凝土的两种性能,静置时间在0-7 d内会显著降低纤维混凝土的两种性能。

In order to study the influence of polyethylene fiber and polypropylene fiber on the frost resistance of concrete,the specimens of polyethylene fiber concrete,polypropylene fiber concrete and polyethylene polypropylene fiber concrete were prepared respectively,and the freeze-thaw cycle tests were carried out for 0,50 and 100 times.The modulus of elasticity and compressive strength of concrete are taken as indexes to evaluate the performance change.After 100 cycles of freeze-thaw,the properties of PE-polypropylene fiber concrete specimens after 0,7 and 14 days were tested again.The results show that(1)the modulus of elasticity and compressive strength of double fiber reinforced concrete are better than that of single fiber reinforced concrete.(2)In single fiber concrete,polypropylene fiber is better than polyethylene fiber in improving the performance of concrete.(3)The number of freeze-thaw cycles and standing time have a great influence on the modulus of elasticity and compressive strength of concrete.The increase of freeze-thaw cycles will significantly reduce the two properties of fiber reinforced concrete,and the static time in 0-7 days will significantly reduce the two properties of fiber reinforced concrete.