钢纤维-玄武岩纤维混杂对再生混凝土抗冻性能的影响

Influence of steel fiber and basalt fiber on the frost resistance of recycled concrete

为了使得再生混凝土满足寒冷地区抗冻性能的应用要求,研究了钢纤维与玄武岩纤维混杂情况下对再生混凝土抗冻性能的影响,通过快速冻融试验,对相对动弹性模量、质量损失率以及抗压强度等相关抗冻性能指标进行了测试。研究表明:钢纤维和玄武岩纤维无论单掺或者混杂掺入,再生混凝土的抗冻性能较未掺纤维的普通再生混凝土均有不同程度的提高,且2种纤维混杂后对再生混凝土的抗冻性能提高效果更明显,钢纤维与玄武岩纤维的最优体积掺量分别为2%、0.2%。其原因可能为:纤维的掺入改变了混凝土基体的内部孔结构,增加了再生混凝土密实性,进而提高再生混凝土的抗冻性能。

In order to make recycled concrete meet the application requirements of frost resistance in cold regions,this paper mainly studies the influence of steel fiber and basalt fiber on the frost resistance of recycled concrete.Based on the rapid freeze-thaw test of hybrid fiber recycled concrete,the relative dynamic modulus of elasticity,mass loss rate and compressive strength were measured.The results show that:single fiber has a positive effect on the frost resistance of recycled concrete,and the improvement rate of the frost resistance of recycled concrete is more obvious after mixing;the optimal volume content of two kinds of fiber is 0.2%for basalt and 2%for steel fiber respectively.The reason may be that the fiber changes the internal pore structure of concrete matrix,increases the compactness of recycled concrete,and then improves the frost resistance of recycled concrete.