地铁车站抗裂防渗混杂纤维混凝土试验研究

Experimental Study on Crack and Seepage Resistant Hybrid Fiber Concrete in Subway Station

摘要:

以玄武岩纤维掺量（体积分数分别为0.05%、0.10%、0.15%）、聚丙烯纤维（体积分数分别为0.05%、0.10%、0.15%）、粉煤灰掺量（质量分数分别为15%、20%、25%）为主要影响因素进行混杂纤维混凝土正交试验；然后通过平板约束试验和渗水高度法试验，测定混杂纤维混凝土平均开裂面积和平均渗水高度，分析以上3种材料对混凝土早期抗裂和抗渗性能的影响。测试结果表明：与基准混凝土比较，聚丙烯纤维对混杂纤维混凝土抗裂性能影响最大，其体积分数为0.15%时混凝土的总开裂面积最小，其次是玄武岩纤维；对抗渗性能而言，玄武岩纤维的影响最为显著，其体积分数为0.10%时混凝土的平均渗水高度最小，其次是聚丙烯纤维；粉煤灰的影响均最小。当玄武岩纤维、聚丙烯纤维的体积分数均为0.10%、粉煤灰质量分数为20%时，混杂纤维对混凝土抗裂、防渗性能最为有利。

Abstract:

The basalt fiber (content 0.05%, 0.10% and 0.15%), polypropylene fiber (content 0.05%, 0.10% and 0.15%), fly ash (content 15%, 20% and 25%) are selected as the main influencing factors to carry out the orthogonal test of hybrid fiber concrete. And then through the plate constraint test and seepage height test, the average cracking area and average seepage height of hybrid fiber concrete are measured, which analyze the influences of the above three materials on the early cracking and seepage resistances of the concrete. The test results show that compared with the reference concrete, the polypropylene fiber has the greatest effect on the cracking resistance of hybrid fiber concrete, and the total cracking area is the smallest when its volume content is 0.15%, followed by the basalt fiber. In terms of seepage resistance, the basalt fiber has the most significant effect, and the mean seepage height is the lowest when its volume content is 0.10%, followed by polypropylene fiber. The effect of fly ash content is minimal. When the contents of basalt fiber and polypropylene fiber are all 0.10% and the content of fly ash is 20%, the hybrid fiber is the most favorable to crack resistance and seepage resistance of concrete.