聚丙烯纤维混凝土抗压强度与收缩性能时变规律研究

为了提高混凝土强度与改善混凝土的收缩性能,在混凝土中掺入聚丙烯纤维、硅灰及粉煤灰等掺合料,采用平行组对比试验,研究了掺合料对混凝土抗压强度和干燥收缩性能的影响规律,得到了相应的回归公式.结果表明,单掺粉煤灰的混凝土3,7,28 d抗压强度明显低于基准组,56 d抗压强度与基准组相差不大;复掺粉煤灰和硅灰混凝土的早期和后期抗压强度较单掺粉煤灰混凝土有不同程度的提高;聚丙烯纤维、粉煤灰和硅灰复掺可以显著抑制混凝土干燥收缩,且混凝土龄期与收缩率符合对数函数关系.

Time-varying regularity study on compressive strength and shrinkage of polypropylene fibers concrete

In order to improve the strength and shrinkage of concrete, a new way was proposed to make its performance better by adding admixture of polypropylene fibers, silica fume, and fly ash. By means of parallel test, the time-varying regularity of compressive strength and drying shrinkage of concrete added polypropylene fibers, silica fume and fly ash was investigated; corresponding regression formula was obtained. The results show that 3, 7, 28 days compressive strength of single fly ash concrete is significantly lower than reference group, and 56 days compressive strength and reference group have no obvious difference. Compressive strength of mixture with fly ash and silica fume of concrete than single fly ash concrete improved in different degrees on early and late, and polypropylene fibers and mineral admixtures complex admixture can significantly inhibit drying shrinkage of concrete, then concrete age and the shrinkage rate conformed to logarithmic function.