平板法研究层布式混杂纤维混凝土早期抗裂性能

试验通过平板约束试验研究粉煤灰混凝土、聚丙烯纤维混凝土、层布式钢纤维混凝土、层布式混杂纤维混凝土的早期抗裂性能,结果表明:聚丙烯纤维混凝土的最大裂缝宽度比粉煤灰混凝土减小了40%,裂缝总长度减小了25.55%,裂缝降低系数为56.56%,抗裂等级达到二级;层布式钢纤维混凝土的最大裂缝宽度比粉煤灰混凝土减小了26.7%,裂缝总长度减小了26.5%,裂缝降低系数为43.24%,抗裂等级达到三级;层布式混杂纤维混凝土的最大裂缝宽度比粉煤灰混凝土减小了67.69%,裂缝总长度减小了78.26%,裂缝降低系数为93.07%,抗裂等级达到一级。层布式混杂纤维混凝土的抗裂效果最好。

A Slab Test of Early-age Crack Resistance of Layered Hybrid Fiber Reinforced Concrete

An experimental study was carried out on early-age crack resistance of fly ash concrete, polypropylene fiber concrete, layered steel fiber reinforced concrete and layered hybrid fiber reinforced concrete by slab constrain test. The results show that compared with fly ash concrete, the max width of crack of polypropylene fiber concrete shortened by 40%, the total length decreased by 25.55%, the coefficient of crack decrease was 56.56% and the early anti-crack grade was second one; the max width of crack of layered steel fiber concrete shortened by 26.7%, the total length decreased by 26.5%, the coefficient of crack decrease was 43.24% and the early anti-crack grade was third one; the max width of crack of layered hybrid fiber concrete shortened by 67.69%, the total length decreased by 78.26%, the coefficient of crack decrease was 93.07% and the early anti-crack grade was first one. The best effect of anti-crack belongs to layered hybrid fiber reinforced concrete.