聚乙烯醇纤维混凝土早期抗裂抗渗性能试验

Effect of Polyvinyl Alcohol Fiber on Anti-cracking and Impermeability of Concrete

目的研究聚乙烯醇纤维对混凝土抗裂抗渗性能的影响.方法用3种不同长度(6 mm、8 mm、12 mm),4种不同掺量(0.6 kg/m3、0.8 kg/m3、1.2 kg/m3、1.4 kg/m3)的聚乙烯醇纤维设计13组纤维混凝土,通过平板约束试验和渗水高度试验,与基准混凝土进行对比,研究聚乙烯醇(PVA)纤维长度、掺量对混凝土早期抗裂及抗渗性能的影响.结果对比掺加不同长度纤维混凝土试件的裂缝情况及渗水深度,得出掺入8 mm的PVA纤维混凝土平均渗水深度为49.21 mm,裂缝降低系数由0.82提高到1,在聚乙烯醇纤维掺量0~1.4 kg/m3变化中不同长度的纤维均掺加1.4 kg/m3时裂缝的降低系数从0.85提高到1,平均渗水高度维持在49.76 mm,各项性能均表现最佳.结论 PVA纤维能有效抑制早期塑性裂缝的产生并显著提高材料的抗渗性,且选用长度8 mm、掺量为1.4 kg/m3的聚乙烯醇纤维时各项性能表现最佳.

In order to study the influence of polyvinyl alcohol fibers on the crack resistance and impermeability of concrete,design 13 groups of fiber concrete by using three kinds of polyvinyl alcohol fibers of different length(6 mm,8 mm,12 mm)and four different content(0.6 kg/m 3,0.8 kg/m 3,1.2 kg/m 3,1.4 kg/m 3),through the plate restraint and seepage height test,and compared with the benchmark concrete,the effect of length and content of polyvinyl alcohol(PVA)fiber on the early crack resistance and impermeability of concrete.The results show:by observing the cracks and seepage depth with different lengths of fiber concrete specimens,the average seepage height of the 8 mm PVA fiber concrete specimens is 49.21 mm,the fracture reduction factor increases from 0.82 to 1,content in the range of 0~1.4 kg/m 3,the reduction coefficient of the cracks increased from 0.85 to 1 and the average seepage height remained at 49.76 mm with 1.4 kg/m 3 of different fiber additions.PVA fibers can effectively inhibit the early plastic cracks in concrete production and it can significantly improve the impermeability of concrete.PVA fibers can effectively suppress generation of cracks in the early plastic and significantly improve the impermeability of the material,when the selection of 8 mm and the dosage of 1.4 kg/m 3 of the polyvinyl alcohol fibers best performance.