PVA纤维对水工抗冲磨混凝土性能的影响

Influence of polyvinyl alcohol fiber on properties of hydraulic abrasion-resistant concrete

为了改善混凝土的抗裂性能和抗冲磨性能,确保泄水建筑物的安全运行,在抗冲磨混凝土中掺入具有高强度和高弹性模量的聚乙烯醇(PVA)纤维.研究了PVA纤维混凝土的力学性能、变形性能、抗裂性能和抗冲磨性能,并与聚丙烯(PP)纤维混凝土的性能进行了对比.试验结果表明:当PVA纤维掺量为0.9kg/m3时,混凝土的28,90和180d抗压强度基本不变;劈拉强度分别增加了4.4%,8.4%和5.7%;极限拉伸值分别增加了10%,11%和4%.PVA纤维对混凝土早期干缩有一定的抑制效果,但后期混凝土的干缩值略有增加;混凝土塑性阶段的抗裂性能提高;混凝土的90和180d抗冲磨强度增加.与PP纤维相比,PVA纤维对抗冲磨混凝土性能的改善效果更好.

In order to improve the crack-resistant properties and abrasion-resistant properties of concrete and thus ensure the safe operation of discharge structures,the polyvinyl alcohol（PVA） fiber with high strength and elastic modulus is added to the abrasion-resistant concrete.The mechanical properties,deformation properties,crack-resistant properties and abrasion-resistant properties of the PVA fiber reinforced concrete are studied,and also compared with those of the polypropylene（PP） fiber reinforced concrete.The results show that the PVA fiber reinforced concrete with a content of 0.9 kg/m3 fiber has no significant change in compressive strength,while its 28,90 and 180 d splitting tensile strengths are increased by 4.4%,8.4% and 5.7%,respectively,and the ultimate tension values of 28,90 and 180 d are increased by 10%,11% and 4%,respectively.The PVA fiber has beneficial effect on the early-age drying shrinkage of concrete,but somewhat adverse effect on the late-age drying shrinking.The PVA fiber reinforced concrete has favorable anti-cracking properties at the plastic stage and the abrasion-resistant strengths of 90 and 180d are increased.Compared with the PP fiber,the PVA fiber is better in improving the performance of the abrasion-resistant concrete.