PVA纤维掺量对水工混凝土抗裂性能的影响

为考察聚乙烯醇(PVA)纤维掺量对水工混凝土抗裂性能的影响,测试了0(基准)、0.1%、0.2%和0.3%等PVA纤维掺量下混凝土的力学、变形和早期抗裂性能。结果表明:0.1%掺量时混凝土坍落度由175 mm下降到80 mm,下降幅度超过了50%;PVA纤维混凝土抗压强度、轴向抗拉强度和抗拉弹性模量略有降低,极限拉伸值变化不明显,与基准组相比,0.1%、0.2%和0.3%掺量时混凝土单位面积上的总开裂面积分别降低了38%、60%和45%;0.1%掺量时干缩率最低,0.2%和0.3%掺量时略有增加。基于上述结果,建议PVA纤维体积掺量为0.1%。

Influence of PVA fiber proportion on anti cracking performance of hydraulic concrete

For investigating the influence from Polyvinyl Alcohol （PVA） fiber proportion on the anti cracking performance of hydraulic concrete，the mechanical，deformation and early age anti cracking performances of the concrete under the PVA fiber proportion of 0 （basic），0.1%，0.2% and 0.3% are tested. The result shows that when the proportion is 0.1%，the concrete slump is lowered from 175 mm to 80 mm with the lowering amplitude over 50%. The compressive strength，axial tensile strength and elastic tensile modulus of the PVA fiber reinforced concrete are lowered a little bit，but the ultimate tensile value is not obviously changed. Compared with the basic group，the total cracking areas within the unit area of the concrete with the proportion of 0.1%，0.2%，0.3% are lowered by 38%、60% and 45%，while the dry shrinkage rate is the lowest，when the admixture is 0.1% and are increased a little bit，when the admixtures are 0.2% and 0.3%. On the basis of the result mentioned above，the PVC fiber admixture of 0.1% is suggested herein.