PVA纤维对混凝土干缩及抗侵蚀性能的影响研究

Study on the Effect of Erosion Resistance of Mortar with PVA Fiber in the Different Alkali Concentration

将长度12 mm、直径31μm的PVA纤维以不同体积掺量掺入到混凝土中,分别测试其6个养护龄期的干缩率,同时制备标准试件,在标养28 d后,将其置于浓度为30000 mg/L的硫酸钠溶液中,达到设定侵蚀龄期后,测定各组试件的抗压强度、劈裂抗拉强度,并以抗压抗蚀系数评价碱环境下PVA纤维对混凝土抗侵蚀性能的影响。研究结果表明:适量掺入PVA纤维对混凝土的干缩性能有明显提升;而在碱侵蚀环境作用下,各组试件的力学性能有不同程度的下降,相比于基准组,PVA纤维能有效提升混凝土的力学性能和抗蚀系数,且PVA纤维体积掺量为0.2%时效果最好。

In this paper,PVA fibers of 12 mm in length and 31μm in diameter were mixed into concrete with different volume dosage to test the dry shrinkage rate of 6 curing ages respectively.At the same time,standard specimens were prepared.After standard cultivation for 28 d,they were placed in sodium sulfate solution with a concentration of 30000 mg/L.The compressive strength and splitting tensile strength of each sample were measured,and the influence of PVA fiber on the corrosion resistance of concrete in alkali environment was evaluated by the compressive and corrosion resistance coefficient.Results show that a proper amount on the drying shrinkage of concrete mixed with PVA fiber performance has improved significantly,and under the effect of alkali corrosion environment,the groups of mechanical properties of the specimens with different degree of decline,compared to the baseline group,PVA fiber can effectively improve the mechanical properties and corrosion resistance coefficient of concrete,and PVA fiber volume content of 0.2%when the effect is best.