掺PVA纤维的水工混凝土抗冻性能研究

Research on Frost Resistance of Hydraulic Concrete Mixed with PVA Fiber

文章通过冻融循环试验,探究了三种体积掺量(1.0%、1.5%、2.0%)和两种长度规格(8mm、12mm) PVA纤维对水工混凝土抗冻性的影响规律。试验表明,水工混凝土相对动弹模量均随着冻融次数的增加整体呈递减趋势,并以未掺纤维组的降幅更显著;冻融75次时未掺PVA纤维试件已发生破坏,此时的相对动弹模量减小到56.5%,而冻融150次时掺PVA纤维试件依然未被破坏,相对动弹模量仍> 85%,研究成果可以为解决东北地区水工结构冻融破坏问题提供一定参考。

In this paper,the effects of three kinds of PVA fibers(1.0%,1.5%,2.0%)and two kinds of length specifications(8mm,12mm)on the frost resistance of hydraulic concrete were investigated through freeze-thaw cycle tests.The test results show that the relative dynamic modulus of hydraulic concrete decreases with the increase of freeze-thaw times,and the decrease is more significant in the unmixed fiber group;at 75 freeze-thaw times,the sample without PVA fiber was damaged,and the relative dynamic modulus decreased to 56.5%,while at 150 freeze-thaw times,the sample with PVA fiber was still not damaged,and the relative dynamic modulus was still greater than 85%.The research results can provide a certain reference for solving the freeze-thaw failure problem of hydraulic structures in Northeast China.