不同纤维掺量下聚乙烯醇纤维/水泥复合材料徐变性能试验

通过对5组试件进行试验，研究了不同纤维掺量下聚乙烯醇纤维/水泥复合材料（PVA/ECC）的受压徐变性能。结果表明:PVA纤维的加入，降低了基材的密实度及弹性模量，使试件的徐变增加；在掺杂PVA纤维（体积分数为0~2vol%）的PVA/ECC试件中，PVA纤维掺量较高和掺量较低的试件徐变均较大，PVA纤维掺量适中的试件徐变较小；各组试件的徐变速率均具有前期快后期慢的特性，7天内发生的徐变可达总徐变的40%左右，60天内约为总徐变的80%，持荷约60天后，徐变逐渐趋于收敛。最后通过对试验值进行回归分析，提出了适用于PVA/ECC材料的徐变度数学计算模型及徐变系数预测模型。 

Experimental study on creep performance of polyvinyl alcohol fiber/engineered cementitious composite with different fiber contents

Based on the tests of five groups of polyvinyl alcohol fiber reinforced engineered cementitious composite(PVA/ECC)specimens,the creep performance of PVA/ECC with different fiber contents under pressure was studied in this paper.The results show that the incorporation of PVA fibers can lower density and elastic modulus of substrate materials and lead to a decline of capacity of resistance to creep.Additionally,within 0-2 vol%of volume fraction of PVA fiber,the large or small volume fraction of PVA fiber is found to increase the creep coefficient of PVA/ECC,and the medium volume of PVA fiber can decrease the creep coefficient.The creep speeds of specimens all have a character that increasing rapidly at the initial and then increasing slowly,the creep amount in initial 7 days is about 40%of total amount,that in initial 60 days is about 80%of total amount,and creep amount gradually gets convergent after 60 days.Based on the result of regression analysis to the experimental data,the calculation models of creep coefficient and creep degree of PVA/ECC were presented.