混杂纤维增强延性水泥基复合材料力学性能与裂宽控制

摘要

In order to obtain a new type of engineered cementitious composites of high strength and high strain capacity,the tensile and compressive behaviors of hybrid polyvinyl alcohol-steel fiber reinforced cementitious composites have been evaluated on incorporating additional steel fiber.The experimental results show that cracking and tensile strength of the composites are increased with the addition of steel fiber.Meanwhile,the individual crack width is decreased compared with the case without steel fiber.The above enhancement of additional steel fiber is more pronounced in high strength matrix.Moderate amount of steel fiber is needed to effectively improve the ultimate tensile strain of the composites.However,no significant improvement on compressive behavior of the composites has been achieved by incorporating steel fiber.Hybrid fiber reinforced composites with characteristics of high strength,high ductility and fine crack width are obtained.%为实现纤维增强延性水泥基复合材料高强度与高延性的匹配,在原有材料体系中附加钢纤维,试验研究了混杂聚乙烯醇(PVA)/钢纤维增强延性水泥基复合材料的轴拉、抗压性能.结果表明:随着钢纤维掺量的增加,混杂纤维增强延性水泥基复合材料开裂强度和抗拉强度不断提高,裂纹宽度显著降低,且钢纤维对高强基材的作用效果更加显著;当钢纤维掺量适量时,混杂纤维增强延性水泥基复合材料的极限拉应变得到有效提升,而钢纤维掺量对抗压性能的影响并不显著;PVA纤维和钢纤维混杂可获得高强度、高延性和低裂纹宽度的水泥基复合材料.