关键词: 钢纤维, 聚乙烯醇纤维, 混合纤维增强水泥基复合材料, 应变率, 冲击实验, 动力性能

Abstract: The impact compression tests of hybrid fiber ( steel and polyvinyl alcohol ( PVA) fiber) -reinforced cement- based composites ( HFRCC) of different ratios were conducted at different strain rates by using a split Hopkinson pressure bar ( SHPB) . Then, their dynamic compressive strength, peak strain and tenacity are compared. The results show that (1) HFRCC is sensitive to strain rates; (2) the peak strain increases with the PVA fiber content and the addition of steel fiber can increase the dynamic compressive strength; (3) to increase the PVA fiber content can decrease the dynamic strength increase factor; and (4) at a low strain rate and before the stress reaches up to a peak, the relative contents of two kinds of fibers have little influence on the tenacity of HFRCC. At a high strain rate, however, the steel fiber can effectively improve the tenacity of HFRCC.

Key words: steel fiber, polyvinyl alcohol fiber, hybrid fiber-reinforced cement-based composites, strain rate, impact test, dynamic mechanical property