【摘要】 本文讨论了聚丙烯纤维与３ 种尺寸的钢纤维混杂增强水泥基复合材料，总纤维体积率在０－４％ ～０－９５ ％ 范围内．采用带预制裂纹的、尺寸为１００ ｍｍ ×１００ ｍｍ ×５００ ｍｍ 的棱柱体四点弯曲试验，研究混杂纤维的阻裂效果．研究结果表明，在小变形范围内，聚丙烯纤维与钢纤维对于提高承载能力具有协同效应，但该效应随着变形的增加而消失．尺寸大、弹性模量高的钢纤维相对于尺寸小的钢纤维或弹性模量低的聚丙烯纤维而言，对于提高水泥基复合材料的能量吸收能力具有更好的效果．研究表明，荷载———裂纹张开位移曲线呈现“宽峰”或“多峰”形式时，复合材料静态使用条件的确定必须综合考虑材料的极限荷载及相应的裂缝宽度．更多还原

【Abstract】 Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak" or “multi peaks" load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.更多还原