摘要
To investigate the effect of fiber types on bending and tensile properties of high-strength,high-ductility cementitious composites( HS-HDCCs), ultra-high-molecular-weight polyethylene( PE) fibers,polyvinyl alcohol( PVA) fibers,and copper-plated micro steel fibers were selected as the reinforcement materials. The bending and tensile properties of HS-HDCCs with different fibers with a volume fraction of 2% were studied. The results indicate that PE,PVA,micro steel,and PVA-PE hybrid fibers impart varying degrees of toughening and improve the tensile strength. During the tensile and bending processes,HS-HDCCs with micro steel fibers exhibit a strain-softening phenomenon. HS-HDCCs with PVA fibers or with PVA-PE hybrid fibers can achieve multiple cracking behaviors and strain hardening phenomenon to a certain extent and show slight high-ductility characteristics. HS-HDCCs with PE fibers exhibit multiple cracking behavior and strain hardening phenomenon and show significant high-ductility characteristics. The test results can provide a basis for selecting fibers suitable for HS-HDCCs reinforcement.
为了考察纤维类型对高强高延性水泥基复合材料(HS-HDCC)弯曲与拉伸性能的影响,选取了超高分子量聚乙烯(PE)纤维、聚乙烯醇(PVA)纤维和镀铜微细钢纤维3种纤维在体积掺量为2%时,研究不同类型纤维对HS-HDCC的弯曲与拉伸性能的影响.结果表明:PE,PVA和微细钢纤维单掺或PVA-PE混杂,均对HS-HDCC有增韧和提高抗拉强度的效果.在弯曲和拉伸过程中,HS-HDCC单掺微细钢纤维时呈应变软化破坏;单掺PVA纤维和PVA-PE混杂可在一定程度上实现多缝开裂和应变硬化,有一定的高延性特性;单掺PE纤维可明显实现多缝开裂和应变硬化,有显著的高延性特性.研究结果为HS-HDCC优选合适的纤维提供了依据.
基金
The National Key Research and Development Program of China(No.2016YFC0401610)
the National Natural Science Foundation of China(No.51778133,51739008,51438003)
