复合纤维混凝土的早期抗裂性能

Early Crack Resistance Performance of Composite Fibers Concrete

通过在水泥基体中加入纤维素纤维(CTF)、聚乙烯醇纤维(PF)、复合微筋纤维(VS)3种性能各异的纤维,分析了其单掺与混掺时混凝土的早期抗裂性能.结果表明:单掺时PF在3种纤维中对早期抗裂性能贡献最大,但混掺时CTF,VS可与PF形成互补,产生正混杂效应,其中CTF与PF共同遏制早期微裂纹的扩展,VS在微裂纹扩展为裂缝时发挥"桥接"作用,从而增强混凝土早期抗裂性能.研究结果可为研发高性能水泥基复合纤维材料提供参考.

By adding three different types of fibers,including cellulose fiber(CTF),polyvinyl-alcohol fiber(PF),and composite micro-reinforced fiber(various spray concrete,VS),into the cement matrix,the early crack resistance performance of the concrete under single addition and mixing addition was analyzed.The results show that when adding singly,PF contributes the most to the early crack resistance among the three types of fibers.However,CTF and VS can complement each other with PF,resulting in a positive hybrid effect,in which CTF and PF jointly restrain the early micro-crack growth,and VS plays a“bridge”role when the micro-cracks coalesce into cracks,thereby enhancing the early crack resistance of concrete.The research result can provide a reference for the development of high-performance cement-based composite fiber materials.