多尺度聚丙烯纤维混凝土抗裂性能的试验研究  

Experimental study of crack resistance for multi-scale polypropylene fiber reinforced concrete

作　　者：梁宁慧[1] 刘新荣[1] 孙霁[1] 

机构地区：[1]重庆大学土木工程学院山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《煤炭学报》2012年第8期1304-1309,共6页Journal of China Coal Society

基　　金：中央高校基本科研业务费科研专项自然科学类资助项目(CDJZR11200002);国家自然科学基金创新群体基金资助项目(50921063);重庆市科技攻关计划资助项目(CSTC 2011AC6159)

摘　　要：选用4种尺寸的聚丙烯细纤维与2种尺寸的聚丙烯粗纤维,在相同拌合工艺、相同配合比条件下进行单掺及混掺混凝土的开裂性试验。试验表明:对聚丙烯纤维,同掺量时,长径比较小者,早期抗裂效果相对较优;细纤维在塑性态混凝土中的阻裂效应优于粗纤维;粗纤维在硬化阶段的抗裂效果优于细纤维。鉴于此结果,将聚丙烯粗细纤维进行混掺,使其在混凝土凝结硬化的不同时期能协同作用,不仅能够阻止混凝土的塑性开裂,而且可推迟硬化阶段裂缝的形成,从而有效控制混凝土裂缝,达到阶段抗裂、层次抗裂的目的。Cracking tests of fine polypropyleue fibers in four sizes and thick polypropylene fibers in two sizes, sing- doped and mix-doped with concrete by same mixing technique and in same dose ratio, were completed. The results show that, under the same dosage, the smaller the aspect ratio is, the better the effect on early cracking is ; the crack-re- sist effect of fine fibers in plastic phase of concrete is better than that of the thick ones ; the crack-resistant effect of thick fibers during hardening phase is better than that of the fine ones. According to the above, the mixed blend of fine and thick polypropylene fibers will display different functions during diverse hardening phases, and it will not only pre- vent plastic cracking of the concrete, but also delay the cracks formation, so as to effectively reduce cracks and reach the crack-resist purposes in different phases and levels.

关 键 词：多尺度 聚丙烯纤维 塑性态混凝土 阻裂效应 

分 类 号：TU528.01[建筑科学—建筑技术科学]