高韧性聚丙烯纤维混凝土的配合比及力学性能试验研究  

Experimental Study on Blending Ratio and Mechanical Properties of High Toughness Polypropylene Fiber Concrete

作　　者：贾毅 宋浩博 柳其钱 白羽[1,2] 张品乐 JIA Yi;SONG Haobo;LIU Qiqian;BAI Yu;ZHANG Pinle(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,China;Earthquake Engineering Researching Center of Yunnan,Kunming 650500,China)

机构地区：[1]昆明理工大学建筑工程学院,昆明650500 [2]云南省抗震工程技术研究中心,昆明650500

出　　处：《材料导报》2024年第S02期647-651,共5页Materials Reports

基　　金：国家自然科学基金(52068037);云南省自然科学基金(140520210091);云南省博士后科研基金(109820210012)。

摘　　要：为制备出高韧性和高延展性的国产PP-ECC材料,基于正交试验的原理设计了16组PP-ECC配合比。对所有配合比组进行单轴拉伸试验,根据试验得到的应力-应变曲线结果确定了一组最优配合比,并对最优配合比的PP-ECC试件开展四点弯曲试验。最后通过电子显微镜观察对比了两种不同的PP纤维原材料和4种PP纤维的不同破坏方式。结果表明,第四组PP-ECC材料在单轴拉伸荷载作用下,具有优秀的应变硬化特征和多缝稳态开裂现象,极限拉应变稳定超过2.5%,且在试件四点弯曲试验中表现出超高的韧性。相比于国产PP纤维,日产PP纤维表面进行了化合处理,使纤维的表面能和粗糙度增大,从而使纤维与水泥基体的粘结强度增加。PP-ECC材料开裂破坏主要有纤维被拉断、纤维被拔出、纤维横跨裂缝和纤维与水泥基体脱粘四种破坏形式,其中纤维被拉断为主要破坏形式。In order to prepare domestic PP-ECC material with high toughness and high ductility,16 groups of PP-ECC mixing recipes were designed based on the principle of orthogonal test.Uniaxial tensile test was conducted on all the groups.According to the stress-strain curve results obtained by the test,a group of optimal mixing proportion was determined,and four-point bending test was carried out on PP-ECC specimens with the optimal mixing proportion.Finally two different PP fiber raw materials and four kinds of PP fiber were observed and compared by electron microscopy.The results showed that the fourth group of PP-ECC materials had excellent strain hardening characteristics and multi-crack steady-state cracking phenomenon under uniaxial tensile load,with its ultimate tensile strain stably maintained above 2.5%,and exhibited ultra-high toughness in four-point bending test.Compared with domestic PP fiber,the surface of PP fiber made in Japan has experienced surface chemical treatment,resulting in increased surface energy and roughness of the fiber,and enhanced bond strength between the fiber and the cement matrix.The cracking failure of PP-ECC material mainly includes fiber fracture,fiber pulled out,fiber lateral cracking,and fiber-matrix debonding,among which the fiber fracture is the main failure mode.

关 键 词：聚丙烯纤维 混凝土 正交试验 力学性能 应变硬化 最佳配比 微观分析 

分 类 号：TU502.6[建筑科学—建筑技术科学]