混杂纤维增韧水泥基复合材料的静动态弯拉性能  

Static and Dynamic Flexural Properties of Hybrid Fiber-Toughing Cementitious Composites

作　　者：龙广成[1,2] 李承洋 张占森 杨恺 赵洪 朱德举 谢友均[1] 曾晓辉[1] LONG Guangcheng;LI Chengyang;ZHANG Zhansen;YANG Kai;ZHAO Hong;ZHU Deju;XIE Youjun;ZENG Xiaohui(School of Civil Engineering,Central South University,Changsha 410075,China;High-speed Railway Engineering Technology Research and Development Center,Shandong Railway Investment Holding Group Co.,LTD.,Jinan 250102,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]中南大学土木工程学院,长沙410075 [2]高速铁路工程技术研发中心,山东铁路投资控股集团有限公司,济南250102 [3]湖南大学土木工程学院,长沙410082

出　　处：《硅酸盐学报》2024年第2期592-602,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重大项目(A020204);山东铁投集团开放基金(TTKF2022-05)。

摘　　要：为了掌握钢纤维-聚乙烯纤维(PE纤维)混杂对水泥基材料静动态弯拉性能的影响规律,通过三点弯拉试验和落锤冲击试验方法,研究了钢-PE纤维混杂(掺量保持体积分数2.0%不变)增韧水泥基复合材料(HFTCC)的静动态弯拉性能,分析了钢纤维与PE纤维的混杂效应以及相应的增韧机理。结果表明:HFTCC静态弯拉性能与钢-PE纤维中PE纤维掺量正相关,而动态弯拉性能与钢纤维掺量表现出较强的正相关。1.5%(体积分数)PE纤维与0.5%钢纤维混杂表现出最佳的静态弯拉峰值应力;1.5%钢纤维0.5%PE纤维表现出最佳的动态弯拉能量吸收。在静态弯拉下,钢-PE混杂纤维相较于2.0%钢纤维对HFTCC峰值强度及能量吸收提升幅度分别为26.5%~31.7%与14.8%~56.8%;HFTCC的动态强度增长因子(DIF)与能量吸收表现出明显的应变率效应。钢纤维和PE纤维适当混杂可对HFTCC发挥较好的协同增强增韧效应,从而有效提升HFTCC的静动态弯拉性能。Introduction Cementitious materials are widely used in construction due to their wide range of raw material sources and easy construction.However,the characteristics of brittleness and easy cracking restrict their application in ductile structures.Fiber toughening is an effective approach to enhance the toughness of cementitious materials.The damage of cementitious materials is a gradual,multi-scale occurrence of the process.The first micrometer-scale cracks emerge,gradually expand and become larger with the increase of the load,forming the microscopic cracks,following convergence,developing macroscopic cracks,and ultimately leading to the material failure.Therefore,the toughening and crack-resisting effect of single-scale fibers are difficult to meet the multi-scale cracking process of cementitious composites.To correspond to this process,the hybrid fiber is an effective method,and the synergistic effect between different types of fibers can achieve the effect of“1+1>2”.There exist a few studies on the static flexural performance of hybrid fiber-toughing cementitious composites(HFTCC),but there is paucity of studies on the dynamic flexural behavior of HFTCC.To understand the hybrid effect of steel fiber and polyethylene fiber(PE fiber)on the static and dynamic flexural properties of cementitious composites,the static and dynamic flexural performances of HFTCC were investigated via three point bending test and drop weight impact test.In addition,the hybrid effect of steel fiber/PE fiber and the corresponding toughening mechanism were also analyzed.Methods The three-point bending tests were carried out based on a reference(GB/T 17671—2021).An electro-hydraulic servo universal testing machine(INSTRON 1342)was used to carry out the three-point bending test,at a loading rate of 0.2 mm/min.Load transducers and displacement sensor were used to record the load and mid-span deflection(δ)changes during the test,and the loading was stopped when theδvalue reached 5 mm.The impact flexural properties were determined b

关 键 词：水泥基复合材料 混杂纤维增韧 静动态弯拉性能 弯曲韧性 

分 类 号：TU528[建筑科学—建筑技术科学]