高温作用对混杂纤维增强高延性水泥基复合材料拉伸性能的影响  

Effect of high temperature on the tensile properties of hybrid fiber reinforced high ductilitycementitous composites

作　　者：张聪[1,2] 夏超凡 袁振 李志华 ZHANG Cong;XIA Chaofan;YUAN Zhen;LI Zhihua(School of Environment and Civil Engineering, Jiangnan University, Wuxi 214000, China;State Key Laboratory of Green Building Materials, Beijing 100024, China)

机构地区：[1]江南大学,环境与土木工程学院,江苏无锡214000 [2]绿色建筑材料国家重点实验室,北京100024

出　　处：《功能材料》2020年第2期2007-2013,共7页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51908247);江苏省自然科学基金资助项目(BK20170192);绿色建筑材料国家重点实验室开放基金资助项目(YA-616)

摘　　要：高温是高延性水泥基复合材料(HDCC)在使用阶段可能遇到的最不利工况之一,但是目前对于HDCC高温性能的研究较为有限。对比研究了聚乙烯醇(PVA)纤维HDCC材料(PVA-HDCC)、钢纤维/PVA纤维混杂HDCC材料(HyHDCC-A)以及钢纤维/PVA纤维/碳酸钙晶须混杂HDCC材料(HyHDCC-B)在常温以及200、400、600和800℃高温作用后的拉伸性能。研究发现,常温下利用钢纤维等量替代PVA纤维将劣化PVA-HDCC的拉伸应变硬化能力,而引入碳酸钙晶须适量替代PVA纤维可以提高材料的拉伸强度、拉伸韧性,改善其应变硬化行为。高温对PVA-HDCC、HyHDCC-A与HyHDCC-B的拉伸强度和拉伸韧性均有明显的劣化作用,高温作用后均已不具备拉伸应变硬化能力;PVA-HDCC的拉伸强度与拉伸韧性随温度呈指数型衰减,钢纤维可以减缓HyHDCC-A与HyHDCC-B拉伸强度与拉伸韧性的衰减速率;碳酸钙晶须虽然可以提高HyHDCC-B高温作用后的拉伸强度值和拉伸韧性值,但并没有进一步减缓拉伸强度和拉伸韧性随温度的衰减速率。High temperature is one of most unfavourable conditions that the high ductility cementitious composite(HDCC)maybe suffer during its service period.However,relevant research on the high temperature property of HDCC is still limited.Tensile behaviours of polyvinyl alcohol fiber reinforced high ductility cementitious composites(PVA-HDCC),steel fiber/PVA fiber hybrid reinforced HDCC(HyHDCC-A)and steel fiber/PVA fiber/calcium carbonate whisker hybrid reinforced HDCC(HyHDCC-B)at room temperature and after 200℃,400℃,600℃and 800℃elevated temperature exposure were studied.The results indicate that equally replacing PVA fibers by steel fibers degraded the tensile hardening ability of PVA-HDCC at room temperature,while the addition of appropriate amount of calcium carbonate whisker improved the tensile strength,toughness and tensile strain hardening behaviour.The elevated temperature posed a significant effect on the tensile strength and toughness of PVA-HDCC,HyHDCC-A and HyHDCC-B.Tensile strain hardening behaviour of the three types of HDCCs was eliminated after high temperature exposure.Tensile strength and toughness of PVA-HDCC presented an exponential reduction along with the increase of temperature.The addition of steel fiber slowed down the reduction rate.Although the use of calcium carbonate whisker increased the post-temperature tensile strength and toughness of HyHDCC-B,the reduction rate was not further decreased.

关 键 词：高延性水泥基复合材料 混杂纤维 纤维水泥 高温 拉伸性能 

分 类 号：TU502[建筑科学—建筑技术科学]