摘要
为研究预加荷载作用下聚丙烯纤维混凝土(polypropylene fiber reinforced concrete,PFRC)的抗渗性能,选用1种聚丙烯粗纤维和2种聚丙烯细纤维进行单掺和混掺,在5种荷载水平下进行了氯离子扩散系数试验,分析了不同混掺比例下PFRC试件在不同荷载水平作用下的氯离子扩散系数变化规律.采用压汞法和电镜扫描研究了纤维混掺和荷载大小对混凝土微观孔结构的影响.结果表明:在5种轴向荷载水平下混掺多尺寸PFRC试件A8的氯离子扩散系数分别降低了93.9%、90.8%、77.5%、63.5%和66.5%,均为降低幅度最大的一组,混掺PFRC的抗渗性能优于素混凝土和单掺PFRC;同时粗细纤维混掺可以形成三维空间网架结构,能在不同阶段产生协同作用,有效地提高混凝土在不同荷载水平作用下的抗渗性能.
To study the anti-permeability mechanism of polypropylene fiber reinforced concrete(PFRC)under preloading,one type of coarse polypropylene fiber and two types of fine polypropylene fibers were selected to add into concrete.The diffusion coefficient of chloride ion of hybrid PFRC under five different preloading levels was analyzed by chloride diffusion coefficient test.The mercury intrusion porosimetry(MIP)and the scanning electron microscopy(SEM)were used to investigate the effect of fiber hybridization and preloading level on the micropore structure and permeability of concrete.The test results showed that the chloride diffusion coefficient of PFRC specimen A8 under five preloading levels decreased by 93.9%,90.8%,77.5%,63.5%and 66.5%,respectively,all of which have the largest reduction,indicating that the anti-chloride ion permeability of hybrid PFRC was superior to plain concrete and the concrete reinforced with one kind of fiber.Moreover,multi-scale fiber hybridization with coarse and fine fibers can form a three-dimensional spatial network structure,resulting in a synergistic effect at different levels,and the anti-permeability of concrete under different loading levels was effectively improved.
作者
梁宁慧
严如
田硕
刘新荣
许益华
郭哲奇
LIANG Ninghui;YAN Ru;TIAN Shuo;LIU Xinrong;XU Yihua;GUO Zheqi(College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education(Chongqing University),Chongqing 400030,China)
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第9期155-162,共8页
Journal of Hunan University:Natural Sciences
基金
国家自然科学基金资助项目(41772319)
重庆市研究生科研创新项目(CYS19005)。
关键词
聚丙烯纤维混凝土
混掺
抗渗性能
预加荷载
氯离子
polypropylene fiber reinforced concrete(PFRC)
hybridization
impermeability
preloading
chloride ion
