摘要
为提升盾构管片质量,优选合成粗纤维,将4种性能的高强合成粗纤维分别与钢纤维混杂制备盾构管片混凝土,研究其强度、抗渗性和收缩变形,并通过孔结构和电镜观测分析微观结构。结果表明,对比钢纤维混凝土,钢⁃合成粗纤维混凝土的56d劈裂抗拉强度提升32.7%,氯离子抗渗性提高37.3%,达到标准规定的良好水平。混杂合成粗纤维增强了混凝土限制收缩的能力,早龄期的收缩变形降低约23%。毛细水吸附系数有所增大,总孔隙率增大4.9%,且主要增加了孔径>30nm的大孔,无论钢纤维还是合成粗纤维,纤维混凝土过渡区均较致密,纤维与水泥黏结良好。
In order to improve the quality of shield segments and optimize synthetic coarse fibers,four kinds of high⁃strength synthetic coarse fibers with different characteristics were mixed with steel fibers to prepare shield segment concrete.The strength,impermeability and shrinkage deformation were tested and studied,and the micro⁃structure was analyzed through hole structure and electron microscope observation.The results show that compared with steel fiber concrete,the splitting tensile strength of steel synthetic coarse fiber concrete increases by 32.7%in 56 days.Chloride ion impermeability increased by 37.3%,reaching the good level specified in the standard.The hybrid synthetic coarse fiber reinforced the shrinkage limiting ability of concrete,and the shrinkage deformation of early age decreased by about 23%.The capillary water adsorption coefficient increased,the total porosity increased by 4.9%,and the main increase was the micro⁃pores larger than 30nm.Whether steel fiber or synthetic coarse fiber,the transition zone of fiber concrete is relatively dense,and the bond between fiber and cement is fine.
作者
刘畅
贺智敏
邵旭阳
陈鑫
巴明芳
LIU Chang;HE Zhimin;SHAO Xuyang;CHEN Xin;BA Mingfang(School of Civil&Environmental Engineering and Geography Science,Ningbo University,Ningbo,Zhejiang 315211,China)
出处
《施工技术（中英文）》
CAS
2023年第17期123-130,共8页
Construction Technology
基金
浙江省自然科学基金(LY17E080007)
宁波大学滨海城市轨道交通协同创新中心开放基金(2020004)。
关键词
盾构管片
混凝土
钢纤维
合成粗纤维
力学性能
抗渗性
收缩
微观结构
shield segment
concrete
steel fiber
synthetic coarse fiber
mechanical properties
impermeability
shrinkage
micro⁃structure
