速凝剂种类对钢纤维喷射混凝土力学及界面性能影响  

Mechanical and Interface Properties of Steel Fiber Reinforced Shotcrete Containing Different Setting Accelerators

作　　者：曾鲁平 乔敏 王伟 赵爽 张小磊 冉千平 洪锦祥 ZENG Luping;QIAO Min;WANG Wei;ZHAO Shuang;ZHANG Xiaolei;RAN Qianping;HONG Jinxiang(State Key Laboratory of High Performance Civil Engineering Materials,Jiangsu Sobute New Materials Co.,Ltd.,Nanjing 211103,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]高性能土木工程材料国家重点实验室,江苏苏博特新材料股份有限公司,南京211103 [2]东南大学材料科学与工程学院,南京211189

出　　处：《硅酸盐学报》2020年第5期659-664,共6页Journal of The Chinese Ceramic Society

基　　金：国家重点研发计划(2017YFB0310100);中国铁路总公司科技研究开发计划课题(AF1018G030);江苏省第十五批六大人才高峰项目(JZ-058);江苏省333高层次人才培养工程科研项目(BRA2018202)资助。

摘　　要：采用三分点加载法系统地评价了液体速凝剂种类对喷射大板成型钢纤维混凝土的力学强度与弯曲韧性行为的影响,设计同配比钢纤维砂浆体系,从早期力学强度发展与钢纤维-水泥基体微观界面方面探究了液体速凝剂种类对钢纤维增韧作用的影响机理,结果表明:相对于有碱速凝剂,无碱速凝剂的掺入对混凝土基体后期强度影响较小,有利于发挥钢纤维的增韧抗弯作用,体系荷载-挠度曲线更为饱满;从早期力学强度发展角度,无碱速凝剂通过促进短柱状钙矾石与纤维针状C-S-H凝胶的早期水化环境形成,有效地改善了水泥基体与钢纤维的界面粘结效果,有利于提高钢纤维喷射混凝土的早期初期支护能力。The mechanical properties and flexural toughness behaviors of steel fiber reinforced shotcrete containing different liquid setting accerlerators were evaluated by a three-pointing loading method.To clarify the working mechanism of liquid setting accelerators on the toughness properties of steel fiber,the early-age strength development and steel fiber-cement matrix interface area micromorphology of steel fiber reinforced mortar with the similar material composition were investigated.The results show that the long-term mechanical strength of steel fiber reinforced shotcrete with alkali-free accelerator is greater than that with alkaline setting accelerator,thus leading to a full loading-deflection curve and better toughness enhancement effect of steel fiber.For the early-age strength development,short prismatic ettringite and needle-like C-S-H gel appear after introducing alkali-free setting accelerator,thus inducing the better bonding strength between steel fiber and cement matrix and improving the initial support capacity of steel fiber reinforced shotcrete.

关 键 词：钢纤维喷射混凝土 液体速凝剂 荷载-挠度 粘结界面区 

分 类 号：TU528.53[建筑科学—建筑技术科学]