微细钢纤维自密实混凝土二次配合比设计新方法  

A New Two-Step Mix Proportion Design of Micro-steel Fiber Reinforced Self-compacting Concrete

作　　者：何小兵[1] 刘树鑫 刘亚 贾秋炳 HE Xiaobing;LIU Shuxin;LIU Ya;JIA Qiubing(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Hangzhou Institute of Communications Planning Design&Research,Hangzhou 310000,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]杭州市交通规划设计研究院,浙江杭州310000

出　　处：《建筑材料学报》2020年第1期56-63,共8页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51408091);重庆市基础研究与前沿探索面上项目(cstc2019jcyj-msxmX0744);中国博士后基金项目(2015M572641XB);重庆市教委科学技术研究项目(KJ1500512);山区桥梁与隧道国家重点实验室培育基地开放基金项目(CQSLBF-2015-12)

摘　　要：将微细钢纤维自密实混凝土(MSFRSCC)视作由满足一定填充能力和抗离析性能要求的基础自密实混凝土(SCC)与微细钢纤维净浆组成.在此基础上提出了采用基础SCC和钢纤维净浆制备MSFRSCC的二次配合比设计方法,并通过坍落扩展度和纤维特征值来确定该方法的适用范围,获得了MSFRSCC基本力学性能随纤维特征值变化的规律.结果表明:基于基础砂浆流变参数制备基础SCC,同时基于净浆平均裹浆厚度确定钢纤维净浆用量来最终制备MSFRSCC的方法,能够满足对MSFRSCC强度和工作性的预期;当纤维特征值不大于70.0%时,二次配合比设计方法能保证MSFRCC的工作性要求,且MSFRSCC的力学性能与纤维特征值线性相关度较高,可以基于基础SCC来预测其力学性能.The micro-steel fiber reinforced self-compacting concrete(MSFRSCC)is composed of self-compacting concrete(SCC)matrix and micro-steel fiber cement paste(MSFCP),which meets the requirements of filling capacity and anti-segregation,and MSFCP.A two-step synthesis method of MSFRCC mix design was proposed,which was made up of SCC matrix and MSFCP.The fiber eigenvalue threshold based on slump flow(SF)and fiber eigenvalue(the difference between slump flow and J ring slump flow)was employed to determine the application range of the two-step synthesis method,then mechanical properties of MSFRCC with fiber eigenvalue were obtained.The results show that SCC matrix prepared based on rheological parameters of the basic mortar that is derived from the SCC matrix,and steel fiber paste prepared based on the average paste film thickness is synthesized to obtain MSFRCC,which can meet expectations of strength and workability.When the fiber eigenvalue is not more than 70.0%,the two-step method can guarantee the workability of MSFRCC,and the linear correlation between the mechanical properties of MSFRSCC and the fiber eigenvalue is high,thus the mechanical properties can be predicted based on SCC.

关 键 词：微细钢纤维自密实混凝土 二次配合比设计 纤维特征值 净浆裹浆厚度 流变参数 

分 类 号：TU599[建筑科学—建筑技术科学]