胶砂比对UHPC高温力学性能及微观结构的影响  

Effect of Binder-sand Ratio on High-temperature Mechanical Properties and Microstructure of UHPC

作　　者：王宏 王丹丹 朱平 何长龙 王桂敏 盖梅香 孙晓光 WANG Hong;WANG Dan-dan;ZHU Ping;HE Chang-long;WANG Gui-min;GAI Mei-xiang;SUN Xiao-guang(China Construction Port Group Co.,Ltd.,Qingdao 266032,China;Qingdao Hailutong Engineering Quality Inspection Co.,Ltd.,Qingdao 266032,China;Qingjian Group Co.,Ltd.,Qingdao 266071,China)

机构地区：[1]中建筑港集团有限公司,山东青岛266032 [2]青岛海陆通工程质量检测有限公司,山东青岛266032 [3]青建集团股份公司,山东青岛266071

出　　处：《混凝土与水泥制品》2022年第7期14-19,共6页China Concrete and Cement Products

基　　金：河北省科技厅重点研发计划项目(20373802D);河北省教育厅自然科学重点项目(ZD2017223)。

摘　　要：利用铁尾矿砂制备了超高性能混凝土(UHPC),研究了在高温环境下不同胶砂比(1∶0.8、1∶0.9、1:1.0、1∶1.1)对UHPC试件力学性能的影响,测定了高温下UHPC的孔结构,并用SEM表征了UHPC的微观结构,探讨了胶砂比对UHPC高温性能影响的机理。结果表明,随着温度的不断升高,不同胶砂比的UHPC力学性能出现了不同程度的下降,其中,胶砂比为1∶1.0的UHPC在各个目标温度下均表现出相对较高的力学性能;微观分析表明胶砂比为1∶1.0的UHPC基体比胶砂比为1∶0.8的UHPC基体更加密实,在高温作用下裂缝宽度更小,且基体与钢纤维的结合能力更强,有效降低了钢纤维在高温下的破坏程度。Ultra-high performance concrete(UHPC)was prepared by iron tailings sand.The effect of different binder-sand ratio(1∶0.8,1∶0.9,1∶1.0,1∶1.1)on the mechanical properties of UHPC at high temperature was studied.The pore structure of UHPC at high temperature was determined.The microstructure of UHPC was charactered by SEM,and the mechanism of the effect of binder-sand ratio on the high temperature properties of UHPC was discussed.The results show that with the increase of temperature,the mechanical properties of UHPC with different binder-sand ratio decrease in varying degrees,and the UHPC with 1∶1.0 binder-sand ratio shows relatively high mechanical properties at each target temperature.Pore structure and SEM analysis show that UHPC matrix with 1∶1.0 binder-sand ratio is denser than UHPC matrix with 1∶0.8 binder-sand ratio,and crack width is smaller under high temperature.In addition,UHPC matrix with 1∶1.0 binder-sand ratio has stronger bonding ability with steel fiber,which effectively reduces the damage degree of steel fiber at high temperature.

关 键 词：胶砂比 超高性能混凝土 高温 力学性能 微观结构 裂缝 

分 类 号：TU528[建筑科学—建筑技术科学]