超高性能混凝土的石英砂级配效应研究  

Quartz sand gradation effect of ultra-high performance concrete

作　　者：王威[1] 刘润清[1] 商晓阳 WANG Wei;LIU Runqing;SHANG Xiaoyang(Shenyang University of Science and Technology,Shenyang 110000,China)

机构地区：[1]沈阳理工大学,辽宁沈阳110000

出　　处：《混凝土》2024年第1期128-133,共6页Concrete

基　　金：国家自然科学基金(51972214);辽宁省高等学校创新团队(LT2019012)。

摘　　要：设计了单粒级配与连续级配两种方案,研究了石英砂级配对超高性能混凝土(UHPC)力学性能以及微观结构的影响,利用扫描电镜及压汞法对不同石英砂级配制备的UHPC试样微观形貌及孔结构进行分析。研究结果表明:当石英砂最大粒径小于0.63 mm时,UHPC抗折强度随石英砂最大粒径的增大而提高,但在超过0.63 mm后,抗折强度随最大粒径的增大而下降。并且在石英砂最大粒径相同时,连续级配与单粒级配相比,制备的UHPC抗折强度更高;UHPC抗压强度随石英砂最大粒径的增大而提高,且连续级配石英砂配制的UHPC抗压强度高于单粒级配;UHPC孔隙率随石英砂最大粒径的增大而减小,在最大粒径相同时,连续级配石英砂配制的UHPC具有更低的孔隙率与更合理的孔径分布,这是其表现出优异宏观力学性能的原因。Two schemes of single grain gradation and continuous gradation are designed,the effects of quartz sand grade on mechanical properties and microstructure of ultra-high performance concrete(UHPC)were studied.The microstructure and pore structure of UHPC samples prepared with different quartz sand gradations were analyzed by SEM and mercury injection method.The results show that when the maximum particle size of quartz sand is less than 0.63 mm,the flexural strength of UHPC increases with the increase of the maximum particle size of quartz sand,but when more than 0.63 mm,the flexural strength decreases with the increase of the maximum particle size.When the maximum particle size of quartz sand is the same,the flexural strength of UHPC prepared by continuous grading is higher than that of single grading.The compressive strength of UHPC increases with the increase of the maximum particle size of quartz sand,and the compressive strength of UHPC prepared by continuous graded quartz sand is higher than that of single particle gradation.The porosity of UHPC decreases with the increase of the maximum particle size of quartz sand.When the maximum particle size is the same,the UHPC prepared by continuous graded quartz sand has lower porosity and more reasonable pore size distribution,which is the reason for its excellent macroscopic mechanical properties.

关 键 词：级配 超高性能混凝土 力学性能 孔隙率 

分 类 号：TU528.041[建筑科学—建筑技术科学]