摘要
为降低机制砂混凝土的开裂敏感性,提高其应用技术水平,通过测试机制砂混凝土的干燥收缩值,并结合相应砂浆保水性和扫描电镜(SEM)微观形貌分析,研究了不同使用方式的减缩剂对石粉(SD)含量不同的机制砂混凝土干燥收缩的影响。结果表明,对于减缩剂使用方式不同的相同混凝土试件,内掺(SRA-M)和外涂(SRA-C)都降低了试件的干燥收缩,但对于不同的试件其降低幅度不同;对于减缩剂使用方式相同的不同混凝土试件,SRA-M更有利于降低石粉含量为5%的机制砂混凝土试件(5-SD)干燥收缩,而降低石粉含量为10%的机制砂混凝土试件(10-SD)干燥收缩更有效的减缩剂使用方式是SRA-C;减缩剂通过阻滞试件内部自由水分迁移渗出,提高其保水性,从而降低干燥收缩值。
In order to reduce the cracking sensitivity of concrete with manufactured-sand and enhance the application technology, the influence of shrinkage reducing admixture （SRA） in the different using-way on drying shrinkage of concrete with manufactured-sand containing the different stone dust （SD） content were studied by testing drying shrinkage of concrete with manufactured-sand and analyzing the water retention of mortar and microstructure of scanning electron microscope （SEM）. The results indicate that for the same concrete speci- men with SRA in the different using-way, the mixing with SRA （SRA-M） and coating with SRA （SRA-C） can decrease the drying shrinkage of the specimen, but the reductions of drying shrinkage are different for the different specimens; for the different concrete specimen with SRA in the same using-way, SRA-M is more conducive to reducing drying shrinkage of the concrete with manufactured-sand containing 5% of SD, and however, SRA-C corresponding to the concrete with manufactured-sand containing 10 % of SD; SRA can retard the migration seepage of internal free water, and thus improve the water retention to decrease drying shrinkage.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2013年第10期1399-1403,共5页
Journal of Functional Materials
基金
国家重点基础研究发展计划(973计划)资助项目(2001CB6100)
关键词
减缩剂
干燥收缩
机制砂混凝土
保水性
石粉
shrinkage reducing admixture
drying shrinkage
concrete with manufactured-sand
water retention
stone dust
