不同试验条件下水工混凝土含气特性试验研究  

Experimental Study on Aerated Characteristics of Hydraulic Concrete under Different Test Conditions

作　　者：闵永涛 陈双蛮 包想军 陈书军 韩养辉 曹郎郎 MIN Yongtao;CHEN Shuangman;BAO Xiangjun;CHEN Shujun;HAN Yanghui;CAO Langlang(PowerChina Northwest Engineering Corporation Limited,Xi'an 710100,China;PowerChina Sinohydro Bureau 3 Co.,Ltd.,Xi'an 710024,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710100 [2]中国水利水电第三工程局有限公司,西安710024

出　　处：《西北水电》2024年第1期14-19,共6页Northwest Hydropower

基　　金：国家自然科学基金(5207090694)。

摘　　要：为研究不同试验条件对水工混凝土拌和物含气量的影响,从环境温度、振实时间、单次拌和量3个方面,分析了试验条件对坍落度为50~70 mm的常态混凝土和140~160 mm的泵送混凝土含气量的影响。结果表明:环境温度与混凝土含气量成递减关系,当环境温度从10℃上升至35℃时,常态混凝土的含气量下降41.2%,泵送混凝土的含气量下降30.9%。含气量损失率随环境温度升高呈递增,当环境温度超过25℃时,含气量经时损失比较明显。随着混凝土振实时间延长,含气量呈下降趋势,当振实时间从5 s延长至30 s时,常态混凝土的含气量降低33.3%,泵送混凝土的含气量降低56.1%。混凝土含气量随单次拌和量增加而增大,当单次混凝土拌和量从搅拌机容量的20%增加至80%时,常态混凝土的含气量增加32.5%;泵送混凝土的含气量增加34.9%。研究结论可为现场施工及室内混凝土含气量控制提供参考依据。In order to study the influence of different test conditions on the air content of hydraulic concrete mixture,the influence of test conditions on the air content of normal concrete with slump of 50~70 mm and pumped concrete with slump of 140~160 mm is analyzed from three aspects of ambient temperature,compaction time and single mixing volume.The results show that the air content of concrete decreases with the ambient temperature.When the ambient temperature rises from 10℃to 35℃,the air content of normal concrete decreases by 41.2%,and the air content of pumped concrete decreases by 30.9%.The gas content loss rate increases with the increase of ambient temperature.When the ambient temperature exceeds 25℃,the gas content loss over time is more obvious.With the extension of concrete compaction time,the air content shows a downward trend.When the compaction time is extended from 5 s to 30 s,the air content of normal concrete decreases by 33.3%,and the air content of pumped concrete decreases by 56.1%.The air content of concrete increases with the increase of single mixing volume.When the single mixing volume of concrete increases from 20%of the mixer capacity to 80%,the air content of normal concrete increases by 32.5%and the air content of pumped concrete increased by 34.9%.The study result can provide a reference for on-site construction and indoor concrete air content control.

关 键 词：混凝土含气量 环境温度 振实时间 单次拌和量 

分 类 号：TV431[水利工程—水工结构工程]