不同气压环境下水工混凝土含气量发展规律研究  

Development Law of Air Content of Hydraulic Concrete under Different Air Pressure Environments

作　　者：代薇 杨淘 孙彦梅 张芮瑜 秦小枫 蔡君怡 李阳[2] DAI Wei;YANG Tao;SUN Yanmei;ZHANG Ruiyu;QIN Xiaofeng;CAI Junyi;LI Yang(China Yangtze River Power Co.,Ltd,Yibin 644612,China;College of Water Resources and Hydropower,Xi'an University of Technology,Xi'an 710032,China)

机构地区：[1]中国长江电力股份有限公司,宜宾644612 [2]西安理工大学水利水电学院,西安710032

出　　处：《硅酸盐通报》2025年第1期112-123,共12页Bulletin of the Chinese Ceramic Society

基　　金：三峡金沙江川云水电开发有限公司宜宾向家坝电厂资助(Z422302038)。

摘　　要：我国西南及西北部分地区具有较大的地势高差,气压相对较低,水工混凝土常常暴露在低气压环境下,导致其耐久性降低。本文研究了不同气压环境对水工混凝土含气量和引气剂溶液性能的影响。结果表明,低气压使引气剂溶液的引气能力明显减弱,气泡衰亡速率提高。极差和方差分析表明:在101和80 kPa环境中,各因素对含气量的影响程度由大到小排序为引气剂掺量、水胶比、粉煤灰掺量;而在50 kPa环境下,各因素对含气量的影响程度由大到小排序为水胶比、引气剂掺量、粉煤灰掺量。随着气压的降低,硬化混凝土含气量减小,低气压环境下的气泡更容易汇聚形成大气泡,水工混凝土硬化后气孔结构逐渐劣化,具体表现为试样孔隙结构劣化严重。同时,硬化混凝土的平均孔径和平均气孔间距系数增大,硬化混凝土含气量明显小于新拌混凝土含气量。低气压环境延缓了水泥水化过程,导致基体中气泡的稳定性降低,进而造成硬化混凝土含气量减少。Southwest and northwest part of China has a large terrain height difference,relatively low air pressure.Hydraulic concrete is often exposed to low air pressure environment,resulting in a reduction of its durability.This paper investigated the influences of different air pressure environments on air content of hydraulic concrete and the performance of air-entraining agent solution.The results show that low air pressure significantly weakens the air-entraining capacity of air-entraining agent solution,and the rate of bubble decay is higher.Range and variance analysis show that in 101 and 80 kPa environments,the degree of influence of each factor on air content is in descending order:air-entraining agent dosage,water-cement ratio,and fly ash dosage.In 50 kPa environment,the influence of each factor on air content is in descending order:water-cement ratio,air-entraining agent dosage,and fly ash dosage.With the reduction of air pressure,the air content of hardened concrete decreases,the bubbles in the low air pressure environment are more likely to converge to form large bubbles,and the pore structure of hydraulic concrete is gradually deteriorated after hardening,which is specifically reflected in the serious deterioration of the pore structure of the specimen.The average pore diameter and average pore spacing coefficient of hardened concrete increase,and the air content of hardened concrete is significantly smaller than that of fresh concrete.The low air pressure environment retards the cement hydration process,resulting in a decrease in the stability of bubbles in the matrix,which in turn causes a decrease in air content of hardened concrete.

关 键 词：水工混凝土 气压环境 引气剂 引气能力 孔隙结构 含气量 配合比参数 

分 类 号：TV431[水利工程—水工结构工程]