高频振捣对混凝土含气量、抗冻性和气泡参数的影响  

Influence of high-frequency vibraiton on concrete air content,antifreeze and air bubble parameters

作　　者：刘艳霞[1] 陈改新[1] 鲁一晖[1] 

机构地区：[1]中国水利水电科学研究院结构材料研究所,北京100038

出　　处：《水力发电学报》2009年第3期106-111,共6页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(50579075);水利部公益性行业科研项目(200701041)

摘　　要：采用水利水电工程常用的4种引气剂,配制水胶比为0.40、0.45和0.55的二级配混凝土,检测高频振捣对混凝土含气量和抗冻性的影响。结果表明,水胶比相同时,含气量损失率基本上随着高频振捣时间的延长而增大;高频振捣时间相同时,含气量损失率随着水胶比的增大而增大。水胶比为0.40时,掺加优质引气剂的混凝土的抗冻性对高频振捣并不敏感;水胶比为0.45时,高频振捣60s和90s后混凝土的抗冻性明显下降;水胶比增加至0.55时,混凝土的抗冻性随着高频振捣时间的延长迅速下降。同时,高频振捣对混凝土的气泡参数有明显的负面影响。根据试验结果,对混凝土的高频振捣时间提出要求,供施工参考。Four kinds of air-entraining agent which are frequently used for hydraulic projects are adopted in the experiments. Concrete made with w/（ c ＋ f） ratios of 0.40, 0.45 and 0.55 are subjected to high-frequency vibrations. The test results indicate that the high-frequency vibration has a great effect on concrete air content. At the same w/（ c ＋ f） ratio, the more vibration time, the more air content loss ratio; and at the same vibration time, concrete with a higher w/（ c ＋ f） ratio has a higher air content loss ratio. At aw/（ c ＋ f） ratio of 0.40, antifreeze of concrete made with high-quality air-entraining agent is not sensitive to high-frequency vibration; at a w/（ c ＋ f） ratio of 0.45, antifreeze of concrete is obviously decreased in vibration time of 60s and 90s; when w/（ c ＋ f） ratio is further increased to 0.55, antifreeze of concrete is quickly dropped with increase of vibration time. At the same time, high-frequency vibration also has obvious adverse effect on concrete air bubble parameters. From above test results, appropriate high-frequency vibration time is proposed.

关 键 词：水土材料 抗冻性 高频振捣 混凝土 引气剂 含气量 气泡参数 

分 类 号：TV43[水利工程—水工结构工程]