高频振捣对混凝土含气量和抗冻性的影响

试验采用3～4种水利水电工程常用的引气剂,配制水胶比为0.40、0.45和0.55的混凝土,检测高频振捣对混凝土含气量的影响.试验结果表明,混凝土的含气量受高频振捣的影响较大.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加;高频振捣时间相同时,含气量损失率随着水灰比的增加而增加.冻融试验的初步结果表明,水胶比为0.40时,随着高频振捣时间的延长,抗冻性差异不大,但也受引气剂品种的影响.本文的试验结果对工程施工人员正确认识高频振捣对引气混凝土性能的影响有一定的指导意义.

Effect of high-frequency vibration on concrete air content and frost resistance

The authors conducted an experiment to study the effect of high-frequency vibration on concrete air content and frost resistance.Four kinds of air-entraining admixtures which were frequently used in hydraulic projects were adopted.Concrete with w/c ratios of 0.40,0.45 and 0.55 were tested.The test results indicate that high-frequency vibration has a great effect on concrete air content.With similar w/c ratios,increase of vibration time will result in an increase of air loss ratio,and with similar vibration time concrete of a higher w/c ratio will have a higher air loss ratio.Freeze-thaw test results indicate that the frost resistance of concrete with a w/c ratio of 0.40 will present little change when the vibration time increases.It is believed that the test results of this paper can be instructive for project builders to properly understand the effect of high-frequency vibration on concrete properties.