道面水泥混凝土气孔结构影响因素的试验研究

摘要

In order to explore influencing factors of air void parameters of pavement concrete,the experimental test of air content of freshly mixed concrete,curing period and vibrating time are carried to study the effects on the air void parameters ,the influence laws are analyzed.The experimental results show that four percent to six percent of the air content of freshly mixed concrete is reasonable ,too much air content count against the structure of air void.The air void parameters are mainly stable after twenty-two days' curing ,using test piece to observe will bring deviation.Prolong the curing period appropriately(thirty seconds) is favor to the formation of better structure of air void, especially for the upper level,however,vibrating excess sixty seconds is harmful to the structure of air void.%为了探究道面水泥混凝土气孔结构的影响因素，进行了新拌混凝土含气量、养护龄期、振捣时间对混凝土气泡特征参数的影响试验，分析了这三种因素的影响规律。结果表明：新拌混凝土含气量为4%~6%比较合理，过量引气不利于气孔结构的形成；气泡特征参数在从7~28 d时有较大变化，养护28 d时基本达到稳定，用早期龄期的试样观测会有误差；适当延长振捣时间（30 s）有利于硬化混凝土形成较好的气孔结构，尤其是对混凝土道面的上半层，可以有效地提高混凝土道面表面的抗冻性，但混凝土振捣时间超过60 s，对形成的气孔结构产生不利的影响。