桥梁下部结构混凝土抗渗性能研究

Research on impermeability of concrete of bridge substructure

选取粉煤灰掺量、外加剂类型为变量设计对照试验,进行8组试验进行混凝土抗渗性能试验,得出结论:各组试验试件在经过抗渗试验后,块截面大部分呈现干燥状态,渗水现象并不明显,试件渗水高度均在5~10 mm之间;当硅灰掺量的增加,混凝土抗渗性能先降低后升高,当粉煤灰掺量由10%增加至30%时平均渗水高度由4.5 mm升高至7.5 mm,抗渗性能降低66.7%;随着硅灰掺量的增加,混凝土抗渗性能先降低后升高,当粉煤灰掺量由30%提升至50%时平均渗水高度由7.5 mm降低至5.3 mm,抗渗性能降低29.3%;硅灰、粉煤灰作为外加剂时试件抗渗性能较差,当硅灰掺量为25%时,其抗渗性能相当于粉煤灰掺量为30%的对照组。

The amount of fly ash and the type of admixtures are selected as variables to design a control experiment,and 8 groups of experiments are carried out to conduct the concrete impermeability performance test.The following conclusions are drawn that after the impermeability test of each group of test specimens,most of the block sections are dry,the water seepage is not obvious,and the water seepage height of the specimens is between 5 mm and 10 mm.When the content of silica fume increases,the impermeability of concrete decreases first and then increases,and when the content of fly ash increases from 10%to 30%,the average water seepage height increases from 4.5 mm to 7.5 mm,and the impermeability decreases by 66.7%.With the increase of silica fume content,the impermeability of concrete first decreases and then increases.When the%increase to 50%,the average water seepage height is reduced from 7.5 mm to 5.3 mm,and the impermeability performance is reduced by 29.3%.When silica fume and fly ash are used as admixtures,the impermeability of the specimen is poor,and when the content of silica fume is 25%,its impermeability is equivalent to the control group with a fly ash content of 30%.