基于公路内养护混凝土预湿轻细骨料密实试验

Compaction test of pre wet lightweight fine aggregate based on highway curing concrete

探讨预湿轻细骨料在内养护混凝土中的微观结构及渗透性能,分别对其抗干缩、自收缩试验,氯离子扩散渗透试验、电测试试验及BSE图像观测试验等观察比较轻细骨料与普通混凝土微观结构及渗透性能。结果显示:内养护混凝土氯离子扩散系数及电通量均较普通混凝土高,但差异低于5%,表明混凝土中掺入预湿轻细骨料对其渗透性影响不大;酸性环境对氯离子渗透性能影响较大,BSE图像扫描显示,轻细骨料周围界面过渡区更加均匀致密,对内养护混凝土抗渗透性能具有较好的改善作用。

The microstructure and permeability of pre wet lightweight and fine aggregate in internal curing concrete are discussed.The microstructure and permeability of lightweight and fine aggregate andordinary concrete are observed and compared with those of ordinary concrete through dry shrinkage resistance,autogenous shrinkage test,chloride ion diffusion permeability test,electrical test and BSE image observation test.The results show that:the chloride diffusion coefficient and electric flux of internal curing concrete are higher than those of ordinary concrete,but the difference is less than 5%,which indicates that the pre wet lightweight fine aggregate has little influence on the permeability of concrete;the acid environment has a greater impact on the chloride ion permeability.BSE image scanning shows that the transition zone around the lightweight and fine aggregate is more uniform and dense,which has an impact on the impermeability of internal curing concrete It has a good improvement effect.