混凝土Cl^-渗透性快速测定方法研究

Accelerated Test of Chloride Permeability of Concrete

对快速测定混凝土C l-渗透性可行性及w/c、硅灰、粗集料最大粒径对C l-渗透性的影响进行了研究。结果证明,施加电势加速C l-迁移速率来测定混凝土C l-渗透性是可行的。C l-渗透性随w/c的增加而增加,掺入硅灰可以显著降低C l-渗透性,粗集料最大粒径对C l-渗透性有一定影响,但远远小于w/c的影响。掺入硅灰高强轻集料的混凝土C l-渗透性很低,尤其是采用全干轻集料配制的混凝土。利用快速测定法可有效评价混凝土C l-抗渗性等级。

The feasibility of accelerated chloride permeability test and the effect of w/c ratio,incorporation of silica fume,maximum aggregate size and aggregate type on the chloride permeability were studied.The mathematic analysis certifies that there is a linear relationship between accelerated test and natural diffusion.Test results show that the chloride permeability of concrete increases with w/c ratio whilst a limited amount of replacement of cement with silica fume,the chloride permeability decreases dramatically.The maximum aggregate size in the range of 8 to 25mm also seems to affect chloride permeability but at a much less significant level.The chloride permeability of silica fume lightweight aggregate concrete is very low,especially the concrete made with dry lightweight concrete.The chloride permeability can be evaluated by this accelerated test method.