Effect of gradation of mineral admixtures on chloride permeability of concrete

We researched the permeability of different mix proportion. We compared the grading curve of the optimal grading by theoretical calculation (including aggregate and gelled material) and there mixture ratio of test. And we compared the permeability of different mixture ratio. We draws the following conclusions: Permeability of concrete with long age has close relationship with gradation including aggregate and gelled material. Dosage of mineral admixtures has no big effect on permeability, while the proportion of different mineral admixture has big. The limestone powder content had the greatest influence to permeability by gradation, so increasing its content instead part of cement within certain range could increase the ability of permeability resistance.