What is the impact of permeable brick ratio on permeability rate?

In the production process of permeable bricks, the proportion of raw materials is quite important. The proportion of permeable bricks significantly affects their permeability rate, with aggregate gradation having a substantial impact on the surface permeability of the bricks. The water-cement ratio, sand-cement ratio, and gradation all influence the permeability rate of the base layer of the permeable bricks. Different gradations of the base layer can affect the overall permeability rate, necessitating manufacturers to strictly control the water-cement ratio, sand-cement ratio, and gradation to ensure high permeability rates and stable, reliable overall performance. The permeability rate of the surface layer of permeable bricks under different gradations. When the water-cement ratio and sand-cement ratio are the same, the aggregate gradation has a greater impact on the surface permeability rate of the bricks, meeting the permeability requirements of the permeable bricks.

Under the same grading condition and proportion distribution, concrete with fewer fine aggregate grades exhibits higher permeability than that with more fine aggregate grades. This is due to the fact that in continuous grading, the particles fill each other, and the voids of aggregates with more fine grades are fewer than those with fewer fine grades. Moreover, the specific surface area of the aggregates with more fine grades is larger than that of the aggregates with fewer fine grades, which increases the amount of cement used. This results in a lower connectivity of pores on the surface of the permeable bricks with more fine aggregates, leading to reduced permeability. Therefore, there exists an ideal mixing ratio in the continuous grading with fewer fine aggregate grades.