213 E. Locust Street; 815-756-2319

Friday, November 21, 2008

Permeable Brick Pavement

While walking through our new parking lot, you may notice a difference between the sidewalk brick and the pavement brick. There are numerous differences, both that you can and can't see:

1) The pavement (vehicular) brick is 1/2" thicker than the sidewalk brick. Just as asphalt or concrete pavement is thicker than concrete sidewalk, we do the same here to create a stronger material for cars to drive on.

2) The pavement brick has a subbase made entirely of stone. There is 1' of stone that is 1" to 3" in size, which is capped by stone that is up to 3/4" in size, which is then capped by an even smaller chip. Then the brick goes on top of this. The sidewalk bricks are placed on a 5" concrete underlayement. I'll explain the stone subbase in a moment.

3) The sidewalk bricks are closer together than the pavement bricks. This is due to the size of the "nubs" that are on the sides of the bricks.

4) The sidewalk bricks are filled in with sand. The pavement bricks are filled in with a colored granite chip.

The reason for all these differences is that the pavement brick pavement system is permeable (aka, water can drain through). The larger voids between each brick allow for water to trickle through the granite chips and then into the stone subbase. There are several hundred feet of underdrains throughout the parking lot which drain the water into the structures and on to the storm sewer system.

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