Proper drainage is important to ensure a long-lasting and durable Plant City parking lot paving. Moisture accumulation in any part of the pavement can weaken the structure of the pavement and cause structure damages.
A simple moisture problem can weaken the subgrade and aggregate base layer by increasing pore pressure and reducing the materials’ resistance to shear.
There are other instances, too, when the soil heaves up as the underlying soil expands. This is caused when the soil is moist and it’s the type that expands to the surface.
Moisture in the hot mix asphalt layers can also cause stripping because instead of the asphalt binder, it will adhere to the aggregate particles. The sources of moisture are typically rainwater, runoff, and high groundwater. There is no way to prevent rainwater or even runoff.
The only way to protect your pavement from this is through surface drainage and subsurface drainage. It is cost-effective to put measures into place that will prevent moisture entry and accumulation using surface drainage than to simply remove the moisture using subsurface drainage.
Surface drainage is the most popular system of removing all the water that is present on the pavement surface, shoulder surface, or any other surface from which water may flow onto the pavement. If not removed, this water may accumulate underneath and weaken the pavement structure.
Here are the three primary means used to prevent water infiltration and accumulation:
HMA can be impermeable when it is properly compacted and applied. When the air voids are below 8 percent, there is a smaller chance for water and moisture to get into the surface layer of the asphalt. Minor cracks appearing on the HMA should be addressed immediately because these are where water can get in.
The main pavement section should be sloped towards both the edges of the pavement so water will flow freely and easily. Rainwater will flow much quicker to the edge where it is then typically collected in a curb, gutter system, or roadside ditch. The standard for the slope should be about 2 percent cross slope.
The curb, gutter system, or roadside ditch should be properly graded to allow the water to flow to general collection points such as the catch basins or detention pods. The generally accepted standard is a grade of 0.5 percent or more although lesser grades have been used effectively in many curbs, gutter systems, and roadside ditches.