Besides having the regular concrete or asphalt pavement, you also have the option to go the permeable way. Permeable pavements are on the rise today because of its ability to allow water to go through the surface and be absorbed by the soil underneath. Because the layer is permeable, it can be expected that no flooding will occur unless the place is under a huge hurricane or typhoon. In addition to managing storm water, it also allows air and sunlight to penetrate the soil under the pavement later nourishing the roots of trees and grass around the area. In addition, the water or snow that has gone through the permeable surface can recharge the underground water system that naturally occurs.
So, what are the types of permeable pavements?
The regular non-porous concrete uses a mixture of coarse gravel, fine gravel, cement, water, and other additives. The fine material added to the concrete mixture makes the cement impervious to water or non-permeable to water. In order to achieve a porous or permeable concrete, the fine material is reduced to a substantial level or is totally removed. With the absence of fines, a 15% to 25% permeable surface may be achieved. This will allow an average of 480 in/hour of water flow. Because the surface of this concrete is porous and permeable, it is to be expected that it will not show the same smoothness as when the fines are added to the mix.
This asphalt technology was developed in the 1970’s. Just like concrete, the fines are removed from the mixture so to create voids and air gaps that will make the asphalt surface permeable to water. Large aggregates are also added to the mix to create and increase the void space. To avoid any asphalt binder to move and cover air spaces, additional additives and binders are poured into the mix to avoid migration of binders. This will reinforce the fiber and assist with cohesion leaving the air gaps intact and unclogged.
If you have seen pathways or driveways made of a brick-looking material, then you are looking at a concrete paver driveway. This type of driveway is semi or partially permeable. The spaces in between the blocks can be filled with grass or gravel, which offers a different kind of finish. This type of permeable pavement is only recommended for low traffic areas like footpaths and driveways. It is not recommended for highways and busy streets.
There are other permeable materials that you can use to make your driveway more environmentally friendly than before. Other types of permeable pavements are turf reinforcing grid, decks, open graded aggregate, and soft paving materials (wood mulch). Because it is not as compact as the regular concrete or asphalt installation, it is recommended that this type of pavement be cared for properly and regularly. Without proper care, it will not last as long as it should be, which is for 20 years.