Is Pervious Concrete Strong Enough
Thus far it has been difficult to quantify the strength of pervious concrete. We have installed thicknesses of 6″ through 10″, and have found that with the correct mix and placement it has lasted for many years. We offer a 10 year limited warranty.
Ultimate endurance of Pervious Concrete is dependant upon a well compacted porous base, fast, but controlled placement, uniform compaction and correct control joints. These factors control raveling and cracking. (At present Pervious Concrete is not recommended for high speed, high traffic roads.)
To understand why Pervious Concrete is so strong, consider that the aggregate used is crushed, not round. This means that under compaction there is more contact between rough surfaces. The voids are like a honeycomb that creates unusual structural strength. (River gravel is not a suitable aggregate in pervious concrete.)
Though lime rock has been the preferred aggregate for Pervious Concrete over the past few years as older sources have played out, newer sources have often provided rock with less integral strength. This rock often crumbles in transit, producing fines that reduce the porosity of the Pervious Concrete.
For this reason we are regularly using granite aggregate which is stronger and provides greater strength, which is especially desirable when truck traffic is anticipated. We have more than 25 years working experience with Pervious Concrete that is why we know it stands up when properly engineered and installed for its intended end use. We have several installations that stand up to truck traffic every day, albeit at low speeds.