Pervious concrete is a unique and sustainable type of concrete typically with higher porosity than conventional concrete and consists of high void contents. The purpose of pervious concrete is to reduce surface storm water runoff and to revive ground water levels from precipitation and other similar sources by penetrating through its surface and into the ground as shown in the Figure 1 below. General, in order to achieve a sustainable pervious concrete, few percentages of or no fine aggregate is used with just enough cement and admixtures to hold the aggregate particles together making it lack in area of strength as a result of high void ratio contents in the concrete mix and therefore frequently used in areas with low traffic such as: parking lots, pedestrian pavements, conservatories and residential areas.

The porosity and penetration of water through pervious concrete

The pervious concrete has been widely used in paving projects around the U.S. including most regions of Arizona. However, it has not being generally accepted in the north mountain region of Arizona as part of paving materials due to the effect of freeze and thaw cycles on the performance of pervious concrete. As of 2009, Northern Arizona University started an asphalt paving project using pervious concrete for a parking lot construction. This project was to reach the goal of sustainability for the materials and ground water retention and it was the first pervious concrete project to be used for pavements in northern Arizona.  Unfortunately, the pervious concrete did not last longer than it was expected. Three years after the completion, the entire parking surfaces were in an irregular shape with pervious concrete smashing and significant displacements on the surface. The pervious concrete pavement had been exposed to be a safety concern among vehicles, bicycles, and pedestrians, so the university administration made a decision to replace it with conventional asphalt pavements in 2012. While the consulting firms, the university, and the materials suppliers in northern Arizona as a whole have been interested in finding a way to promote the use of pervious concrete in highway/street/parking lot paving, the promising solution has not yet found. The objective of this research project is to perform a preliminary investigation on pervious concrete mix design using local aggregate products. It is intended to determine pervious concrete mix design formulas as well as to produce promising and reliable pervious concrete mixtures.