New Developments in Permeable Pavement Design to Improve Water Quantity and Quality

Pervious Pavements System (PPS) have been shown to possess a wide range of properties to effectively manage stormwater at source. The most popular PPS structure used in the UK and Spain consists of a permeable surface made of different materials such as interlocking concrete blocks, porous concrete, porous asphalt and reinforced grass, a base layer of aggregates, a sub-base layer of
gravel, and an intermediate layer of geotextile between the base and the sub-base layer. This paper reports on an investigation of the properties of a novel structure called OASIS® which was designed at Coventry University as an enhancement of the commercially available geotextiles when incorporated
in the PPS. The impact of OASIS® on the hydraulic behaviour of a PPS was analyzed through the study of infiltration rate, throughout the PPS and time required to reach the steady-state stage behaviour of the water within the PPS, under extreme rainfall intensities of 100 mm/hr, 200 mm/hr and 400 mm/hr, corresponding to a 100-year return period rainfall over duration of 15 minutes in different parts of the world. The result indicated that OASIS® provides an extra benefit when incorporated in PPS, delaying peak flow of a rainfall event by retaining and storing great volumes of water within its structure. These additional benefits are especially relevant under extreme rainfalls.