Optimising Pervious Pavement Systems: A laboratory-based investigation of novel materials as water barrier/treatment systems

Pervious Pavement Systems (PPS) are an established stormwater control measure and provide an alternative to impervious surfaces due to their ability to control stormwater at the source. PPS treat pollutants and provide extra benefits such as water harvesting and mitigation of urban heat island effect (UHI), amongst others. However, the variability of rainfall patterns and the inability of pavement subsurface characteristics to deal with increasing rainfall volumes and intensities, underline the necessity for continuous optimisation. The significance of barrier/treatment systems, such as geotextiles in PPS, has been repeatedly reported with benefits such as increased structural integrity and pollutant retention, being particularly significant. However, the full impact of such barrier systems on peak flow delay and water retention in PPS is yet to be fully explored. The use of OASIS® phenolic foam in permeable paving for water management is a Coventry University invention designed to act as a barrier/treatment system, showing the potential to provide a significant hydraulic benefit. This enhancement is partly by an improvement in the water storage capacity of PPS due to its three-dimensional structure. This research fills a gap on optimisation and design of barrier systems utilised in PPS, with the main focus being on investigating the potential of OASIS® as an alternative to conventional geotextiles. This research has been done by examining the physical, mechanical, and hydraulic properties of OASIS® and by investigating any additional hydrologic benefit in PPS. This paper presents a laboratory study on PPS designs utilising OASIS® and Inbitex® geotextile against a variety of simulated climatic conditions with the aim being a contribution to flood prevention. Data acquired from the laboratory experiments showed higher water storage capacity and peak flow delay from PPS with OASIS® which supposes a hydrologic advantage, compared with a fluctuating hydraulic performance by Inbitex®.