Harnessing Benefits of Pervious Concrete Pavements: A Novel UHI Mitigation Strategy

Abstract

With growing urbanization and associated development of infrastructure, urban heat islands (UHI) have emerged as major challenges, which need to be taken care of, in order to endure sustainable urban conglomerates. In this study, pervious concrete pavements (PCP) systems were designed and constructed to assess if they can serve as best UHI management practices through actual field implementation and testing. A systematic field experimental program was devised, wherein temperature profiles were measured across the depth of PCPs, under both dry and wet conditions. Thermocouples were embedded in PCP and Portland cement concrete pavements (PCCP) to record and compare the temperature profiles. The pavement surface temperature was recorded at 15-minute intervals under dry conditions, while the pavement temperature was examined after every three hours for wet conditions. Wet conditions were simulated by pouring water over the pavements and the temperatures across the pavement thickness were measured. The quantity of water required to decrease the pavement temperature by 1 °C across the depth of the pavements was quantified. Under dry conditions, it was found that PCP system was warmer compared to PCCP, irrespective of the time in one day. The volume of water required was about 38 ml to reduce the surface temperature of PCP by 1 °C. Further, in order to achieve similar reduction in temperature throughout the thickness of the pavement system, the volume of water required ranged from 2620 to 6350 ml. Owing to its impervious nature, no change in temperature was observed in PCCP system even with inundation of water, except at the surface that exhibited very minute reduction. The experimental findings showed that negative impacts of UHI can be countered by using PCP systems as a potential for harnessing evaporative cooling effects that is remarkably higher than conventional pavements.