Alleviating urban heat island effect using high-conductivity permeable concrete pavement

Abstract

Abstract This paper investigated the potential of using high-conductivity permeable concrete pavement in alleviating urban heat island (UHI) effect in both dry and wet conditions. The high-conductivity permeable concrete was prepared by adding steel fibers into traditional permeable concrete. Laboratory tests were conducted to backcalculate thermal conductivity of permeable concrete using the measured temperature files and thermal transfer models. The indoor experiments with controlled thermal radiation and water spray were conducted to measure surface temperatures of permeable concrete slabs in dry and wet conditions. Finite element models were developed to simulate thermal behavior of permeable concrete pavement and the simulation model results were found in good agreement with the indoor temperature measurements. The results showed that the permeable concrete slabs have the higher surface temperature than conventional concrete slab in dry conditions, but similar or lower surface temperatures in the wet condition, depending on water evaporation rate. The peak surface temperature of high-conductivity permeable concrete was 1–3 °C lower than that of conventional permeable concrete due to high thermal condition. The simulation results of outdoor environment show that permeable concrete pavement caused slightly greater heat output on sunny days but much smaller heat output on rainy days to the near-surface environment, as compared to conventional concrete pavement. The increase of thermal conductivity of permeable pavement can further reduce the heat output by 2.5–5.2%. The study findings prove that the high-conductivity permeable concrete is an effective method to alleviate UHI effect in dry and wet conditions.