tailieunhanh - Academic Article: Hot Weather Comparative Heat Balances in Pervious Concrete and Impervious Concrete Pavement Systems

Academic Article: Hot Weather Comparative Heat Balances in Pervious Concrete and Impervious Concrete Pavement Systems focuses on a site in Iowa where both a pervious concrete and a traditional concrete paving system have been installed and where temperatures were recorded within the systems for extended time periods. The analyses cover days with negligible antecedent precipitation and high air temperatures, which are extreme conditions for UHI impact. | Academic Article Journal of Heat Island Institute International 2012 Hot Weather Comparative Heat Balances in Pervious Concrete and Impervious Concrete Pavement Systems John T. Kevern 1 Liv Haselbach 2 Vernon R. Schaefer 3 University of Missouri-Kansas City Kansas City MO USA 2Washington State University Pullman WA USA 3Iowa State University Ames IA USA Corresponding author email kevernj@ ABSTRACT Many pavements contribute to the urban heat island UHI effect due to their bulk mass and heat absorption capacities. Granular ground surfaces composed of soils or sands do not contribute to the UHI effect in a similar manner. Their porous nature may lessen the effect both with an increased insulating capacity and with an enhanced mechanism for evaporative cooling from absorbed water. Pervious concrete is a novel pavement that is being developed to aid in preventing stormwater-related environmental problems. Pervious concrete has a network of interconnected voids which allow water exfiltration to the subbase below. Limited studies indicate that a pervious concrete surface can have more elevated temperatures than those of similar traditional impervious pavements but also that temperatures are lower under the pavements. This study focuses on a site in Iowa where both a pervious concrete and a traditional concrete paving system have been installed and where temperatures were recorded within the systems for extended time periods. The analyses cover days with negligible antecedent precipitation and high air temperatures which are extreme conditions for UHI impact. This paper compares the increase in overall heat stored during several diurnal heating cycles in both of these systems. These analyses include not only the temperatures at various depths but also the heat stored based on the bulk mass of the various layers in each system and below grade. Results suggest that pervious concrete pavement systems store less energy than do traditional systems and can help .