With growing urban populations, methods of reducing the urban heat island effect have become increasingly important. Cool pavements altering the heat storage of materials used in pavements can lead to lower surface temperatures and reduce the thermal radiation emitted to the atmosphere. Cool pavement technologies utilize various strategies to reduce the temperature of new and existing pavements, including increased albedo, evaporative cooling, and reduced heat conduction. This process of negative radiation forces helps offset the impacts of increasing atmospheric temperatures. This paper presents an extensive analysis of the state of the art of cool pavements. The properties and principles of cool pavements are reviewed, including reflectivity, thermal emittance, heat transfer, thermal capacity, and permeability. The different types, research directions, and applications of reflective pavements are outlined and discussed. Maintenance and restoration technologies of cool pavements are reviewed, including permeable pavements. Results show that cool pavements have significant temperature reduction potential in the urban environment. This research is important for policy actions of the European Union, noting that European and international business stakeholders have recently expressed their interest in new ways of reducing energy consumption through technologically advanced pavements.

Giorgos Panaras (Department of Mechanical Engineering, University of Western Macedonia), John A. Paravantis (Department of International and European Studies, University of Piraeus), Evanthie Michalena (Sustainability Research Centre, University of the Sunshine Coast), Jeremy Maxwell Hills (Sustainability Research Centre, University of the Sunshine Coast and Institute of Marine Resources, Faculty of Science, Technology and Environment, The University of the South Pacific), Andreas P. Vouros (Department of Mechanical Engineering & Aeronautics, University of Patras), Aikaterini Ntymenou (Department of Environmental Engineering, University of Patras), and Giouli Mihalakakou (Department of Mechanical Engineering & Aeronautics, University of Patras)

Kappou, S., Souliotis, M., Papaefthimiou, S., Panaras, G., Paravantis, J. A., Michalena, E., Hills, J. M., Vouros, A. P., Ntymenou, A., & Mihalakakou, G. (2022). Cool Pavements: State of the Art and New Technologies. Sustainability, 14(9), 5159. https://doi.org/10.3390/su14095159