Lightweight pervious concrete tackles urban heat

A new study published in the International Journal of Pavement Engineering has shown how lightweight pervious concrete could help mitigate the urban heat island (UHI) effect by storing and releasing heat more efficiently.

The research, led by Dr. Emad Yaghmour and colleagues, investigated the use of lightweight aggregates and phase change materials (PCMs) in pervious concrete to create a thermal energy storage system within pavements.

Pervious concrete is a form of concrete that contains little or no sand, giving it a porous structure that allows water and air to pass through. It is commonly used in low-traffic areas such as car parks and pavements to manage surface water and reduce flooding. The material’s open voids also make it a promising candidate for passive heat regulation in urban environments.

The study examined how changes in aggregate type, replacement ratios, and water-to-cement ratios affect both the mechanical and thermal performance of the concrete. Tests found that while lightweight aggregates with higher crushing resistance reduced compressive strength, they significantly increased thermal storage capacity, allowing the material to absorb and release heat more effectively.

The mix containing “LWA2” aggregates achieved the highest recorded capacity of 45 MJ/m³, indicating strong potential for low-traffic applications such as pavements, cycleways and public squares. The researchers suggest the material could help reduce surface temperatures, lower surrounding air temperatures, and cut energy use in dense city areas.

The study’s authors describe the innovation as a potential tool for sustainable urban design, helping cities combat the combined impacts of heat, pollution and increased energy demand.

The research was funded by the US Department of Energy (Award No. DE-FE0031886) and carried out by a multidisciplinary team including Emad Yaghmour, Mu’ath Abu Qamar, Clay Naito, Muhannad Suleiman, John Fox, Carlos Romero and Sudhakar Neti.

Read the full paper at tandfonline.com/study