Thermophysical Optimization of Specialized Concrete Pavement Materials for Collection of Surface Heat Energy and Applications for Shallow Heat Storage

Great potential exists to use pavement structures to collect or store solar energy for heating and cooling of adjacent buildings, for example, airport terminals and shopping malls. Therefore, pavement materials comprising both conventional and unconventional concrete mixtures with a wide range of densities, thermal conductivities, specific heat capacities, and thermal diffusivities were investigated. The thermophysical properties were then used as inputs to a one-dimensional transient heat transport model to evaluate temperature changes at various depths at which heat might be abstracted or stored. Results indicated that a high diffusivity pavement (e.g., one that incorporated high conductive aggregates or metallic fibers, or both) could significantly enhance heat transfer as well as reduce thermal stresses across the concrete slab. However, a low diffusivity concrete could induce a more stable temperature at shallower depths and enable easier heat storage in the pavement, which would help to reduce the risk of damage caused by freeze–thaw cycling in cold regions.