Modeling the Interface Shear Strength of Asphalt Pavements Containing a Solar Collector

Interface shear strength of road pavements plays a crucial role on overall structural performance. Interface between asphalt layers is commonly treated by applying a bituminous tack coat emulsion. Specific pavement structures such as the Asphalt Solar Collectors (ASCs) can be constructed installing pipes or coils at the above-mentioned interfaces. Given this background, the present research was based on a Finite Element Analysis (FEA) and a related experimental activity to verify the suitability of including an ASC in the upper interface of a flexible pavement, 4 cm under the rolling surface. Shear strength FEA simulated an emergency heavy-truck braking to maximize stresses transmitted at the interface. Comparing the shear resistance at the interface with the FEA-simulated tangential stresses, it was found that the installation of the coils 4 cm under the road surface could threaten the structural integrity of the pavement. Thus, a 5 cm thickness for the overlay asphalt layer was suggested to avert possible design issues.