Mechanical response of hydronic asphalt pavement under temperature–vehicle coupled load: A finite element simulation and accelerated pavement testing study

Abstract

Hydronic asphalt pavement (HAP) is an environmentally friendly functional pavement. It has an energy-harvesting function and can emit energy to melt snow in winter. However, the mechanical response characteristics, especially under vehicle-temperature coupled load, and long-term performance of HAP systems remain under-investigated. Motivated by this absence of research, the mechanical response of HAP under vehicle–temperature coupled loading was analyzed using the finite element method. Results indicated that concrete between adjacent pipes bears large tensile stress. Mechanical damage, therefore, is likely to occur in those areas. The effects of parameters, like pipe spacing, embedded depth, inlet fluid temperature, and air temperature, on mechanical response were also studied to determine a more optimized pavement structure. The study conclusions can provide a theoretical basis for universal application and standardized design method of HAP. Furthermore, in-situ testing sections of the aforementioned optimized HAP structure were constructed and their rutting performance was evaluated using the one-third-scale model mobile load simulator (MMLS3) to verify whether its long-term performance can meet the requirements for road durability. Results indicated that the average rutting depth of the HAP structure after 400,000 consecutive loadings was less than 1 mm, which is significantly less than that of the control section without pipes. The pipes in HAP not only enable the conventional pavement to harvest energy and melt snow but also can enhance the rutting resistance performance of the pavement to a certain extent.