Laboratory investigation into thermal response of asphalt pavements as solar collector by application of small-scale slabs

This paper investigates the thermal response of asphalt pavements as solar collector by application of small-scale asphalt slabs. The copper tubes were embedded in the asphalt slabs for the purpose of water circulation and the thermal sensors were also embedded in different depths for temperature measurement during slab preparation. A laboratory irritation simulation test was performed to heat up the asphalt slabs. The thermal energy stored in the slabs was collected by circulating water. The effects of flow rate, the time for starting collection and the initial temperature distribution of the slabs on the process of heat collection were evaluated. The results show that the asphalt pavement can be cooled down by the solar collection and thus is good for reducing the effect of heat-island in a city, but the temperature gradients between the slabs’ surface and the pipe are noticeable. Furthermore, the efficiency of an asphalt collector can be above 33.3% and the increase of flow rate result in a limited decrease of the surface temperature of asphalt pavement. The steady state temperature distribution in specimens could be used to set the starting collection time.