Surface Dressing Treatment for Applications on Solar Roads

The solar road concept is a pavement system able to harvest energy from the solar radiation. This paper is part of a wide project for the design of a multilayer system able to harvest energy through the road. In this technology, the top layer plays a fundamental role because it has to support the traffic load, guarantee the vehicle friction and protect the solar cells. For this purpose, the authors proposed a novel approach for the construction of a semi-transparent layer made of glass aggregates bonded together through a transparent polyurethane, inspired from surface dressings. The procedure consists on spreading a first layer of polyurethane binder on the solar cells in order to obtain a uniform surface. Once the polymerization is completed, a second layer of binder is laid down and the aggregates are spread and compacted immediately. For the samples manufacturing, three different thermosetting polyurethanes and a 2/4 mm fraction of glass aggregates were used. The samples were compared in terms of optical and mechanical performances. The authors studied also the packing density of the aggregates in order to quantify the optimum amount of binder. The results show the potential of this novel top layer in terms of optical and mechanical performances, demonstrating the feasibility of the surface dressing treatment for applications in full scale solar roads.