A Double Layered Photocatalytic Concrete Pavement: A Durable Application with Air-purifying Properties

Photocatalytic concrete constitutes a promising technique to reduce a number of air contaminants such as NOx and VOC’s, especially at sites with a high level of pollution: highly trafficked canyon streets, road tunnels, urban environment, etc. The use of a double layered concrete (or two lift concrete) provides a durable solution by allowing the insertion of photoactive TiO2 in the top layer of the concrete pavement and recycled concrete aggregates in the bottom layer, without jeopardizing the durability of the pavement. In contact with light, the TiO2 is activated and able to reduce different pollutants in the air. A double layered concrete with photocatalytic materials in the top layer has been constructed in March 2011. This was done in the framework of a broader environmental sustainability project ECO2PROFIT, which deals with reduction of the emission of greenhouse gasses and sustainable production of energy on industrial estates in the frontier area between Flanders and Holland. This paper focuses on the construction of the double layered concrete in Wijnegem and on the influence of different parameters on the photocatalytic efficiency of the pavement.