July 2012
·
558 Reads
·
7 Citations
Air pollution is a prominent critical issue of vehicles. The toxic pollutants are harmful to the environment, hazardous to human health and difficult to degrade by natural means. Therefore a significant amount of efforts have been done on road pavements that directly interact with vehicles. Basing on the synergetic effect of cement and titanium dioxide discovered in recent years new road pavements were developed. In particular, photocatalytic cementitious road materials can represent a key element to improve air quality, thanks to their ability to accelerate the natural reaction of oxidation. This paper deals with the development of several types of photocatalytic cementitious road pavements, such as paving blocks, asphalt concrete filled up with a photocatalytic slurry and concrete roads. Large laboratory and field-testing programs have been conducted measuring the environmental effectiveness by means of a specific set-up and in-situ sources, respectively. Functional and mechanical tests have also been performed on the materials studied to investigate their behavior under traffic loadings. Indeed, road pavements have to guarantee both de-polluting effects and performances usually required to a road pavement wearing course, according to the current Standards. The large research activity conducted till now clearly showed the significant contribution of such innovative materials to the improvement of air quality, reducing the nitrogen oxides concentration up to 60% in some local weather conditions. They can represent a new frontier of the research aimed at reducing air pollutants, for environmental friendly solutions. The findings underline the benefits of the inclusion of titanium dioxide in concrete pavements.