Paper by PLASSAIS GUILLOT from ISCR 10th 2006 Brussels Belgium
Photocatalytic materials are discussed for various applications in building technology ranging from de-soiling to de-polluting applications. However most of the efficiency proofs are derived from indirect laboratory scale tests. Italcementi Group has developed a range of cement-based products based on the TX Active? concept demonstrating both photocatalytic activity and performances (mechanical and chemical). Photocatalytic de-pollution efficiency has been assessed from laboratory to in situ tests as well as numerical simulations: (i) The laboratory tests allow a fast and controlled evaluation; (ii) In situ measurements allow a direct assessment; (iii) numerical simulations allow correlating the first two data and further predicting. In this paper are described two different laboratory test methods for which we propose a global way of interpreting the data. Moreover, examples of in situ measurements are given. In particular, a three month measurement campaign on the so-called Street Canyon Pilot (as part of the European project PICADA) has been performed: four lines of buildings were built at scale 1:5. The pollution level and meteorological conditions were measured for background and inside the street. It evidences a significant pollution reduction inside the street thanks to photocatalytic concrete. Other different in situ assessments on road applications (paving blocks and soundproof walls) have confirmed previous results.