From analysis to decision: Revision of a multifactorial model for the in situ assessment of NOx abatement effectiveness of photocatalytic pavements

The analysis of NO x abatement of photocatalytic construction materials under outdoor exposure still presents important challenges. Statistical models are a necessary tool to account for the large uncertainties involved in such complex, multifactorial processes, especially if employed in the context of decision problems confronting local authorities and other stakeholders in everyday practice. On this background, the paper reports on the revision of a preliminary multiple linear regression model for the comparative study of NO x removal behavior of urban pavement materials. The model is based on in-situ measurements at pilot plant scale, performed on nine different of such materials. Important advances of the model development include the significant enhancement of its statistical robustness and application boundaries regarding environmental exposure conditions or the materials analysed. The model identifies the material substrate humidity as a key variable and reveals the importance of Ti coating quality. Microscopic characterizations lean support to the model predictions.