For the first time, the sustainability and functionality of expansive concretes have been increased through the addition of a photocatalytic agent (PhAg). The inclusion of the PhAg mainly modifies the properties of the fresh concrete and the resulting expansion obtained in different curing conditions. PhAg particles act as nucleation sites that increase and accelerate the formation of the expansion hydrates with the subsequent enhancement in the expansion performance. In fact, some modifications in the chemical composition of the expansive hydrates formed is detected due to the inclusion of the PhAg. However, since expansive hydrates are expected to growth in the surface of the PhAg, the photocatalytic activity decreases.

The authors would like to thank the Spanish Ministry of Economy and Competitiveness for the financial support given to this research in BIA2013-49103-CR-1-R project and in BIA2015-64363-R project.

Peer reviewed