Exploring the Effectiveness of TiO2 Treatments to Mitigate Alkali-Aggregate Reaction (AAR)

Several approaches have been developed to assess aggregates’ potential reactivity and the efficacy of preventive measures to mitigate alkali-aggregate reactions (AAR). Despite this, nanoparticles (NPs) of titanium dioxide (TiO2), highly effective mineral additives with hydrophilic/hydrophobic surface capabilities, have not been investigated in AAR mitigation. In this paper, an experimental program is presented to investigate the use of commercial TiO2 in both powder and colloidal suspension forms alongside two highly reactive aggregates. The powder will be incorporated as a filler (5%) into the mix, while the suspension will be applied as a protective coating to the concrete surface. To measure the effectiveness of TiO2 against AAR, part of the specimens will be subjected to artificial radiation to emulate photocatalysis conditions, while others were maintained under standardized AAR test environments. Finally, specimens will be assessed through compressive strength (CS), stiffness damage test (SDT), damage rating index (DRI), scanning electron microscopy (SEM), and porosity at different damage levels.