The use of photoluminescent concrete has recently emerged as an intelligent strategy for enhancing the visual safety of civil infrastructure. Nevertheless, maintaining their structural durability under service conditions remains a fundamental challenge. The present study was conducted with the aim of experimentally evaluating the durability, adhesion, and mechanical stability of surface photoluminescent coatings modified with a cementitious dry-shake hardener (CDSH) on concrete, when exposed to aggressive environmental agents. To this end, 75 specimens were prepared in the form of five mix designs with surface layers containing different volumetric replacement ratios of SrAl₂O₄ particles—0, 12.5, 25, 37.5, and 50%—and were subjected to abrasion testing, acid immersion, freeze–thaw cycling, and thermal shock. The results showed that increasing the SrAl₂O₄ content, although improving the surface luminance of specimen C-4 by up to 114%, led to a severe 85.4% reduction in tensile bond strength (Pull-Off) after 60 days of immersion in an acidic environment due to increased capillary porosity. Furthermore, under 300 freeze–thaw cycles, the bond strength of specimens containing SrAl₂O₄ particles decreased by up to 66% as a result of accumulated hydraulic stresses. In contrast, these particles acted as a partial thermal insulator under thermal shock, so that at 450 °C the loss of bond strength in specimen C-4 was approximately 10% lower than that of the control specimen. In addition, the abrasion resistance of the coatings decreased markedly with increasing SrAl₂O₄ content.

Description: SrAl₂O₄:Strontium aluminate, CDSH: Cementitious Dry-Shake Hardener