Phosphorescent mortars for finishing sidewalk pavements: mechanical, microstructural and luminescent performance

Public lighting has a significant impact on electricity consumption and CO 2 emissions, driving the development of more sustainable urban solutions. In this context, the construction industry offers potential for the incorporation of innovative materials capable of mitigating these environmental impacts. Luminescent composites containing phosphorescent powder represent a promising alternative, as they are able to emit light for extended periods after excitation. This study investigated the incorporation of a phosphorescent powder based on europium- and dysprosium-doped strontium aluminate (SrAl 2 O 4 :Eu,Dy) into finishing mortars for sidewalk pavements, using a mix proportion of 1:3:0.72 (cement:sand:water) with addition levels of 15%, 25%, and 35%, compared to a reference mixture. A preliminary bibliometric survey revealed a limited number of studies on phosphorescent mortars, highlighting the scientific relevance of this research. The mortars were characterized in the fresh state by workability, density, entrained air content, water retention, rheological behavior, and calorimetric analysis. At 28 days, physical, mechanical, and durability properties were evaluated, including water absorption by immersion and capillarity, void index, flexural and compressive strength, abrasion resistance, and performance after accelerated aging. Chemical and microstructural characterization was performed using EDXRF, XRF, XRD, FTIR, SEM/EDS, BET, and X-ray microtomography. The results indicated that the mortar containing 25% phosphorescent powder presented the most balanced overall performance in terms of mechanical behavior, durability, and microstructural refinement, whereas the 35% content showed higher initial illuminance and greater luminous persistence, confirming the potential of these materials for urban paving applications.