A review on reflective materials for cementitious composites

The urban heat island (UHI) effect significantly impacts urban environments, driving the need for innovative cooling strategies. Reflective cementitious composites, with their potential to reduce solar heat absorption, offer a promising approach to mitigating UHI effects. This review explores factors influencing the reflectance of cementitious composites, including aggregate types, supplementary cementitious materials (e.g., slag, fly ash), water-to-cement ratios, curing conditions, and environmental exposure. Additionally, the incorporation of reflective fillers such as TiO₂, CaCO₃, and waste glass, as well as advanced coatings using white pigments (e.g., TiO₂, ZnO) and colourful pigments (e.g., Cr, Fe, Co), is examined. Emerging technologies like thermochromic materials, fluorescent quantum dots, and retroreflective additives are evaluated for their potential to enhance reflectance and durability. The review highlights that combining advanced reflective materials with optimised cementitious designs can achieve significant temperature reductions, offering a sustainable solution to mitigate UHI effects and improve urban thermal comfort.