Ageing of pigmented concrete pavements and consequences on albedo

Abstract

Cool pavements can be considered strategic instruments in the microclimate control of the cities. Therefore, it is necessary to understand the thermal properties of this material and ways to potentiate the cooling mechanisms. In this context, the changing of the albedo of the paved surface through pigmentation is one of the alternatives. However, the solar reflectance or albedo of this type of pavement tend to change, caused by age or time of use. Therefore, this article aims to analyze the effect of ageing on the albedo of colored pavements. For this, the reflectance of three interlocking concrete pavements was measured, using the Alta II portable spectrometer and the normative recommendations of ASTM C1549-16. The assay was performed on fresh and aged samples for 5 years. The results showed a decrease in the reflectance of the light materials and an increase in the darker pavements, in the first three years. These values were also compared to estimates of ageing through mathematical correlations, which presented an average variation coefficient of 0.08 between the methods, which demonstrate that the equation is a valid proposal in the prediction of pavement albedo aged.