INFLUÊNCIA DO TEOR DE UMIDADE NA ABSORTÂNCIA DE PAVIMENTOS INTERTRAVADOS DE CONCRETO

Abstract

Paved surfaces have been one of the causes of cities microclimate change and the urban heat islands (ICU) formation. Therefore, the understanding of cooling mechanisms and the study of thermal properties of cold pavements are important factors in the ICU mitigation study. So, this paper aims to present the variations of the spectral reflectance and solar reflectance in function of the colour and moisture content of three concrete pavements. For the execution of this study, a portable Alta II spectrometer was used, following the normative recommendations of ASTM C1549-16. The method was applied to obtain the solar reflectance of three interlocking concrete pavements samples in the dry and saturated state. The results show that the gray pavement in dry state increases in average 13%, when compared to the solar reflectance in the saturated condition; and the red pavement suffers a variation of approximately 4% between the same states. This fact is justified by the change in coloration when the sample is saturated. The gray sample between the dry and saturated condition is the surface that presents the highest variation of the hue, which would increase its absortance. In addition, it is worth mentioning that the gray pavement has higher reflectance than the red pavement in the dry state. However, in the saturated condition the spectral reflectance in the infrared range of the red pavement is superior to the gray colored pavement. Finally, this work contributes to the refinement of the albedo values, which is one of the properties that make the cold pavement a mitigation strategy for ICUs.