Análise do comportamento térmico de pavimentos de concreto poroso antes e após colmatação

Abstract

The accelerated and unplanned growth of cities has led to the sealing of soils and, consequently, aggravated problems such as the Urban Heat Island effect (UHI). In this context, porous concrete paving represents a sustainable alternative, as it controls rainwater runoff and has a high albedo, a property that quantifies the amount of light reflected by the surface. Clogging is a phenomenon that involves the obstruction of the pores of the porous concrete, which occurs due to the entry of sediments and leads to the loss of the useful path of the porous concrete flooring. Therefore, this study aims to analyze the effects of clogging on porous concrete pavements, focusing on thermal behavior, thermal conductivity and evaporative process. Initially, the influence of air temperature and relative humidity on the surface temperatures of porous concrete pavements in the clean state was analysed, in which a significant sensitivity to environmental conditions was observed, highlighting the importance of these factors. Comparing clean and clogged sidewalks, it was found that while clean sidewalks had slightly higher surface temperatures during sun exposure, clogged sidewalks cooled faster. Thermal conductivity analysis highlighted a discrepancy between floors in a clean and clogged state, highlighting the influence of clogging on the heat capacity of the material. The presence of sand as a sealing material reduced the void content, increasing thermal conductivity, which is directly related to heating and heat dissipation. In the evaporation test, the clogged plates showed a slightly higher evaporated mass than the clean plates, this increase in evaporated mass was attributed to the clogged sand's ability to retain water between its voids. Therefore, the results suggest that clogging brought better results than pavement in the clean state in terms of thermal and evaporative performance.