Rainwater retention by green roof with precast cementitious with EVA

Abstract

Flooding problems in urban streets, resulting from the combination of occurrence of heavy rains and excess sealing of urban spaces, have caused severe losses to Brazilian cities. The green roof with your rainwater retention capacity is an interesting alternative to reduce the discharges on urban drainage systems. In this article, we will analyze the rainwater retention potential, from an extensive modular green roof, proposed with precast cementitious with lightweight aggregates of Ethylene Vinyl Acetate (EVA), originated from footwear industry waste. For this, were compared results from monitoring the volumes of rainfall over the proposed green roof and conventional roofing, all installed on prototypes. Additionally, a simulation was performed to estimate the rainwater retention capacity in a hypothetical scenario, in which a small portion of the city's buildings covers were installed green roof proposed. The additional contribution to rainwater retention due to the presence of lightweight aggregates on the modules was confirmed. It has also been demonstrated that the rainwater retention capacity by green roof proposed may vary between 73.3% and 90.5%, as the soil is wet or dry, respectively. The retention volumes estimated in the city's simulation can be up to 4 million liters/day in dry conditions on the green roof. Indicating that this type of coverage is encouraged in buildings; there is the potential to mitigate flooding problems on city roads.