Avaliação de impactos ambientais gerados por estruturas de concreto armado na cidade de Chapecó-SC

Abstract

Reinforced concrete is the most used structural system in Brazil and worldwide. Its production requires huge amounts of raw material, water and energy. In addition, there is considerable emission of carbon dioxide (CO2) from the extraction of cement to the final destination. The high use of reinforced concrete structures is due to the ease of execution, the willingness to mold the most different shapes, as well as the low cost in relation to other structural systems. The factors that generate the environmental impacts on reinforced concrete structures are diverse, including the production/processing of cement and steel, the transport of raw materials and already industrialized concrete, so it is assumed that to make the More sustainable reinforced concrete structure, one of the means of reducing emissions, is the reduction of the volume of concrete used in the structure through the analysis of the structural design and the optimization of the structure. In the present study, CO2 emissions from reinforced concrete with a characteristic compressive strength of 20 MPa and 35 MPa are evaluated for the region of Chapecó – SC. The calculated parameters were based on extraction, production and processing data obtained from raw material supply companies and with the concrete producer selected for the research, and also calculated using the SimaPro Software 9.2.0.1, with its database adjusted for the region under study. Subsequently, in possession of the CO2 emissions data, the optimized design of structural elements (columns and beams) was carried out with the objective of minimizing environmental impacts, noting that, for concretes with higher compressive strengths, there is greater CO2 emission. Then, the carbonation of the structural elements (columns and beams) was calculated using the methodology described by Felix and Possan (2018) and its influence over the life cycle of reinforced concrete structures was evaluated. The results indicate that concretes with lower compressive strength have better CO2 absorption rates. Finally, the results obtained were compared to the literature, showing that factors such as local conditions can influence environmental impacts.