Avaliação de aspectos e impactos ambientais ao longo do ciclo de vida de telhas de fibrocimento com e sem amianto

Abstract

The construction industry has passed through significant changes in Brazil and it is of big importance to emphasize the growing demand for the reuse of this sector’s wastes, which is encouraged mainly by the National Environment Council’s regulation of the resolution 307/2002 and by the federal law 12.305/2010, which establishes the National Policy of Solid Waste. Together with the concern about construction waste, there are additional challenges regarding waste classified as hazardous, specifically, in this research project, the use of wastes composed by asbestos. Although the consequences and disadvantages of asbestos’ use are known, there is considerable resistance of the sector in substituting its use. This research project is, then, inserted in this scenario, with the purpose of evaluating the life cycle of this type of waste by applying the technique of Life Cycle Assessment (LCA) of asbestos in the civil construction sector, specifically in roof sheets. In this evaluation, the atmospheric emissions that cause the greenhouse effect and acid rain and the emissions with human toxicity potential beyond resource consumption (water and energy) were determined, in all the stages of the life cycle. After, aiming to compare the best scenarios generated in the life cycle analysis, the Assessment of Aspects and Environmental Impacts (AAEI) technique was applied. This assessment of the LCA evaluation added the impact on the use of natural resources and the health risk due the carcinogen factors of the tiles’ constituent material. Six scenarios of the fiber-cement tiles’ life cycle were evaluated, three of them containing asbestos and the other three containing polypropylene (alternative fiber). For all of them, the raw material extraction location, the location of the construction site in which the roof sheets would be used and the destination of the waste after its life cycle were determined, varying the location of production. As a final result, regarding the LCA and AAEI techniques, the best scenario with polypropilene had a better evaluation in four of the seven categories analyzed, in comparison to the best scenario with asbestos, which had better rates in the other three categories. When the transportation stages were not considered in the evaluation, the best scenario with asbestos generated fewer impacts in six of the seven categories than the one with polypropylene fiber (alternative fiber). Thus, with the knowledge that the transportation stages always will be part of life cycles, with both techniques considered, under the light of environmental evaluation, it is noticed that production scenarios of roofing tiles without asbestos show smaller generation of emissions, although with a higher resource consumption (water and energy). It is important to mention that, regarding the entire life cycle, the results have shown higher emission generation in the transportation stages; therefore, in adopting smaller transportation values, it would be possible to find more favorable scenarios.