Avaliação de rochas metassedimentares para produção de agregado para construção civil

Abstract

In recent years, the extraction and processing sector of ornamental stones has grown exponentially in Brazil. This is mainly due to the emergence of new technologies in mining methods and the equipment used for block extraction. However, as this sector has grown, the volume of solid waste produced by quarries has also increased, consequently leading to greater environmental and visual impacts in the areas where this mining activity takes place. In response, techniques have been developed to reduce this waste, one of which is the production of crushed stone from ornamental rock waste. Thus, the aim of this research is to characterize the waste from Elegant Brown stone and enable its use as an aggregate in the construction industry. To achieve this, the material was initially sampled and then crushed in a laboratoryscale crusher for size reduction. Next, a macroscopic and microscopic analysis was carried out on the material, and finally, it was classified according to its particle size distribution and abrasion, in order to determine whether this waste can be used to produce crushed stone for civil construction. The aggregate was classified as crushed stone 2 (two), with a metamorphic texture composed approximately of quartz (64%), plagioclase (1%), and a matrix (20%) with opaque minerals (15%), and an abrasion loss in the Los Angeles test of 13.2%. Based on the obtained information, we concluded that the material can be used to produce crushed stone for civil construction, according to the abrasion loss it has undergone. Despite the positive result, further analyses, such as those outlined in ABNT NBR NM 53:2003, NBR 5739-2018, and NBR 15577-1, should be conducted to validate this aggregate for the market.