Avaliação geotécnica do resíduo de pedra morisca com adição de 30% em solo de Crateús aplicada em sub-base rodoviária

Abstract

The extraction of stone blocks for the production of ornamental slabs generates large volumes of coarse waste, mainly due to the breakage of slabs that do not meet commercialization standards. These residues are commonly accumulated around quarries and stone-processing plants, causing environmental impacts and waste management problems. In this context, this study analyzes the geotechnical characterization and the feasibility of using waste from Pedra Morisca, also known as Pedra Castelo Amarela, originating from the municipality of Castelo do Piauí, with a focus on its application in road pavement sub-base layers. The research is justified by the high generation of waste from the ornamental stone industry and the need for sustainable alternatives for its reuse. Brazil stands out as one of the world’s largest producers of ornamental stones, which intensifies this issue. Samples of the waste and of the characteristic soil from the Crateús-CE region were collected and subjected to laboratory tests for physical, chemical, and mechanical characterization. The tests included particle size analysis, Atterberg limits, compaction, and California Bearing Ratio (CBR), in addition to XRF, FTIR, laser granulometry, and TGA analyses. The results indicated that the waste exhibits predominantly granular behavior, low plasticity, and an essentially inert mineral character. The addition of 30% waste to the soil reduced the plasticity index and sensitivity to moisture variation, as well as improved the resilient modulus under higher confinement levels. However, the CBR results showed a reduction in the bearing capacity of the mixture, failing to meet the normative requirements for sub-base layers, although it shows potential for other civil construction applications, which justifies its investigation in future research.