Estudo de caracterização e viabilidade técnica de reaproveitamento do resíduo da pedra castelo do Piauí

Abstract

The ornamental stone industry plays a significant economic role in Brazil; however, it generates large volumes of waste during extraction and processing stages, which may cause considerable environmental impacts when improperly disposed of. In this context, this study aimed to evaluate the potential use of Castelo do Piauí Stone Waste (RPCP) as an alternative material for applications in the construction industry. The waste was collected in the municipality of Castelo do Piauí and subjected to particle size distribution analysis, Atterberg limits, and Standard Proctor compaction tests, as well as chemical and mineralogical analyses by X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA). The results indicated a predominance of fine particles, with diameters smaller than 0.149 mm, allowing the material to be classified as a low-plasticity silt (ML) according to the Unified Soil Classification System (USCS). This classification is adopted as an analogy for mechanical behavior, indicating low cohesion and suitability for use as a mineral filler. The chemical composition revealed a predominantly siliceous material, with relevant contents of SiO₂, Al₂O₃, and Fe₂O₃ and low CaO content, indicating largely inert behavior and high thermal stability. It is concluded that the RPCP presents physical, chemical, and mineralogical characteristics compatible with its use as a filler in construction materials. However, this research is limited to the characterization stage, and further studies involving mechanical performance tests and alkali–aggregate reactivity assessments are required to validate its application in structural concrete and mortar.