Evaluation of the Alterability of Natural and Artificial Agglomerated Stones Produced in Epoxy Matrix

The growing demand for sustainable solutions in civil construction has driven the use of industrial waste in the formulation of new materials. This study evaluated the alterability of artificial stone slabs produced with 87% ornamental stone waste (Dumont Quartzite and Preto São Gabriel Granite) and 13% epoxy matrix, using the vacuum vibro-thermo-compression technique. Alterability was tested against staining agents, chemical attack, wetting and drying cycles, UV radiation, salt crystallization, three-point flexural strength test after freeze–thaw cycles, and natural weathering. Quantitative results revealed high physical stability, with mass loss varying only between 0.11% and 0.23% in wetting and drying cycles. In salt crystallization, mass loss ranged from 0.38% to 0.47%, lower than the rates of 0.87% and 1.36% reported in the literature for similar materials. Regarding mechanical performance, freeze–thaw cycles caused reductions in flexural strength between 11.66% and 31.59%; however, the stones maintained final strength values above 20 MPa, classifying them as very high-strength materials. The results indicated good physical and chemical stability of the materials, with low mass loss and preservation of mechanical properties, except under UV radiation and natural weathering, which caused significant chromatic alterations. The data obtained demonstrate the viability of applying these stones in indoor environments, promoting the valorization of waste and contributing to the circular economy.