Environmental interactions and physical resistance of a fine waste deposit from dimension stone industry

ABSTRACT Although several works propose applications for the fine wastes generated by the dimension stones processing, the financial advantages of recovering these materials are not yet evident. Then, the description of the deposits, much of them constructed without screening or any environmental protection measure, becomes indispensable for their best management. This work studies the physical, chemical and mineralogical characterization, as well as the mechanical resistance of a traditional waste deposit and its geological substrate. Around 76% of the particles that compound the wastes are smaller than 0,0625 mm and their humidity vary between 26 and 60%. The pH-values are between 8.2 and 10.5. The major chemical elements are Si, Al, Fe, and, at less proportions, Ca, Na, and K. These elements compound quartz, plagioclase, microcline, calcite, muscovite, biotite, and zircon. When comparing the characteristics of the wastes with the geological substrate, indicatives of the analyzed substances’ migration was not found. The Standard Penetration Tests (SPT) show that the layer´s strength is not good enough to receive shallow foundations. It is probable that Fe concentrations at some levels contribute for incrementing the deposit´s mechanical resistance.