Avaliação da substituição parcial de matéria prima convencional por lama do beneficiamento de rochas ornamentais e lama de carbonato de cálcio em argamassas colantes

Abstract

Brazil is the fourth largest producer of ornamental stone and cellulose in the world. These sectors generate high amounts of waste, including sludge. Ornamental stone sludge (LBRO) is generated in the stone cutting and polishing processes. Lime mud (LCC) is generated in the kraft process for pulp and paper production. The general objective of this study is the production of adhesive-mortar with partial replacement of the fine aggregate by these sludges. The adopted methodology for this study involves three stages, namely: the chemical, physical and mineralogical characterization of the sludges, in addition to tests of the adhesive-mortar both in the fresh and in the hardened state. The replacement was made in the proportions of 5%w.t. and 10%w.t. (total weight) of the fine aggregate passing through the Mesh # 100 sieve, and the percentage of fine aggregate retained in this sieve has not been modified. Sludge characterization tests were carried out, namely, wet granulometry, dry granulometry, specific surface area, thermogravimetric decomposition, gas pycnometry, x-ray diffraction and x-ray fluorescence. Tests were carried out in the fresh state, namely, consistency index, sliding and calorimetry. Tests were carried out in the hardened state, namely, resistance to traction adhesion, open time and water absorption by capillarity. The results obtained indicate a reduction in the consistency index and sliding as the proportion of replacement increases, it was observed that the hydration behavior is not altered by the replacement. The proportions of 5% of both sludges, LBRO and LCC, showed lower tensile bond strengths and less water absorption by capillarity than the reference adhesive mortar. While the proportions of 10% showed greater resistance to adhesion to tensile and reduction of water absorption when comparing to the reference trace