Adição de pó de brita em substituição parcial da argila caulinítica para produção de pavimento intertravado de adoquim cerâmico

Abstract

Adoquim is a rustic ceramic paving, of the interlocking type, with great economic and aesthetic potential, whose dimensions facilitate its installation and distribution of loads imposed by use, in addition to providing better thermal and acoustic comfort when compared to concrete or asphalt paving. This work aimed to study the influence of the addition of crushed stone powder in partial replacement of kaolinitic clay for the production of interlocking ceramic adoquim paving. The ceramic masses for obtaining adoquins were formulated from two starting materials: the mass of standard clay used in the production of ceramic floors by a ceramic industry, and crushed stone powder, originating from the process of crushing rock masses in a quarry, both companies located in the metropolitan region of Salvador-BA. After drying in an electric oven at 110 °C for 24 hours, the materials were characterized by X-ray fluorescence and by X-ray diffraction. The formulations of the test specimen masses were produced with 0%, 5%, 10%, 15 and 20% by weight of crushed stone powder in relation to the standard clay mass. The test specimens were shaped using a cylindrical steel die (30 mm in diameter and 60 mm in height), where 30 g of the formulated masses were added, under uniaxial pressing of 35 MPa for one minute. Sintering was performed in a programmable muffle furnace, at a firing level of 1.100 °C for 2 hours. Cooling occurred naturally within the kiln's combustion chamber until ambient temperature was reached. The sintered materials were characterized in terms of their physical properties regarding linear firing shrinkage, water absorption, compressive strength, and abrasion resistance, in addition to microstructural and thermal comfort analysis. The results of the characterized properties indicate that the addition of crushed stone powder is viable for the production of ceramic interlocking pavements for light traffic, since all formulations studied met the requirements for compressive strength, water absorption, and abrasion resistance of the foreign technical standards NTC 3829/2004 (Colômbia) and ASTM C902/2015 (United States). This study contributes to expanding the use of ceramic paving stones in Brazilian civil construction and enables the use of crushed stone powder as a productive input, reducing the consumption of natural raw materials in the ceramic industry.