Correção granulométrica do solo de Dourados-MS com areia para fabricação de tijolos de solo-cimento com adição de resíduos

Abstract

Soil-cement brick is also known as ecological brick, it receives this designation due to its manufacturing process does not involve burning, which is present in conventional brick manufacturing processes, another important aspect is that soil-cement brick can be produced in the own construction site using local soil, as long as the soil is suitable for this purpose. Several locations do not have soil that meets the requirements described in NBR 10833:2012 for the manufacture of soil-cement bricks, such as the soil in Dourados-MS, which, in order to be used for the manufacture of soil-cement bricks, requires a granulometric correction is carried out. In several studies, the incorporation of waste into the mix for the manufacture of soil-cement bricks has been studied, aiming at the reuse and/or recycling of materials that are considered waste in civil construction or other production processes. Therefore, the objective of this work was to perform the granulometric correction of the soil in Dourados-MS using construction sand for the manufacture of soil-cement bricks and to evaluate the effects of adding rubber fibers from gypsum waste, coming from scrap tires and construction, respectively. The soil used to manufacture the soil-cement bricks was collected at Unit II of UFGD, Dourados-MS. Due to the collected soil not having adequate grain size for the manufacture of soil-cement bricks, the grain size correction was carried out by mixing 50% local soil with 50% sand used in civil construction. The mix used to manufacture the soil-cement bricks was 1:8 (cement: mixture of soil and sand), in volume, this was considered the reference mix for the manufacture of soil cement bricks. Rubber residues were added to the reference mixture in proportions of 2.5; 5.0 and 7.5%, in relation to the cement mass of the mix, and mixes were also prepared with the addition of 5.0 and 10.0% of gypsum in relation to the cement mass. Fifteen specimens of each treatment were molded in a manual press, being the reference treatment (without addition of waste), the treatments with addition of crushed rubber (reference trace plus additions of crushed rubber) and with addition of gypsum (reference trace plus plaster additions). After 28 days of molding and curing, the specimens were subjected to compression resistance and water absorption tests, according to procedures described in NBR 8491: 2012. The mixture of 50% soil with 50% sand was adequate to correct the granulometry of the local soil for the manufacture of soil-cement bricks. The test specimens, without the addition of residues, presented compressive strength and water absorption of 0.66MPa and 20.67%, respectively, values considered not suitable for soil-cement bricks, according to the limits established by NBR 8492:2012. The addition of rubber and gypsum residues did not increase the compressive strength and water absorption values.