Qualidade de tijolos solo-cimento com a inclusão de resíduos vegetais e urbanos

Abstract

Soil-cement bricksare obtained by homogeneously mixing soil, cement and water in suitable proportions.After compaction and wet curing, it results in a product with characteristics of durability and mechanical strength. For soil stabilization, besides the use of cement, the best choice option should be influenced by economic viability, the purpose of the work, the characteristics of the materials and the properties of the soil. The addition of reinforcement materials to soil improved with cement will result in a more resistant and ductile composite material. The addition of particles in the composite influences its mechanical behavior. In this context, the objective of this study was to evaluate the addition of different percentages and types of plant and urban waste in the quality of soil-cement bricks. Eucalyptus, Pinus, tire and PET residues were evaluated in percentages of 1.5 and 3.0% in dry mass. Both the soil (retraction, compaction, consistency limits, particle size analysis and chemical analysis) and the particles (morphological, chemical and physical characterization) were characterized.For the construction of the bricks, the constituents were weighed and mixed in a planetary mixer, followed by water addition and homogenization. This mixture was transferred to an automatic press to acquire the shape of bricks and they were packed on a flat floor and subjected to wet and dry cycles for 7 days. Soil-cement-particle bricks were characterized for their properties of density, moisture, water absorption, immersion loss, compressive strength, determination of thermal insulation and durability. It is not recommended to include 3.0% reinforcement material in bricks produced with Eucalyptus, Pinus and tire. The inclusion of 1.5% of Eucalyptus and 1.5% and 3.0% of PET promoted a significant improvement of the compressive strength, meeting the minimum values stipulated by the marketing standard, even after the durability test. These treatments obtained water absorption and loss of mass by immersion similar to those obtained for the control treatment. Moreover,there was significant improvement regarding thermal insulation, being therefore indicated for the production of reinforced soil-cement bricks.