Análise da resistência mecânica de um solo estabilizado com resíduo de rochas ornamentais.

Abstract

The accelerated growth of the ornamental stone market is responsible for waste generation in Brazil and worldwide, causing environmental impacts from the rock cutting stage to the improper disposal of this material in the environment. These impacts include decreased agricultural productivity, air pollution, public health linkage problems, among others. Thus, it is important to provide alternatives for recycling these wastes. In soil mechanics, expansive soils are of the type that need upgrading to have mechanical properties and deformability suitable for use in construction. Studies have been developed from the use of ornamental rock residue as a proposal for the stabilization of this type of soil, since the lime present in the residue, in contact with the soil, promotes pozzolanic and cementation reactions, which are responsible for give the soil improvements in resistance properties and expansion control. Therefore, the present research evaluated the use of ornamental rock residue as stabilizer and mechanical strength enhancer of an expansive soil. The study was also conducted with lime as an additive for the same soil in order to compare the performance of both stabilizers in relation to their stabilization reactions with the soil. For this, physical characterization of the soil, evaluation of the pozzolanic activity and chemical characterization of the residue were performed. The research was carried out with the manufacture of 27 specimens for each stabilizer in the apparent dry specific weights of 14, 15 and 16 KN / m³ varying the content of each additive. The contents of 4%, 6% and 8% of lime are added to the soil and the contents of 30%, 40% and 50% of ornamental rock residue to perform the uniaxial compressive strength test. During the research, it was possible to observe that the waste used did not present pozzolanic reactions capable of containing the soil expansion, thus, the curing process of the soil-residue specimens occurred without flooding. From the analysis of the test results it was noticed that lime reacts positively with the soil but the residue was practically inert. The mechanical strength analysis showed that the increase of lime content together with the increase of dry specific weight value increased the mechanical strength of the soil, confirmed by the reduction of porosity, which in turn allowed a better interaction between the soil. and lime. However, stabilization with the residue provided little increase in resistance when the additive content was added together with the increase of the dry specific soil weight value. The results allowed to conclude that the values of simple compressive strength of the soil with the residue were inferior compared to the soil with lime, being the growth curve almost constant for the residue and increasing for the lime. However, further study is required with a residue that contains larger amounts of marble, in order to provide pozzolanic reactions necessary to contain the expansion of the soil under study, with consequent improvement in the values of its mechanical resistance, thus providing a environmentally sound destination for these types of waste.