Linear shrinkage and the methylene blue spot test in the analysis of plasticity of granulometrically stabilized laterites

Abstract

For a soil to be granulometrically stable, it must present low plasticity and a granulometric composition that conforms with the limits regulated by standards. This article presents a study of the clay fraction activity and plasticity of three laterites from the Triângulo Mineiro region, aiming to use them in a granulometrically stabilized base. The experimental phase contained the determination of liquidity limit, plastic limit, sand equivalent and silica sesquioxide ratio, in addition to a Methylene Blue spot test, linear shrinkage, MCT classification and X-ray diffraction. The results show that the sand equivalent alone is not able to evaluate the content of impurities of the clay fraction; it needs to be performed along with the Methylene Blue spot test. Linear shrinkage proved to be an important indicator of plasticity, capable of measuring small values of plasticity. Finally, the MCT classification precisely indicated the lateritic behavior of the samples.

Keywords:
laterites; granular bases; methylene blue spot test; linear shrinkage