Análise dos limites de Atterberg em intervalos granulométricos de um solo laterítico puro e aditivado com Cimento Portland

Abstract

Tropical soils have mineralogical peculiarities resulting from their formation that give them unique structural behaviors. They are divided into lateritic and saprolitic soils, and both have unique characteristics when compared to other soil occurrences. One of the characteristics of interest from these soils is the plasticity, measured by the Atterberg limits test. Such limits are widely used in geotechnics and, in determining the moisture values, it is observed that the soil changes from a physical state to the next (solid, semi-solid, plastic and liquid). A method capable of improving soil properties, such as plasticity, is stabilization with Portland cement. In addition to the plasticity-reducing effect, this additive also promotes a significant gain in strength. The objective of this study is to compare the Atterberg limits of a pure lateritic soil with others that are mixed with Portland cement percentages in different granulometric intervals. For this purpose, a lateritic soil and contents of 5% and 8% of Portland cement of high early strength were used, in relation to the total mass. The experimental program involved the tests of granulometric analysis, specific gravity of the grains, liquid limit and plastic limit of the pure soil. Liquid limit and Plastic limit tests were performed at different granulometric intervals, starting from the #40 sieve, in pure soil and soil-cement samples. The results obtained showed a tendency of increase in the Atterberg limits, as the grain size is reduced. A reduction in plasticity was observed with the addition of the additive, as long as conditions are promoted for sufficient hydration of the cement grains. In addition, for smaller grain sizes, greater must be the amount of additive to reduce plasticity.