Influence of the addition of a byproduct of salt production (Carago) and curing time on the expansibility properties of an expansive soil in the city of Mossoró in the state of Rio Grande do Norte (RN)

Abstract

Expansive soils have as their main characteristic the volumetric variation due to the change in moisture content that results in damage to engineering works. The stabilization of these soils can be done with the addition of binders that reduce or eliminate the expansion. This research aimed to evaluate the influence of the addition of carago on the properties of expansibility and shear strength of an expansive soil in the city of Mossoró/RN. For this, tests of geotechnical characterization, compaction, free expansion, expansion stress and direct shear strength were carried out in soil mixtures with addition of 5% and 10% of carago. The samples with 10% carago showed a reduction in free expansion, with emphasis on the 25% reduction in the samples with 7 days of wet curing. An increase in the expansion stress occurred in all samples with carago subjected to dry curing, with the exception of the sample with 10% carago and without curing. Longer dry curing time increased free expansion and expansion stress in all samples.