ABSTRACT
The chemical stabilization is a technique used to improve regional soils on the use of pavements subbases and bases. However, dosing methodologies still used in practice are based on simple tests, and cannot predict and explain the mixtures mechanical behavior. This study aims to analyze the chemical stabilization of a lateritic gravel used in the base layer of a highway. To this end, studied the mixture used in the site (78% gravel, 20% of sand and 2% of cement), and the same gravel mixtures with 2, 4 and 6% cement and hydrated lime. Laboratory tests were performed to characterize the soil, compaction in the Intermediate Proctor energy, expansion, California Bearing Ratio, unconfined compression and dynamic triaxial mixtures molded in optimum compaction condition for three curing times (0, 7 and 28 days). The resilient moduli results were evaluated by numerical analysis using KENLAYER software. To complement the analysis of the resistance results, X-ray diffraction and scanning electron microscopy tests were carried out. The results show that for the studied soil, the chemical stabilization with lime contributed little to the increase of strength parameters, but the use of cement showed greater potential use. Differences on behavior observed in unconfined compression tests and dynamic triaxial were explained by changes that occur in the microstructure during the stabilization process. Finally, it was clear that the tropical soil stabilization process is complex, with over current mechanical tests, such as dynamic triaxial, and unconventional parameters for pavement soil analysis, such as water/cement ratio and porosity, should be analyzes incorporated in order to obtain more consistent results.
Keywords:
Laboratory tests; Soils stabilization; Soil-lime; Soil-cement; Asphalt pavement
