Improvements in the mechanical behavior of a silty soil treated with rice husk silica, lime, and polypropylene fiber

ABSTRACT Stabilized soils correspond to a change in their properties to improve mechanical and engineering performance. This research aims to improve a silty soil from Guabirotuba Formation with 5% lime and three different rice husk silica contents (5%, 10%, 15%) and reinforce these same mixtures with the 0.5% polypropylene fibre. Geotechnical and chemical characterization, unconfined compressive strength (UCS), and the split tensile strength (STS) tests were performed in four different cure times (0, 30, 60, and 90 days). The results showed that the stabilized samples UCS and STS tests at 90 days of cure presented a resistance nine times bigger than the pure soil and the polypropylene fibre made the samples become more ductile. Finally, by simulating a pavement design applying these improved mixtures on the subgrade layer, a thickness reduction on the base layer was observed, going from 444.5 mm with pure soil to 203.2 when the mixtures were applied.