Strength measurement and textural characteristics of tropical residual soil stabilised with liquid polymer

• Role of polymer concentration, plasticity index and curing time on strength development.
• Unconfined compression strength and micro-structural analysis of unstabilised and stabilised soil.
• Interaction between alkaline polymer and residual laterite soil.
• Polymer–soil matrix reaction products acts as a cementation binder between soil particles.

The stabilisation of soils with additives is a chemical process that can be used to improve soils that contain weak engineering properties. The effects of non-traditional additives on the geotechnical properties of soils have been the focus of much investigation in recent years. It has been well established that the plasticity index and also the size, shape, and arrangement of soil particles will affect the treatment process of natural soils with additives. In this study, a commercial liquid polymer (SS299) was used to improve the strength of Malaysian residual soil. Unconfined compressive strength (UCS), field emission scanning electron microscopy (FESEM), N2-BET surface area, and particle size analysis tests were used to investigate the influence of SS299 and the plasticity index on the time-dependent compressive strength and textural characteristics of tropical residual soil. The UCS results showed that the addition of 6% (as the optimum amount) of the selected additive increased the compressive strength of laterite soil noticeably, after 7 days of curing period. In addition, the increased compressive strength of the treated samples with the curing time was evident. Based on the FESEM results, it was found that the stabilisation process modified the porous network of the laterite soil. Furthermore, new white layers of reaction products were formed on the surface of clay particles.