Analysis of strength development in non-traditional liquid additive-stabilized laterite soil from macro- and micro-structural considerations

The stabilization of soils with additives is a chemically modified method that can be used to improve soils with weak engineering properties. It has been well established that the size, shape, and arrangement of soil particles will affect the treatment process of natural soil with stabilizers. Also, the degree of enhancement is dependent on the morphology of the new formed products that bond the soil particles together. In this paper, unconfined compressive strength (UCS) test was performed as an index of soil improvement on liquid-stabilized (TX-85) mix designs. The time-dependent change in shear properties and compressibility behavior of treated soil was also studied using standard direct shear and consolidation tests. To better understand the structure and surface morphology of treated particles, FESEM, N₂-BET and particle size distribution analysis were performed on soil-stabilizer matrix. From engineering point of view, the UCS results indicated that the degree of improvement for TX-85-stabilized laterite soil was approximately four times greater than the natural soil in a 7-day curing time period. Also, increased compressibility resistance of treated samples with curing time was evident. Based on the results, it was found that the stabilization process modifies the porous network of laterite soil. In addition, new white layers of reaction products were formed on the surface of clay particles.