Effect of Lime Stabilisation on the Strength and Microstructure of Clay

Lime stabilization is one of the techniques that can be used for improving the engineering properties, particularly the strength, of soft clays. This paper aims to investigate the effect of hydrated lime on the strength and microstructure of lime treated clays. In order to illustrate such effect, a series of laboratory tests were conducted. Atterberg limits, compaction tests, unconfined compressive strength tests and scanning electron microscope (SEM) were carried out on kaolin clay mixed with 5% hydrated lime. The results indicated that the addition of lime resulted in a reduction in the plasticity of kaolin and an improvement in compaction properties. The unconfined compressive strength (UCS) of stabilized clay experienced an increase with lime addition. Two variables influencing the amount of strength developed were studied. These variables included curing time and water content. Curing time contributed to an increase in the UCS, from 183 kPa to 390 kPa, that is approximately twice of the strength of untreated kaolin. SEM analysis showed the presence of the cementious products in the kaolin clay resulted from lime-clay reaction.