Soil stabilization using lime precipitation technique

Abstract

Many relevant studies on lime stabilization have been done with regard to swell-shrink behaviour of expansive soils. Sequential lime mixing technique was also proven to be effective in limiting the swell shrink behaviour. But, strength and deformation are generally the most important parameters in assessing the effect of soil stabilization in pavement and other geotechnical practices. Therefore, the impact of these modification techniques has to be studied in terms of unconfined compressive strength of lime-treated soft clays. Such studies would definitely imbibe confidence in the practitioners to take up these advanced stabilization techniques which would in turn make our designs more robust and safer. In this regard, the current investigation is taken up to examine the efficiency of lime precipitation technique by sequential mixing of sodium hydroxide (NaOH) and calcium chloride (CaCl2). The lime precipitated in expansive soil is likely to change the basic properties by short term modification reaction and long term pozzolanic reactions between soil and lime. In expansive soils, Initial Consumption of Lime (ICL) was established based on the experiment proposed by Eades and Grimm. All the laboratory tests were done by maintaining these moisture and compaction conditions. Lime precipitation was employed on the mixes and its time dependent impact on physico-chemical behaviour of expansive soil and formation of various cementation products were studied. The study discusses the effect of these reactions on Particle size, Unconfined Compressive Strength (UCS) and California baring ratio (CBR). The soil-lime modification reactions had significant impact on the index properties and Particle size of the expansive soil. Due to strong short time modification reactions and long term pozzolanic reactions, a notable increase in the CBR and UCS values of the expansive soil was observed