Soil Stabilisation with Ground Granulated Blastfurnace Slag

s from selected papers [15] Soil Stabilisation using Lime-activated Ground Granulated Blastfurnace Slag Synopsis: Soil stabilisation with cement or lime, is a well established technique for use in highway or foundation construction. Extensive laboratory investigations and a full-scale trial have been carried out to evaluate the performance of ground granulated blastfurnace slag (ggbs) in combination with lime, for stabilising soils. This paper reports the results of laboratory tests for strength and swelling, and also describes the full-scale trial. The applicability of lime / ggbs combinations has been demonstrated. In addition laboratory tests have shown a previously undemonstrated advantage where the incorporation of ggbs combats the deleterious swelling which can occur when sulphate-containing soils are stabilised with cement or lime. [20] Mechanisms by which ggbs prevents sulfate attack of lime-stabilised kaolinite Abstract: This paper describes the mechanisms by which ggbs prevents sulfate-attack of lime-stabilised kaolinite. Microstructural and mineral phase analyses of compacted cylinders of lime-stabilised kaolinite with different percentages of lime replacement by ggbs have been carried out using scanning electron microscopy (SEM) and x-ray diffractometry (XRD). The cylinders were immersed in 4.2% Na2S04 solution and also in deionised water for various time periods. The exposure data showed that the effect of ggbs in preventing the formation of expansive ettringite in lime-stabilised kaolinite, which had been exposed to 4.2% Na2S04 solution was dramatic. The results also revealed three different growth mechanisms of ettringite in the lime-ggbs-kaolinite systems that were exposed to 4.2% Na2S04 solution. These are: wellformed randomly orientated rods of high aspect ratio growing in pores and cracks, short needles covering surfaces of existing particles, and 'flower-like' needles radiating from isolated points and scattered randomly through the sample. [19] Influence of ggbs on the sulphate resistance of lime-stabilised kaolinite (specimens immersed in sulfate solution, rather than sulfate in the clay) Abstract: This paper describes the influence of ground granulated blastfurnace slag (GGBS) on the durability of lime-stabilised kaolinite in 4.2% Na2S04 solution. Sulphate durability was assessed in the laboratory by means of linear expansion measurements, microstructure and mineral phase analysis of This paper describes the influence of ground granulated blastfurnace slag (GGBS) on the durability of lime-stabilised kaolinite in 4.2% Na2S04 solution. Sulphate durability was assessed in the laboratory by means of linear expansion measurements, microstructure and mineral phase analysis of compacted cylinders of the lime-stabilised kaolinite with different percentages of' lime replacement by GGBS. The cylinders were immersed in 4.2% Na2S04 solution and also in deionized water for various time periods. The exposure test data showed that the effect of GGBS on reducing expansion in 4.2% Na2S04 Solution is dramatic. The results also showed that high percentages of replacement of lime with slag (in particular 83%), with just enough lime to activate the slag, were the most effective in preventing sulphate solution attack. [11] Shear strength, permeability and porosity of Kimmeridge clay, stabilised with lime and ggbs ABSTRACT: Kimmeridge Clay, obtained from Blackbird Leys near Oxford, England, UK, was stabilised Kimmeridge Clay, obtained from Blackbird Leys near Oxford, England, UK, was stabilised with a total binder content of 8 % at various slag/lime ratios. The samples were cured for 12 weeks, 24 weeks and 1 year at 10, 20 and 30 'C. The shear strength development was assessed in a series of undrained, unconsolidated triaxial tests, during which the pore water pressure was measured. The permeability of the saturated soil-lime-ggbs mixes was measured in a computer controlled triaxial cell. The samples were then examined for their porosity and pore size distribution in order to assess the involved mechanisms. The results indicate that, in general, the shear strength increases with increasing slag/lime ratio, particularly when the soil is cured at elevated temperatures. Also permeability drops significantly with increasing slag/lime ratio and increasing curing period, whereas curing temperature has only a minor influence on permeability. The pore refinement is maximised at replacement ratios of between 4% slag