Effectiveness of Chloride Salts on the Behaviour of Lime-Stabilised Organic Clay

In addition, the influence of 0.5% CaCl2 and 0.5% NaCl on the behaviour of lime-treated organic clay is investigated. Changes in soil's microstructure due to the addition of chloride salts were also examined by Scanning Electron Microscopy (SEM). 2. MATERIALS Artificial organic clay used in this study was prepared by mixing commercial kaolin with 0%, 0.5%, 1.5% and 3% commercial humic acid contents according to the dry mass of kaolin. The chemical elements present in each soil mixture are listed in Table 1. Table 1. Chemical elements in the tested soils. Element ABSTRACT: The presence of organic matter, in particular humic acid, is one of the most important factors affecting the effectiveness of lime stabilisation of clays. In this paper, an investigation on the effects of humic acid and chloride salts on the strength of lime-stabilised organic clay is presented. Different humic acid contents of 0.5%, 1.5% and 3.0% were mixed with kaolin prior to the stabilisation with 5%, 10% and 15% hydrated lime. The strength of the lime-treated organic clay was analysed using the Unconfined Compression Strength (UCS) tests at different curing periods of 7, 28 and 90 days and further verified by microstructure analysis. The results showed that a significant strength loss was obtained beyond 1.5% humic acid content and the strength was diminished at longer curing periods. However, by adding 0.5% chloride salts, the behaviour of lime-treated specimens with 1.5% humic acid content was successfully improved.