Undrained & drained behavior of lime-treated organic clay with calcium chloride (CaCl2)

Abstract

The effectiveness of lime as a chemical additive for the stabilisation of organic clay is considered uncertain, especially in the long term. Previously, it was shown that a high humic acid content (i.e. > 1.5%) reduces the strength of clay undergoing the process of lime stabilisation. The results of tests carried out on lime-treated specimens revealed that lime may not be the only available option to stabilise organic clay comprising more than 1.5% humic acid. A mixture of 1.5% humic acid, at 5% optimum lime content was prepared to be stabilised with various amount of calcium chlorides, CaCl2) (0.5%, 2.0% and 5.0%). The strength properties of specimens were examined by undrained (CU) and drained (CD) triaxial tests. Curing periods of 7 and 28 days were chosen to assess the influence of salts for improving the properties of lime-treated organic clay. Overall, there was significant improvement in the properties of the lime-treated organic clay when the chloride salt (i.e. CaCl2)) was introduced. Changes in the soils' properties were discovered early (i.e. after 7 days) in each specimens.