This research is conducted to study combined electrokinetic and chemical processes for improving marine sediment. A series of experiments are performed to study the effects of this approach. In the experimental study, the electrokinetic treatment is conducted on a marine sediment mixed with chemical admixtures, including sulphate resistant cement, quicklime and coal fly ash. The effectiveness of the combined treatment is evaluated in terms of the undrained shear strength and compressibility, along with soil characteristics such as the soil water content, Atterberg limits, carbonate content, and pore water chemistry. The application parameters such as the electric current density and temperature effect are also discussed.
Chemical stabilization using admixtures such as lime, cement, fly ash and their combinations has been applied in engineering practice to improve engineering properties of soft soils (Mitchell and Hooper, 1961; Mitchell, 1976; Bell, 1988). These admixtures are also suitable to improve soft marine clays of high water content, high compressibility, and low shear strength (Al-Amoudi, 1994; Indraratna et al., 1995; Mathew and Narasimna, 1997; Supakij et al., 2004; Ho and Chan, 2011). The influencing factors for chemical treatment include the soil type, curing period, temperature, mixing ratio, initial moisture content, method of compaction, and time elapsed between mixing and compaction, etc. The management of dredged sediments from harbors, waterways and land reclamation is often challenging because of the high water content, plasticity, void ratio, and compressibility, as well as the low permeability. It is of great importance to accelerate consolidation and to increase the shear strength of the dredged marine sediments in engineering practice. Many studies have been performed to evaluate the feasibility of chemical stabilization in the improvement of dredged marine sediments (Dermatas et al., 2003; Boutouil and Levacher, 2005; Liu et al., 2005; Kamali et al., 2008; Rekik and Boutouil, 2009).