Long-term strength of soil-cement columns in coastal areas

The soil-cement column is a ground improvement technique formed by the deep mixing method. In coastal areas, the soil-cement columns can deteriorate due to the attack of sulfate present in sea water. After long periods of exposure, the strength of these columns may decrease significantly, ultimately resulting in failure in the worst case scenario. In this study, needle penetration tests, uniaxial compression tests and a thermogravimetric analysis were applied to determine the extent of the deterioration of soil-cement columns exposed to synthetic sea water. An analysis model was developed and calibrated using the experimental data to predict the change in the total strength of the soil-cement columns as a function of time. The results show that the deterioration rate increases when the diameter of the samples decreases. The model proposed has potential to be used to design more durable soil-cement columns in coastal environments.