This study investigated the progression of deterioration in cement treated surplus soils with cement contents of 1.7, 3.5 and 5.3 % under soaked condition by conducting needle penetration test and measuring calcium ion distribution within soil specimens. It was found that deterioration has progressed throughout the specimen after 336 days soaking in all the cases. From the measurement of calcium ion distribution, it was identified that calcium has leached out from the centre to the surface of the specimens though that distribution did not follow a good correlation with localized strength distribution. It was understood that the progression of deterioration of improved surplus soils with lower cement contents cannot be explained only with the remaining amount of calcium. |