Behavior of cement-stabilized marine clay and pure clay minerals exposed to high salinity grout

Soil-cement columns created by the injection of grout into the soil are common in practice for stabilizing soft soil in coastal areas. The behavior of clay-cement under marine conditions, especially considering the effect of both the clay mineral type and water salinity, has been less considered. The current study investigated the effects of high salinity grout on the mechanical and the physical behavior of cement-stabilized marine clay at a range of cement contents and water-to-cement ratios. The performance of the cement-stabilized marine clay was compared with those of kaolinite as an inactive clay and bentonite as an active clay. The results showed that, when saline water was used in the soil-cement mixtures containing kaolinite or marine clay, there was no decrease in strength and the cement content had no effect on the results. For active bentonite at 5% and 10% cement contents, the curing time had a negative effect on the strength; over time, the strength of the mixtures decreased. In practice, there should be no concern about the use of saline water to create grout at cement contents greater that 15%. However, if the clayey soil contains active minerals, a cement content of less than 15% is not recommended.