Improvement for the strength of salt-rich soft soil reinforced by cement

The corrosive ions in salt-rich soft soil have negative effects on soil-cement when the soft soil ground is reinforced by cement. To improve the strength of salt-rich soil-cement, a series of laboratory tests on metakaolin were performed, and the effects of metakaolin content and different ions on the mechanical characteristic of salt-rich soil-cement were explored as well. It was found that the strength of salt-rich soil-cement increased with an increase in metakaolin content, and then no further increase in strength was found when the metakaolin content exceeds a certain value. Therefore, salt-rich soil-cements with different ions have its optimal metakaolin content. Orthogonal test results show that three ions Cl, Mg2+, and SO42- have different effects on the strength of salt-rich soil-cement improved by metakaolin, Cl has the most important influence on the strength but SO42- is minor. Metakaolin has the characteristics of accelerating hydration reaction of salt-rich soil-cement, filling effect, and volcanic ash effect, which can reduce the negative effects of corrosive ions on the strength of salt-rich soil-cement.