THE THRESHOLD OF SALT CONTENTS ON STRENGTH OF CEMENT-MIXED CLAYS: A FINDING OF LABORATORY TESTS

Through the laboratory test of the effect of salt contents on the strength of cement-mixed non-organic clays,The threshold of 3.5% was obtained.When the salt content of the clay is lower than this value,the strength of cement-soil will be increased due to solute salts dcrystallization and expansion.Conversely,when the soil have a higher salt content than the threshold,the strength of cemented clays will be greatly reduced due to structural destruction of cemented clays by the excessive crystallization and expansion of the salt.In addition,the corrosion mechanism of sulfate,chloride and magnesium salt to cemented clays is also discussed.And finally,based on the mechanism of the effect of salt on the strength of the cement-mixed clays,the prevention measures are suggested in case of the destruction to the cemented-mixed clays under high salt content conditions.