Expansive soil is found in many regions in Egypt, especially in the new desert cities including
New Sohag City (town in Upper Egypt). In this study, the soil samples were taken from the place
of the Faculty of Veterinary Medicine at New Sohag University from a depth of 5 meters and it’s
used in the experimental program. The physical and mechanical properties of the natural soil
were obtained. Then the soil was treated with chemical additives (Addicrete P and Addicrete
BV) 0.5%, 1% and 2% by dry weight of soil. After treatment of soil the properties of the samples
were investigated at different times. The natural soil properties were used as control points for
comparison purposes. The main results show that with increase of Addicrete P the Plastic limit
increases and liquid limit decreases, hence decreases plasticity index and it is revealed that a
change of expansive soil texture takes place when Addicrete P are mixed with expansive soil.
While Addicrete BV does not effect on the Atterberg limits or the soil texture. As the amount of
“Addicrete P or Addicrete BV” is increased, there are apparent reductions in optimum moisture
content, unconfined compressive strength, free swell, swelling potential and swelling pressure. A
corresponding increase in maximum dry density was noticed. The paper contains on the many
important test results and these results analyzed to establish optimum dosage levels for each of
the treated additives. Based on the results obtained, it can be concluded that the expansive soil
can be successfully improved by Addicrete P and Addicrete BV.