The present work aims to study the utilizing of some industrial solid waste materials to improve the behavior of the problematic soils such as swelling soil and soft clay. The soil under study is taken from two regions; Sahl-Al Tinah in north Sinai and Toshka in southeastern of western desert. We have tried to use constant ratio of CKD equal to 20% mixed with small ratios of cement (6%, 9%, and 12%) with different percentages of soft clay and swelling soil. In this regard important techniques (XRD, SEM) were carried out to identify the mineralogy and microstructure changes before and after treatment. Geotechnical tests (e.g. Atterberg's limits, Compaction, Unconfined compressive strength (qu) and free swelling) were measured. The results showed that the dry density increases as the swelling soil ratios decrease and the soft clay ratios increase from (1.65 to1.74 gm/cm³), the optimum moisture content (2o.19%). Unconfined compressive strength were increases as the swelling soil decrease and the soft clay increase from (30 to156.3) kN/m² at 90 days curing time and 6% cement, and it increases from (89.9 to 257.6) kN/m² at 90 days curing time and 9% cement, and increase from (215.9 to 389.8) kN/m² at 90 days curing time and 12% cement. The values of plasticity properties slightly decrease with gradually increase of soft clay percent and gradually decrease of swelling clay percent in all mixtures, free swelling decreased from (50% to 20%). XRD and SEM analyses after treatment showed that all clay minerals are transformed to new cementitous compounds, such as (C-A-H, C-S-H, and C-A-S-H), which has a more complex crystalline structure, as curing time increase.