## 3 Results and Discussion  
The swell potential is a direct measure of the effect of calcium chloride with cement on the behavior of naturally expansive clay, which is well demonstrated in Figures 1 and 2. A short curing period of 3 days was not sufficient to afford the required reduction in the swell potential of clay with calcium chloride contents of 4% and 6%. Notably, the curing period was crucial for the clay with the added 2% cement. An improvement in swell behavior due to the addition of calcium chloride with cement is expressed as a reduction in the swell potential. An 8% reduction is observed for clay with 4% calcium chloride and a 25% reduction is observed with 8% calcium chloride. Samples prepared and cured for 28 days were found to be not better than those cured for 7 days. Typically, a curing period of 7 days for concrete produces greater than 75% of the 28-day strength. Factors other than curing can cause such conditions, which include the non-uniform distribution of additives or non-identical placement conditions. Generally, for the addition of up to 8% of calcium chloride with cement, the higher the calcium chloride in the clay, the higher reduction in the swell potential. Increased suction is developed by the addition of calcium chloride, and suction is directly proportional to the percentage of the added calcium chloride (Figures 7 and 8). Generally, a high suction is associated with high swelling clays, but the increases in suction do not necessarily cause more swelling. This is due to the addition of cementing agents, which maintain strong particle-to-particle bonds [11]. The expansion will be arrested even at a high suction pressure. In some cases, a sulfate heave was reported to take place in clays rich in sulfate and sulfide (>3000 ppm) by the stabilization of clays using calcium-based additives [11; 37]. Figure 5: Variations of the compression index versus the percentage of CaCl\({}_{2}\) (2% cement added). Figure 6: The compression index of the clay treated with CaCl\({}_{2}\) (2% cement added) at different curing times. Stabilizers containing calcium can increase the pH, leading to the dissolution of clay minerals and the formation of Ettringite minerals as a result of the combination of sulfate minerals, water, and calcium. This mineral can swell more than two times its original volume. From the investigation of the compressive strength and the stress-strain behavior, the unconfined compressive strength is slightly reduced by the addition of a high content of calcium chloride. The loss of strength is expected because calcium chloride is a soluble salt and can slowly dissolve in water. As a result, voids can form within the soil mass, which can provide room for the soil to swell, and this phenomenon is reflected as an overall reduction in the heave. The slight reduction in strength is not a serious issue compared to swelling and expansion. With cement, only the strength of the clay was increased, and it reached its maximum at a curing period of 28 days, but with the addition of calcium chloride, the compressive strength was lower (Figures 9 and 10). The influence of 7- and 28-day curing periods on the stress versus axial strain is shown in Figures 11 and 12. Figure 8: The suction of the clay treated with CaCl\({}_{2}\) (2% cement added) at different curing times. Figure 7: The variation of suction versus the percentage of CaCl\({}_{2}\) (2% cement added). Figure 11: Stress versus axial strain at a curing period of 7 days. Figure 10: UCS of the clay treated with CaCl\({}_{2}\) and 2% cement at different curing times. Figure 9: Variations of UCS versus the percentage of CaCl\({}_{2}\) (2% cement added). The EDX chemical estimates for the points viewed by SEM indicated that the chloride content (computed as KCl) increases with the calcium chloride content. The other chemical compositions varied slightly. Table 4 summarizes the EDX results and the chemistry of clay at the points viewed.