## 1 Introduction  
Expansive soils are clays that contain a large amount of expanding minerals and are prone to swelling and contracting in response to changes in moisture content. This can cause significant problems and damage such as the cracking of walls and settling of foundations. Calcium chloride is a salt known for attracting moisture when mixed with wet soil. Removing moisture from expansive clay material can increase strength and improve stability. The addition of cement to the soil, either in the form of Portland cement or another type of hydraulic cement, can further improve the stability of the soil. The cement reacts with the soil particles to form a stable matrix that helps to bind the soil particles together and increases the strength of the soil. The chemical stabilization of expansive soil is related to an added material that can react with the soil in the presence of water. This reaction can improve the swelling and shrinking characteristics as well as the soil's physical and mechanical properties. Researchers and practicing engineers are well aware that lime and cement are predominantly used for chemical stabilization. However, the amount of additives and the level of stabilization are dependent on the mineralogy of the expansive soil, in addition to other various placement conditions. The cost and the processes of mixing constitute a major issue in chemical stabilization methods. The advantages and disadvantages of using a particular stabilizer must be determined and evaluated by an experienced geotechnical engineer. Currently, lime is typically used as a common stabilizer as it costs less than other strong binders such as cement. Vast areas in the Kingdom of Saudi Arabia are affected by expansive soils. Expansive soils are reported in the east, north, northwest, and central areas of the country. The threats and damage caused by this type of soil to structures and foundations include uplift, twist, cracking, overturning, and collapse. The use of chemical stabilization can improve subgrade soils that support major roads and highways in the northern and north-western parts of the country. Extensive research was conducted on the use of chemical stabilizers for expansive soils. Studies reporting the use of lime have been published since the middle of the 20 th Century. [PERSON] [1] surveyed the soil stabilization process using lime, lime-fly-ash, and other lime-reactive minerals. Lime enhances the geotechnical properties of the stabilized soil by reducing its moisture content and plasticity index. The formation of flocculated soil particles takes place due to hydration and cation exchange capacity. [PERSON] [2] stated that adding quick lime to wet soil reduces its moisture content by nearly one-third. [PERSON] et al. [3] found that adding lime improves the strength and compaction characteristics rapidly in the early stages of curing and continues to improve at a slow rate in longer curing periods. [PERSON] et al. [4] investigated the addition of 3% and 9% lime to marine sediments and found that the plasticity index is reduced and unconfined compressive strength is increased. [PERSON] and [PERSON] (2022) [5] conducted a review on expansive soil stabilization using chemical additives. They also observed that the stabilization process occurs as a result of hydration and cation exchange. Pozzolanic reactions can cause soils to flocculate and form stiff lumps and particles. The minimum lime content required to maintain high pH value (pH = 12.40) in the soil-limic mixture is recommended as the percentage represented the optimum lime content ([PERSON] and [PERSON], 1966) [6]. The amount of lime required to achieve significant improvement varies from 5% to 10% according to the US Army Corps of Engineers, 1994 [7]. Other research studies [8; 9; 10; 11; 12; 13; 14; 15; 16] reported that the addition of CaCl\({}_{2}\) can increase the initial and long-term strength of constructed roadbed materials and improve their durability due to cation exchange and flocculation of soil particles.