Cement Stabilization of Soil
Cement stabilization of soil is done by mixing pulverized soil and Portland cement with water and compacting the mix to attain a strong material. The material obtained by mixing soil and cement is known as soil-cement. The soil cement becomes a hard and durable structural material as the cement hydrates and develops strength.
Cement stabilization is done while the compaction process is continuing. During the compaction process we use some amount of cement. Some void space can be found in soil particle. Cement is just like paw, so cement can fill the void space of soil easily. As a result, void ratio of soil may reduce. After this primary tasks, when we add water in the compaction the cement reacts with water and become hard. So unit weight of soil is also may increased. Because of the hardening of cement, shear strength and bearing capacity will be increased. Because of the stabilization, permeability of soil may decrease.
Factors Affecting Soil Cement Stabilization
During soil cement stabilization the following factors are affecting.
- Type of soil: Cement stabilization may be applied in fine or granular soil, however granular is preferable for cement stabilization.
- Quantity of cement: A large amount of cement is needed for cement stabilization.
- Quantity of water: Adequate water is needed for the stabilization.
- Mixing, compaction and curing: Adequate mixing, compaction and curing is needed for cement stabilization.
- Admixtures: Cement has some important admixtures itself which helps them to create a proper bond. These admixtures pay a vital role in case of reaction between cement and water.
Advantages of Cement Stabilization
- It is widely available.
- Cost is relatively low.
- It is highly durable.
- Soil cement is quite weather resistant and strong.
- Granular soils with sufficient fines are ideally suited for cement stabilization as it requires least amount of cement.
- Soil cement reduces the swelling characteristics of the soil.
- It is commonly used for stabilizing sandy and other low plasticity soils. Cement interacts with the silt and clay fractions and reduces their affinity for water.
Disadvantages of Cement Stabilization
- Cracks may form in soil cement.
- It is harmful for environment.
- It requires extra labor.
- The quantity of water must be sufficient for hydration of cement and making the mixture workable.