Which Is The Best Chemical To Stabilize Soil Before Construction?

What is chemical soil stabilization? What are the chemicals used to stabilize the soil? What are the advantages and disadvantages of using chlorides, fly ash, polymer, cement, and lime in the stabilization of soil?

Chemical soil stabilization.

The soil properties are modified using chemically active materials. In chemical soil stabilization, chemicals are added to the soil and they react with it, altering its structure. The space between the soil particles is sealed by the chemical hence no room for water penetration. The chemicals used to stabilize soil includes:

• Chlorides.

This is popular in the stabilization of soil in the paved road. Magnesium and calcium chloride are the most popular.

Method of application.

Chlorides can be applied in two ways.

1. Chloride is added to the topsoil, mixed in, and then compacted.
2. The topsoil is sprayed with chloride.

This method works by trapping moisture from the environment and locking it into the soil. The soil loosens up if the water is applied, therefore after rain or snowmelt, the surface has to be treated again.

Advantages.

1. Compatible with all types of soil.
2. It is cost-effective.
3. It is easy to access.
4. It has been around and popular for decades.

Disadvantages.

1. It requires constant reapplication after the surface gets wet.
2. Excess chloride in the environment causes detrimental effects on plants and wildlife.
3. It is not water-resistant.

• Polymers.

A polymer is added to the soil to improve its physical properties. The polymers hold the soil particles together. They are mostly used in unpaved surfaces like temporary pond lining, dirt roads, and paths. The main types of polymers used are biopolymers and synthetic.

• Synthetic polymers.

They are mineral-based. They have environmental concerns as some of them may be toxic or not eco-friendly.

• Biopolymers.

They result from biological processes. They are less strong but are more environmentally friendly.

Soil particles bond to the polymer molecules. A polymer is therefore compatible with all types of soil. The polymer’s molecule size affects its performance on any type of soil since the soil particle has to fit into the polymer molecule. Polymers don’t work well with fine soil types.

Advantages.

1. It is compatible with all types of soil.
2. It is impermeable.
3. Application is easy.

Disadvantages.

1. It has a short lifespan.
2. A lot of product is required during application.
3. Not all polymers are environmentally friendly.
4. Lime and cement.

Lime or cement is mixed into the soil to increase its strength. The characteristics of the soil determine the percentage of lime or cement used. They are both used as binders and more are mixed into the soil if the plasticity is higher. They are popularly used on paved roads. They increase the strength of the soil by binding soil particles together. The soil needs to be analyzed before any additive is added to ensure the proper amount is used.

Advantages.

1. It is permanent and lasts long.
2. It decreases the moisture content of the soil.
3. It is compatible with most types of soil.
4. It increases the strength of the soil.

Disadvantages.

1. Potential health risk since the powder is very fine.
2. Extensive soil testing is required before application.
3. It is expensive.
4. It is only used for paved roads.
5. Fly ash.

This is a by-product of coal in coal-fired power plants. It can be used to increase the strength of soil by acting as a bonding agent. They are mainly used to treat the sub-base of paved roads.

Advantages.

1. It is compatible with most types of soil.
2. It is more cost-effective compared to lime and cement.
3. It can be used with soil with high moisture content.
4. It is permanent and lasts long.

Disadvantages.

1. It requires intensive labor.
2. Its availability depends on coal-fired power plants.
3. It poses certain health concerns.

Conclusion.

Chemical soil stabilization is when you use chemically active materials to modify soil properties. These chemicals react with the soil changing its structure. They make the soil more resilient for construction by keeping it intact. Each chemical agent used to stabilize the soil has advantages and disadvantages discussed in this article. The soil should be extensively analyzed to determine the best chemical to use.