Soil stabilization method has been around for quite a while in construction history. In soil stabilization, the soil is altered chemically or mechanically to lock it from moving.
Often when people think of soil stabilization, what comes to mind is erosion control. In construction, expansive soil stabilization methods seek to strengthen the soil beneath so that the building above remains stable despite the moisture exposed to it.
Soil Stabilization with Different Materials
One method cannot always solve all the problems one may have with their soil. Compaction and other expansive soil stabilization methods work by changing the physical or chemical composition of the soil.
- Soil stabilization using cement
Cement remains as one of the primary ways of binding soil. The soil stabilized with cement is commonly known as soil cement. The resultant cementing action is a reaction of cement, and siliceous soil in a reaction referred to as hydration reaction.
The following factors affect the soil-cement reaction:
- components of the soil
- the mixing process
- the compacting process
Some of the additives added to cement for soil stabilization are: lime, sodium carbonate, sodium sulphate, calcium chloride, and fly ash.
Advantages of using cement for soil stabilization
- Cement is readily available
- Its can be applied to a wide range of materials
- It’s considered to have advanced composition and properties
- It’s relatively affordable depending on the proximity to the manufacturer and the distribution network
- Soil Stabilization with Lime
Soil stabilization with lime is very effective for short-term modification of construction soil properties. Lime can modify almost every soil type and texture, including the finest-grained soil. It’s also effective in stabilizing clay soils with high plasticity levels.
Wet soil at construction sites is stabilized and dried using quicklime. Soil stabilized using lime reduces downtime and significantly improves the working surface. Lime works by changing the nature and composition of adsorbed layers and providing pozzolanic action. Soils with high plastic levels can be reduced by treating it with lime.
Advantages of using lime for soil stabilization:
- enhances its workability
- Increases soil stability
- Improves permeability
- Enhances the load-bearing capacity of road bases and sub-grade
- Soil stabilization with Bitumen
The bituminous materials used for soil stabilization are tar and asphalt. This kind of soil is mostly used in pavement construction. When bituminous material is added to the soil, it reduces its tendency to absorb water and impacts cohesion.
These two actions and the nature of the soil allow bitumen stabilization to be classified into four categories. These are
- Oiled earth
- Sand-bitumen stabilization
- Water-proofed mechanization
- Soil-bitumen stabilization
- Chemical Stabilization of Soils
Calcium chloride is both delinquent and hygroscopic. This quality allows it to be used as a water retentive additive in surfacing and mechanical stabilization of soils.
When the calcium chloride vapor pressure is lowered, it reduces the surface tension, decreasing evaporation rate. Calcium chloride facilitates compaction by acting as a soil flocculent.
It may also be necessary to repeat the calcium chloride to make up for the loss of essential chemicals through leaching.