Stabilized soil is to serve under various local conditions, such as hot or cold weather, and dry or wet periods. The problems with non-treated soils are:
- deformations created under the loads of vehicles, machines, buildings, etc.
- shrinking and swelling due to higher or lower water saturation
- water permeability which leads to various forms of deformations, from small ones such as small cracks, to large ones such as erosion
Methods of soil stabilization
There are various methods for stabilization of soil and they can be broadly divided into physical and chemical ones. Physical methods involve physical processes to improve soil properties. This group comprises compaction methods and drainage. Drainage is a systematic removal of excessive water from soil by systems of pumps, pipes and canals with a goal to prevent soil from swelling due to saturation with water. Compaction processes lead to higher density of soil and thus less space for water to enter, i.e. compacted soil is more water resistant. Drainage is less common due to generally poor correlation between method effectiveness and cost. Compaction is very common method. Although it makes soil more resistant to water, this resistance will be decreasing over time and deformations of roads, buildings and other infrastructure that are to serve for decades will eventually occur. Physical methods of stabilization of soil are energy, machinery and equipment demanding.
Chemical stabilization
What need to be changed are chemical properties of soil, so that it becomes irresistible to water influence and hard enough to bear projected loads. Chemical soil stabilization techniques use chemicals and emulsions as compaction aids, water repellents and binders. The most effective chemical stabilization is the one which results in non-water-soluble and hard soil matrix. Binders connect soil particles together, making the soil body one unity. If the resulting matrix is not easily affected by water and other influences, long-term stabilization of soil is achieved.
Commonly used chemical binders
Commonly utilized binders are quicklime, hydrated lime, Portland cement, fly ash and cement kiln dust (CKD). The choice between these binders depends primarily on the type of soil and local regulations on environment protection. Portland cement is not suitable for soils with significant content of organic substances and for areas with seasonal frost heave. Lime is not good stabilizer for silts, granular materials and soils with sulphate contents higher than 0.3 percent. Conventional chemical stabilizers should not be used for treatment of for surface layers as they cannot resist abrasive action of traffic and machinery movements. Traditional chemical processes of stabilization of soil are very time dependant and can continue over a long period of time.
Lime is produced from limestone through a very energy demanding process and with high carbon dioxide emission. If the treated material is not protected from runoff, some lime could be washed into the surrounding environment and have an impact by raising the pH. Fly ash can damage vegetation adjacent to the treated terrain. As it contains heavy metals and other compounds, this stabilizer is potentially harmful to environment. Cement kiln dust must be applied properly to prevent environmental contamination. The toxicity of CKD must be determined for every case separately. The finer particles have higher concentration of sulphates and alkalis, while coarser particles contain higher concentration of free lime. The studies have shown that applications of fly ash and CKD in stabilization of soil have caused and may continue to cause, contamination of nearby soils, surface water and ground water.
Alternative Solution
Advanced solutions of stabilization of soil, considering the cost effectiveness, quality, longevity, applicability and environmental influence, are provided by Global Road Technology (GRT).
Application Procedures
Construction procedures are simplified with GRT’s products for stabilization of soil. GRT agents can be mixed with salt or fresh water and applied using only a water truck, grader and roller, where sophisticated stabilising machines are not available. Applications of GRT products are extremely quick and treated terrains are operational within a few hours of GRT’s products being applied. Unique engineering properties enable a 70% reduction in overall pavement depth compared to untreated ground.
Durability
Extensive laboratory analysis followed up with field-tests in the world’s harshest conditions ensured that GRT roads survive through extreme temperatures and severe weather events. GRT roads require less maintenance which saves on machinery purchase, hire and maintenance, as well as overall running costs such as fuel and tyres. For maintenance activities such as fixing potholes, all that’s required is a shovel, wheelbarrow, and polymer product. GRT offers products suitable for surfacing whereas strong, flat and non-dusty surfaces are provided.
Influence on environment
All GRT products, including those for stabilization of soil, are extensively tested by Environmental Resource Management (ERM), a leading international third party environmental testing laboratory, and certified environmentally friendly. Every component of every product used at GRT is certified non-toxic to people and the environment, and everything involved with their processes has a very small carbon footprint.
For more information regarding Global Road Technology or stabilization of soil please contact: https://globalroadtechnology.com/contact-grt/
