Soil stabilisation is carried out to change either the chemical or physical properties of a natural soil in order to alter its strength and consistency. This process is done to meet the requirements as set out by the laboratory for a particular project. The ultimate objective is to stop water penetration which softens the base and results in faster deterioration.
Historically, changing the ground in preparation to support structures for construction goes back as far back as Roman times. There are even cases where the work was done so well that their systems and roads are still in use today.
The methods that the world is familiar with, however, only began to be used in the 1960’s and 1970’s, when engineers had to review the way poor soils were changed on building sites, in the face of a shortage in aggregates and fuel resources. Modern technology has developed a lot to assist in improving the methods and additive usage to suit specific needs and applications.
How does Soil Stabilisation work?
The process of binding the particles of the soil with additives essentially leads to ‘waterproofing’ the soil and making it more stable. So when road rehabilitation is being done, considerations such as strength and weight-bearing need play an important role to ensure the base is strong enough to support the volume and weight of forecasted traffic.
Traditional methods of stabilising soil foundations
Both bitumen and cement have been traditionally used as binding additives and are regarded as the accepted standard. However, these do have negative impacts on the environment and are also expensive resources. Using on-site materials such as crushed waste, sub-soils and excess stone waste are all examples of substances that can be used in rural dirt roads for stabilisation to diminish the amount of dust.
Technology and research into improving the way in which soil is stabilised, as well as the use of new binding methods are constantly being addressed. As an option, there is a range of polymer products which have been introduced into the market. These have found to be far more friendly to the environment and, when mixed correctly, improve the strength and weight-bearing capacity. Specific chlorides and fibre reinforcing are also alternatives. It is important for engineers and project managers to work closely with their laboratory so that a suitable mix for the application can be achieved.
In the diagram, one can see that all the materials are separated into hoppers and once the controller loads the correct mixtures into the control box, they are dropped into a ribbon mixer and produced as per the specification. Electronic control of this process renders a variance which is limited to 1.5%. Additional admixture hoppers can be installed on request to ensure mixture options are augmented.
Once the initial stage of the base has been completed, the machine can be easily cleaned to be ready for the next operation. Cold asphalt can be produced in the same unit to complete the road rehabilitation project.
Operators making use of soil stabilisation, will immediately recognise the advantages of using a multi-functional Blend Plant as a complete batching solution for any projects. In addition, this batching plant solution can be used in mining, construction or agriculture.
Innovation is a fundamental feature of Blend Plants Africa, paying attention to all aspects of the construction industry. Their professional teams recognise customer challenges and needs, leading to the development of solutions that will beneficially impact such activities. Blend Plants’ goal is to offer equipment that will improve the quality, the efficiency and, particularly, the profitability of all their customers’ projects.
MMI’s BLEND Plant solutions can cater for a wide choice of applications, whether it be soil stabilisation processes, bridge mix, laboratory specified mix, colour cement, backfill, cold asphalt or standard concrete. Contact Blend Plants for more information on your specific needs.