The Problem

In most countries throughout the world, the shortfall in resource funding made available for road network development, up-keep and maintenance is diminishing. This is due to other utilities such as

electricity, water, housing, schools and hospitals gaining higher level priorities and needs. In addition, obtaining proper road construction material is becoming scarce and extremely expensive as borrow pits are being depleted and haulage travel distances become unbearably longer. This is forcing a “re-think”, re-evaluation and re-design of conventionally designed, material standards and construction methods.

Engineers have to re-evaluate the standard specifications by reducing the requirements to more appropriate and achievable yet appropriate methods and standards. They will need to take into consideration direct and actual traffic loads and the maintenance thereof.

However, this leads to further additional problems, in particular the impact on un-surfaced gravel roads, which include:

• Maintenance problems of the road surface and drainage, under wet and dry conditions.
• Deterioration of the surface drainage as the traffic increases due to heavier axle loads (rutting and potholes), usually caused by using inferior materials and standards.
• In addition, aggravated dust is created which have a direct impact on road surfaces (material loss, pavement structure failure and corrugation), surface water drainage, environmental, health and safety.
• Experienced operators/road builders can improve the surface problems, but this maintenance is costly and disruptive to the traffic flow.

The material requirements for low traffic volume roads can be substantially lowered compared to those for high traffic volume roads, by making use of in-situ materials as much as possible.

These materials may need to be blended or modified to produce appropriate pavement structured materials. This has the added a further negative disadvantage on the environmental impact created by road construction with imported materials from elsewhere.

The main factor influencing the strength of soils is the presence of water, and one of the main reasons for moisture related road failures is the presence of clay material, either in the soil or from partly weathered aggregates. Using local or in-situ materials increases the presence of clay minerals and this in turn increases the moisture sensitivity of the material, thus reducing the strength of the pavement layer.

The Solution

With the above in mind, EL-SSS is a unique product that has been developed in South Africa to treat the material by increasing the shear strength of the soil and decreasing the influence of moisture susceptibility of clayey materials. The main advantage of using EL-SSS is that only a small volume of product is required and all types of soils consisting of fine particles can be treated. EL-SSS has the ability to stabilize the subgrade of natural materials, without making use of additives, hydraulic binders or blending with coarse aggregate, in order to support extreme traffic (ever increasing) loads.

 
The use of EL-SSS means that a wider range of soil materials (previously not considered) can be now be confidently used. This gives the engineers more scope and potential to use the natural in-situ material in single or multi-layer pavement structure, by reducing the import of materials from unsightly and environmentally degrading borrow pits. In addition, further minimising the negative environmental impact.

 
In addition, past experience has been observed and proven that dust on a EL-SSS treated road is substantially less than the untreated road surface, often up to 80% to 90% dust suppression / reduction.

 
EL-SSS has been extensively and positively used in many countries to overcome the problem of using “sub-standard” quality construction materials for road pavement construction / layer works.

Construction and maintenance costs of EL-SSS treated unpaved or paved Roads, Railway lines, Airports, Military airports, Harbours, Landfills, Renewable Energy Plants, solar farms, etc, can save vast 30 to 60% of conventional method of road construction.

 
Below is a cost optimization table of projects completed by EL-SSS. It identifies the cost comparison cost percentile saving.