Road stabilization with polymers is a method used to enhance the performance and longevity of roads.
It basically consist in the incorporation of polymer materials during the construction or maintenance of roads to improve their mechanical properties, reduce maintenance needs, and increase the road resistance to environmental factors.
“Polymer” is a very broad term.
A polymer is a large molecule composed of repeating structural units (“monomers”), which are typically linked together through chemical bonds. Polymers can have a wide range of sizes and structures, and they can be made up of various types of monomers.
Polymers are very versatile: the properties of polymers can be customized by selecting the appropriate monomers, controlling the polymerization process, and modifying the molecular structure.
Road stabilization with polymers can be accomplished through various methods, including in situ mixing (polymers are mixed with existing soil), surface coating (a polymer-modified emulsion or slurry is applied to the existing road surface to improve its performance) or layer-by-layer construction (polymers are used in the construction of only one layer, such as the base or surface layer).
Using polymers for the stabilization of wind farms road can have many advantages: they can improve the load bearing capacity, increase the life of the roads, reduce earthworks and material consumption.
Some polymers can also protect against moisture infiltration and reduce the effects of freeze-thaw cycles.
They are basically an alternative to the “standard” technical solutions. In wind farms I see very often lime or cement stabilization (or, in some cases, geogrid or geotextile). All these alternatives are benchmarked against the “extreme option” – remove all unsuitable material.
I have also seen “hybrid” solutions. For instance, the Australian Polyroad is a mix of polymer and hydrated lime. The percentage of lime depends on the plasticity index of the material.
Other hybrid solutions are polymer-modified cement and asphalt mix with polymers.
Although I have not used a polymer solution myself, I believe that in some cases it can be the right solution, increasing CBRs, compressive strength and dry densities in the treated road sections.
The tricky part is that it seems that many synthetics polymers are commercial products and the exact formulation is confidential.
Acrylic or acetate polymers seems frequent – and they can be used not only as dust suppressors but also, mixed with granular material, to create a very hard layer.
The main reason why I have not yet had the pleasure of using these technical solutions in wind farms is only one: cost.
Compared to various alternatives, stabilisation with polymers was always more expensive (or at least, at a similar cost to another tried and tested and therefore considered ‘safer’ solution).
If any of you have had the opportunity to work with polymers, I would like to know your opinion.