Environmental issues

The world of road construction is looking for solutions that limit the ecological impact. Maintenance policies are now oriented towards recycling bituminous materials, as well as solutions that limit the amount of waste produced, a factor closely linked to the need for natural resources.

Our solutions at much lower depths than conventional reinforcement solutions allow us to limit the ecological impact of a pavement restructuring in:

• Significantly reducing the use of mineral raw materials that are becoming scarcer (gravel and oil)
  
• Significantly reducing the amount of waste to be disposed of and treated, resulting from the faulty road structure
  

Polycyclic Aromatic Hydrocarbons (PAHs) were introduced into pavements by the use of tar (from coal distillation) until 1993, or other fluxes or coal derivatives until 2005.

The presence of PAHs within bituminous pavement structures remains quite frequent to this day. Although they are sometimes present in quantities that allow asphalt mix recycling (according to applicable standards), PAHs are in most cases the reason for waste generation.

Indeed, asphalt heavily polluted with PAHs will have to be treated in a specialized landfill: it is then not recyclable. We may note that the specific facilities for treating this waste are very expensive and do not have infinite capacity. Depending on the surface to be treated, the presence of PAHs can be a guiding development axis, which can influence the economic viability of the project.

The presence of these PAHs also requires the adequate protection of all personnel involved in a site concerned, in order to limit any risk of intoxications, PAHs being carcinogenic.

Despite their negative aspects, PAHs have an interesting characteristic: they are neither polluting nor dangerous as long as they are buried in asphalt pavements that should not be milled.