Asfaltos | TDM

THE PROBLEM:

The Rutas de Lima concessionaire needed to carry out a functional intervention on high-traffic sections of the Panamericana Sur and Norte (approximately 400,000 m²), a road characterized by an extremely high heavy-load vehicle flow. The challenge was to implement a solution that met four critical conditions:

• To have a functional solution, using an ultra-thin asphalt mix, capable of providing a high-quality level of service for a road with extremely high traffic volume.
• To have a solution highly resistant to permanent deformation, while also offering excellent resistance to reflective cracking.
• To have a solution with excellent friction levels, capable of providing comfort and safety to road users.
• That the ultra-thin asphalt mix could be applied during nighttime hours (between 11:00 PM and 4:00 AM), within a short work window, requiring high application performance while also allowing the road to be reopened to traffic immediately upon completion of the work shift.

THE SOLUTION:

The Rutas de Lima concessionaire, in strategic partnership with COPAVEL and with the technical support of TDM, conducted an exhaustive study and analysis of different solution alternatives and decided to use a warm ultra-thin asphalt mix as the solution to the functional problem — referred to as hot micropaving — which also meets the requirements of an SMA 8 (Stone Mastic Asphalt) ultra-thin asphalt mix at 1″ thickness. It is important to highlight that this solution used an asphalt binder meeting the PG performance grade required for the project’s climatic and traffic conditions, produced by TDM under the commercial name Betutec 60/85 PG 76-22E warm mix.

The key components of this technical solution were:

• The use of a gap-graded aggregate gradation to create a load-bearing mineral skeleton equivalent to that of an SMA (Stone Mastic Asphalt) asphalt mix.
• Incorporation of cellulose fibers to stabilize the asphalt binder and prevent draindown, while also achieving a highly homogeneous mix that provides excellent resistance to permanent deformation as well as reflective cracking, consistent with an SMA asphalt mix.
• A precise combination of fines, fiber, and modified asphalt binder that creates a matrix capable of absorbing stresses without cracking.
• Implementation of warm mix technology, which allowed ultra-thin mixes to be applied during nighttime hours with very long transport and waiting times, resulting in an installed asphalt mix of excellent quality with the compaction densities specified in the project.

BENEFITS:

The ultra-thin asphalt mix (hot micropaving) demonstrated extraordinary performance, equivalent to that of an SMA 8 ultra-thin asphalt mix, ideal for the demands of the Panamericana Sur and Norte, which carry extremely high traffic volumes.

The warm mix technology used in this solution enabled extended transport and waiting times, ensuring the quality and placement of the mix on-site during nighttime work shifts.

Performance test results, as part of the on-site quality control policy, confirm excellent resistance to permanent deformation, reflective cracking, and high skid resistance.

The mix gradation, equivalent to the SMA mix, combined with the modified asphalt designed for the project’s climatic and traffic conditions, ensures a high-performance asphalt mix — one that, after one year of monitoring, continues to deliver outstanding results.