Ayrton Senna Highway – São Paulo – Brazil – pavement repair project uses cold recycling with foamed bitumen

Ayrton Senna Highway – São Paulo – Brazil – pavement repair project uses cold recycling with foamed bitumen

The use of foamed bitumen

The Ayrton Senna Highway (SP-070) is undergoing a structural repair of its pavement between kilometers 11 (São Paulo) and 46 (Mogi das Cruzes exit). This is the first road repair project that uses the technique of cold recycling in-plant with foamed bitumen.

"No doubt this project will be a turning point in road construction in Brazil, overcoming the inertia and resistance to the use of foamed bitumen in projects building roads with a high traffic volume," explains Valmir Bonfim, Technical Director from FREMIX, the contractor responsible for the project. This technique was applied on an experimental stretch of road in October 2011, which is still intact. The conclusion of the project will be in November this year.

The choose of the right paver

Eight pieces of equipment from the Wirtgen Group are working at the site and the highlight is the Vögele 1800 Spray Jet paver, which is the only model of paver capable of carrying out jobs that use this type of technique. It distributes the layers of foamed reclaimed asphalt pavement (RAP) and of the Gap Graded mixture. One of the main characteristics of this compact paver is the various application possibilities it offers.

The equipment used

The crushing of the milled material (RAP) is being done with a Kleemann MR 110 Z EVO crusher. The old pavement is being milled by two large Wirtgen milling machines models W1900 and W200. The reclaiming of this material removed from the road is being done by a Wirtgen KMA 220 mobile cold recycling mixing plant. There is also the participation of three Hamm rollers: the model 3414 works on compressing the foamed RAP layers and two rollers model HD-90 work on the application of the layer.

The technical director of FREMIX explains that the choice for Wirtgen Group equipment was made because of their quality and reliability. "In a job of this magnitude, where it is necessary to finalize the recovery of a particular section on the same day, we cannot take any risks. For this reason we opted for reliable equipment and preferably new," explains Valmir Bonfim.

The quality of the job site

The process performed at the site begins with the removal of the surface layer and the entire cement layer that is deteriorated. "This is the great advantage of recycling in-plant: it is possible to analyze the remaining pavement, opt for deeper milling, perform measurements of deflection, reinforce the sub-base, etc. In this project, for example, some localized interventions were done such as a reinforcement layer and better drainage in order to extend the life of the pavement even further," concludes Valmir Bonfim.