Foamed asphalt recycling technique is put to perfect use in repair of Ayrton Senna Highway SP-070

Repair work on Ayrton Senna Highway SP-070, which began in June and was completed in November 2013, was one of the first in Brazil to use the foamed asphalt technique with cold RAP (Recycled Asphalt Product).

The Highway, which links São Paulo to Campos do Jordão, the Paraíba Valley and Rio de Janeiro, carries an average 90,000 vehicles in each direction every day. It is also the main access road to Guarulhos International Airport.

Improvements can be seen in both directions of the stretch, which measures approximately 35 km between kilometers 11 and 46 on SP-070. Due to heavy traffic on the highway, the pavement, consisting of a base layer with cement, was completely deteriorated.

The recycling and foamed asphalt, both done with the Wirtgen KMA 220 mobile cold recycling plant, was the repair technique that offered the best results. This choice was made after several experimental sections using different technology were studied over the course of twelve months, conducted by Fremix Engenharia e Comércio Ltda, the contractor responsible for carrying out the work along with Ecopistas, the concessionaire responsible for managing and maintaining the highway.

The Project

The structural plans were prepared by Loundon International, under the responsibility of engineer Dave Collings. The plans for the mixture were developed by JBA Engineering and Consulting Ltda (in collaboration with technicians from Loundon International), and the work was carried out by Fremix Engenharia e Comércio Ltda.

The project was done with 100% milled material, with the crushing being carried out by a cutting edge Kleemann MR 110 Z EVO impact crusher. For its part, the material removed from the road was recycled by a Wirtgen KMA 220 mobile cold recycler, which has a special chamber where the foamed asphalt is produced.

According to Juliano Gewehr, product specialist at Ciber Equipamentos Rodoviários, “Recycling using the cold mixing plant lets us completely make use of the material from the damaged lane, as well as allowing us to reinforce it with new materials, such as additives, cement and even civil construction demolition scraps, in the aim to prolong pavement life,” he explained.

Procedure

Reconstruction was done in two layers, the first being compaction of the RAP (Recycled Asphalt Product), for which the Hamm 3411 P compaction roller and the Hamm HD 90 tandem roller were used; the second was compacted with the HD 90 tandem roller. A fine layer of asphalt mixture with discontinuous grain size was laid on top of the recycled layer.

According to Elio Cepollina Junior, commercial director at Fremix, the greatest advantage of this technology was that it allowed them to quickly open up the highway to traffic after compaction, “From the São Paulo city limits and the airport, no lanes could be closed to traffic during the day, due to the large quantity of vehicles. "This being true, the work was done during the week at night and on weekends,” he added.

Despite the time limitations, they averaged 120 meters of production each night, and on the weekends, up to 500 m (4 meter wide lane).

Equipment

In all, eight pieces of Wirtgen Group equipment were put to work on the job, including a Vögele 1800-2 SprayJet paver, which simultaneously applies the asphalt curing emulsion - a material that promotes adherence between the new layer of asphalt and the base.

Wirtgen KMA 220 mobile mixing plant for cold recycling

With its 220 t/h production capacity, the cold recycling plant produces cold mixtures of additives and recycled asphalt materials with the addition of different binding agents like cement, mastic emulsion or foamed asphalt. Mounted on a semi trailer, it runs on its own diesel powered engine. Thanks to its compact, mobile design, transporting and setting up the machine is fast and easy at the construction site.

Kleemann MR 110 Z EVO mobile impact crusher

The Kleemann impact crusher is set up on a crawler track equipped chassis, which makes it very versatile. With a 350 t/h capacity, it can be used both for processing natural rock, recycled asphalt and demolition scrap material and for manufacturing extremely high quality end products. It has hydraulically controlled spacing adjustments, with a dual independent deck screen. As an optional feature, it can come equipped with a final screen with a return carrier for the additives that do not meet the grain size specifications for the project.

Hamm 3411 P Soil Compactor

In addition to its ergonomic operator seat, the 3411 P compactor provides a panoramic view, ideal for operation. Composed of a three point articulated chassis, which ensures safety and comfort, the compactor also features hydrostatic steering, factory standard traction to ensure its ability to climb, dual vibration frequency and amplitude, the largest stud area on the market to ensure better compaction with fewer passes on cohesive soil, easy maintenance and long intervals between repairs.

Vögele Super 1800-2 paver with SprayJet module

A special kind of paver, the Super 1800-2 with SprayJet module simultaneously applies the asphalt binding emulsion as it paves. With a working width of up to 6 m, it is equipped with a 5000 L emulsion tank that allows it to apply up to 1.6 kg/m² with its spray bars. Its compacting screed with tamper and vibrating plates ensures excellent pre-compaction of the final asphalt layer.

HD 90 Tandem Roller

The HD 90 features an ergonomic operator station, including steering wheel and rotating mobile instrument panel. With great visibility of the front and rear cylinder surfaces, the respective outer edges and work area..

Hamm GRW 280-16 Pneumatic Roller

Equipped with eight tires, the GRW 280-16 has a tire pressure control and anti-stick additive system, both operated from the control panel. Side windows on the chassis permit visibility of the edges of the tires. The operator station moves along a track and the seat can turn up to 90°. Its maximum operating weight is 24,000 kg, and can go up to 28,000 kg with additional ballast from the factory.

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