Structural repairs have been carried out on a 35-km section – the stretch between the 11 and 46 kilometre marks – which extends from São Paulo in an easterly direction. And not before time, since the 25-cm cement-bound base course that lies under the asphalt was severely damaged due to the high daily volumes of some 125,000 vehicles in each direction, of which 15% comprise heavy goods vehicles.
Optimum solution: Cold recycling in-situ
Both Ecopistas and Fremix Engenharia e Comércio Ltda., the company contracted to rehabilitate the road surface, decided to use the technology that would deliver the best results in the fastest construction time: recycled material with foamed bitumen, produced in Wirtgen's mobile cold recycling mixing plant KMA 220.
When selecting the optimum rehabilitation method, the contractors also needed to meet one strict condition: on working days, the construction work on this vital transport route was restricted to an overnight 8-hour window from 9 p.m. to 5 a.m., since even the most minor closures for roadworks can cause massive traffic hold-ups. The tight timeframe meant that a thick asphalt pavement was out of the question. While the thicker asphalt layers produced in conventional rehabilitation processes need to cool for about four days – and for concrete pavements, setting takes even longer – Wirtgen's cold recycling technology allowed the pavement to be repaired section by section before being immediately reopened to traffic.
"During the daytime, no lanes can be closed between the São Paulo city limits and the airport, due to the high volume of traffic. That's why the work was carried out at night during the week or at weekends," explains Elio Cepollina Junior, Commercial Manager at Fremix. Further advantages of using this process include rapid completion of the works, a minimal number of transport journeys and the complete recycling of the reclaimed material. All in all, this adds up to a very cost-effective and eco-friendly process.