Hello, I’m Cecile Giacobi, I work for the toll motorway company VINCI AUTOROUTES, and I’m in charge of pavement management. - As an infrastructure manager, what are your expectations concerning pavement over your network? - Every day, over 2 million customers drive on our network of about 4,400 kilometers. We manage to continuously improve customer service. This has led to a policy setting out 32 commitments including offering comfortable and safe pavement, whatever the climatic conditions. This led to research high quality pavement products, adapted to all different exposures: low and high traffic, especially heavy traffic, cold and hot climate, snow and frequent freezing. - In order to reach these objectives, could you define the needs you have for the materials? - The desired characteristics are different for each layers of the pavement structure. The base courses, at the bottom of the pavement, constitute the most important layers for the road structure and to obtain long life pavement. For these layers, the need is to support the traffic loads, to transmit the strain to the subgrade and to ensure a good bearing capacity with time. Asphalt mixes should have high stiffness and resistance to fatigue. - What are the needs for the surface course? >> The surface layer, at the top of the pavement, is directly in contact with the traffic. The major objective is to provide high level of safety and comfort. To provide good adhesion in wet conditions, skid resistance and roughness are required. We also need rutting resistance, especially for the pavement supporting heavy traffic, like slow lanes, toll plaza or parking spaces. Other characteristics can also be required as the case may be: good drainage, noise reduction, cracking or stripping resistance. In addition to, for all materials, we expect low water susceptibility. And of course, long-term durability of these characteristics with traffic exposure is required. - What kind of methods do you implement to make sure the durability of the required characteristics will be reached? >> Every year, a condition survey is made to follow up the condition of the pavement, especially for surface characteristics. The results are input into a database and stored over time, allowing us to do statistics studies and get a good feedback. Based on this experience, we have defined technical requirements that we detailed in the contract of works companies. These requirements deal with all constituent materials, such as aggregates or bitumen, but also with the performance for asphalt mixtures. For example, we exclusively specify polymer modified bitumen for surface courses, because we have noticed that this prevents stripping and cracking. All these requirements should first be demonstrated with laboratory validation tests. Then, during the works, the quality and conformity product is frequently checked by tests and inspections. - Since a few decades, asphalt industry have offered the possibility to recycle and reuse reclaimed asphalt, does it change your requirements? - In some cases for maintenance operations, part of the pavement layers are milled off and replaced by new ones. The reclaimed asphalt can be reused to make new asphalt. From a sustainability and financial point of view, this is very interesting because less new bitumen and aggregates are required. When recycling asphalt, we have the same expectations for durability. Reclaimed asphalt is considered as a constituent material, with quality requirements and regular control. Most of the asphalt spread out each year on VINCI AUTOROUTES network contains reclaimed asphalt, with recycling rates up to 50%. - Do you have requirements for works realisation? - Reducing discomfort for our customers is a priority. This means limiting interventions for maintenance works while maintaining safety circulation conditions. The maintenance policy we have been applying for years has allowed long durability of the pavement materials and to increase the renewal periodicity of the surface courses. Otherwise, the works should be done in a short time period, generally during the night for motorways with high traffic. With asphalt materials such as very thin asphalt layer, we can easily and quickly renovate surface characteristics. Fast construction means shorter times for the workers on the construction site and more safety for the workers and road users. The key point to get the best policy in terms of pavement management is durability. This requires for the manager in charge with technical expertise to manage every aspects of the project from design to realization stages. Thank you for your attention.