Additional quality inspections of the asphalt mixtures with enhanced production control and monitoring the evacuation of tar asphalt.
From 13 July to 23 August, Brussels Airport has renovated runway 07L/25R. Given the great importance that Brussels Airport attaches to the quality of this work, COPRO was called on to closely monitor the quality of the asphalt mixtures used.
Certified products are in any case required by the constructor for this project. There is provision, for example, for factory production control by the manufacturer and an external control by an independent inspection body. This allows the constructor to ensure that the quality is monitored of each product and each production process.
For most projects this certification is sufficient and offers adequate confidence concerning the delivered product. However, runway 07L/25R is the airport’s main runway. During the works, no air traffic was possible on this runway and all aircraft were redirected to take off or land on another runway. This represented a major organisational challenge for the airport company. The works were therefore carried out in the shortest possible time span. The constructor and contractors worked 7 days a week/24 hours a day to limit the inconvenience as much as possible.
During the works, the top layers of the asphalt were broken out and replaced over almost the entire surface of the runway (3.3 km long and 45 m wide). This was the most important part of the renovation works. Together with the taxiways, this encompassed 270,000 m² or approximately 40 football pitches. The asphalt was produced in 3 different plants, and different finishers were applied to simultaneously process the asphalt. A real feat!
The constructor is of course building in a range of mechanisms, and extra controls to ensure that all the works are carried out perfectly: from the drafting of the specifications, the choice of construction method, the formulation of the execution times and planning, the choice of the proposed materials, the checks during implementation, to the choice and production of the asphalt mixtures. And it is precisely in this last step that Brussels Airport is calling on COPRO.
As an independent certification and inspection body, COPRO has extensive know-how concerning the building materials prescribed and used. Since 1983, inspectors have been carrying out inspections on the quality of, for example, asphalt, geotextile, guardrails, diverse concrete products, recycled aggregates … For this reason, Brussels Airport is asking COPRO to carry out extra checks on the asphalt produced in addition to the inspections that are carried out in the context of certification. COPRO was also in charge to ensure the correct disposal of the previous layers of tar asphalt.
An inspector from COPRO was always be present at the production locations of the producer during the preliminary study and production of the asphalt mixture. In this way, any possible deviation from the specifications could be detected immediately and the needed changes could be made on the spot. A total of 36 inspections and 280 hours of controls were done. The advice of COPRO was also requested when drawing up the specifications that were prepared by Brussels Airport and the Dutch engineering firm NACO.
Project leader Rik Derom of Brussels Airport Company: “Control of each step in the process surrounding the construction of the new asphalt layers is important to guaranteeing the quality of the final product. For this, Brussels Airport Company is drawing on the experience and knowledge of COPRO specifically regarding production of the asphalt mixture that was specially designed for renovation of the runway in question”.
COPRO not only supervised the quality control of the newly laid asphalt. Some of the removed layers contained tar asphalt and were transported by WILLEMEN INFRA under COPRO's supervision to REKO's thermal cleaning installation. By opting for this solution, the harmful tar binder is definitively removed from the chain and the remaining aggregates are once again 100% recyclable. With the COPRO.EXE implementation certificate in accordance with BRS 8049, the builder can be sure that his 8,000 tonnes of tar asphalt have been cleaned correctly and that the sustainability of the project is also taken into account.
The cooperation between Brussels Airport and COPRO therefore resulted in a more qualitative and sustainable end result, which is in everyone's interest.
Click here for more information about enhanced production control.
Click here for more information about the removal of tar-containing asphalt.