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Betoflex - Calgary Airport
The Calgary Airport is the third busiest airport in Canada after Toronto and Vancouver with over 15 million passengers every year. In the spring of 2015 the Airport Authority approached Standard General Inc. - Calgary (SGIC), a subsidiary of Colas Canada Inc., to find a paving solution to resolve a recurring permanent deformation issue in the waiting area of two taxiways leading to the takeoff area of the main airport runway. The paving solution needed to satisfy two important requirements: rapidity of execution to avoid minimize airport down time, resistance to rutting to alleviate surface deformation.
After discussions with the CST, Betoflex quickly emerged as a viable paving material solution for this particular application. The long history of successful applications of Betoflex in the group and the recent experience at the Toulouse airport provided solid references to convince the Airport Authority to allow SGIC to move forward with a technical proposition. Furthermore, Betoflex allowed SGIC to propose a rapid placement method to avoid any down time for the airport operation, which in this particular application was as critical as the technical performance of the paving material.
The formulation of the binder was carried out at the Colas Canada Inc. GECAN laboratory in Acheson, Alberta while the main mix-design development was performed at the CST.
The binder formulation was carried out using the new Multiple-Stress Creep-Recovery (MSCR) test as reference to achieve a PG 58E-28 binder. The development of this high performance binder, while maintaining viscosities for mixing and compaction at achievable temperatures was a challenge. The proposed binder was very similar to a Colflex type binder.
The Betoflex paving material was engineered as a 0/16 mm material to facilitate placement in a one 100mm lift layer and to reduce placement time. The rutting performance achieved in the laboratory using the French rut tester was less than 3.0 % at 30,000 cycles.
Taxiways Alpha and Charlie were rehabilitated using the method proposed by SGIC with nearly 3000 tonnes of Betoflex. The Airport Authority was pleased with the initial results considering that pavement surface temperature was above 50 °C mark on a regular basis in the summer of 2015 with no signs of deformation.