FROM MAPEI: SPECIFIC PRODUCTS FOR BITUMINOUS CONGLOMERATE
To upgrade the surfacing of the runways, a deep channel was milled out and then rebuilt along the central strip of the runways, while in the remaining areas of the runways, the wear layer only was removed and a new one was installed.
For this project, Mapei supplied products specifically designed for the bituminous binder and base course layers for around 400,000 m2 of new surfacing for the aprons, taxiing areas, entrance/exit areas of the runways and the runways, as well as technical support during the mix design phase and application phase of the mixes.
Going into detail, the following products were supplied:
• MAPEI ACF-L2 regenerating liquid admixture for bitumen for the base course and binder layers;
• MAPEPLAST PAVI 02 polymer used in the production of modified bituminous conglomerate for the base course and binder layers.
The benefits of using these admixtures may be summarised as follows:
- Adding MAPEI ACF-L2 allowed high amounts of RAP (Reclaimed Asphalt Pavement) to be used in the base course and binder layers. MAPEI ACF-L2 significantly improves the rheological properties of the bitumen in the RAP by reintegrating its maltene component (an oily resin present in the original bitumen) consumed by oxidisation and ageing processes. MAPEI ACF-L2 also improved adhesion of both the virgin and regenerated bituminous agglomerate, thanks to its special formulation containing synthetic adhesion promoters.
- The use of MAPEPLAST PAVI 02, which was used in addition to MAPEI ACF-L2 in the base course and binder layers, helped to improve the adhesion of the virgin and recycled bituminous components to the aggregates.
Adding MAPEPLAST PAVI 02 to the bituminous conglomerate also increased the shear modulus of the conglomerate and the benefit of this admixture is that it significantly improves the resistance of the surfacing to fatigue and permanent deformation (or rutting, which forms along the trajectory of the wheels of aircraft).