Asphalt Paving.
Airfield asphalt pavement, laydown and compaction.
Echelon paving is the practice of paving two or more lanes side-by-side at the same time with the paving machines staggered. This reduces the number of longitudinal cold joints and their inherent problems are avoided.
The asphalt is delivered using rigid lorries with tipper bodies from the Asphalt batching plant.
Pavers on tracks spread the asphalt flat and provides minor compaction before it is compacted by rollers.
Compaction is achieved using.
Roller with steel tandem drums used for the initial rolling, aka breakdown rolling
Pneumatic Tire Rollers used for Intermediate rolling to knead the asphalt this achieved most compaction
Roller with steel tandem drums used to compact to an even and polished surface.
Ground Lights.
Installation of runway inset lights in asphalt pavement.
The inset lights comprise two main parts, the upper cover and a shallow base.
Ducts between the chambers and proposed lights are laid after the second layer of Crushed Aggregate Base Course is placed.
A Bobcat with a carbide tipped wheel saw is used to excavate the trenches. The cut material exits through openings on the side of the wheel saw housing.
The cable ducts are laid in the excavated trenches and the trenches are backfilled with concrete.
As-built coordinates of the duct tee under the proposed lights are taken and checked
After completion of the 3rd layer of crushed aggregate base course and asphalt paving the light bases are installed.
The land surveyor set out the center points of inset lights and off-set points.
Coring drill the recess to take the light base in the pavement, using a diamond-faced core drill mounted on a sturdy rig.
The drill core is removed.
A jig is used to accurately position the light base at the correct location, elevation and orientation.
The jig is a tripod frame used to maintain the light bases in place until the base is fixed.
The gap between the light base and pavement is filled up to 1cm below the top with epoxy in two steps in order to prevent the light base from floating. Firstly the space under the light base and the gap to the outside is filled up to 2-5 cm in order to prevent the base from floating.
The Jig is removed after the epoxy resin hardens.
Complete filling the gap around the light base using epoxy, up to 1 cm of the top.
The remaining 1 cm is filled with sealant.
The light upper cover is fixed to the base and connected to the electrical cable.
Runway Approach lights.
29 сен 2021
