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in overruns) (AFI 31-1043). Rigid pavement must be used as a foundation for sacrificial
polyethylene pads (installed at arresting gear cables) in both rigid and flexible
pavements (UFC 3-260-01).
Instrument Landing System (ILS) Runway Pavement. Reconstruction
of a runway threshold, or runway pavement near the threshold, requires that no
changes in grading within the ILS critical area occur, or the ILS system will require
General. Both rigid and flexible overlays are used. Overlays will
when an existing non-stabilized aggregate base course can be positively drained. When
the overlay includes a non-stabilized aggregate base course layer, the unbound base
course must be positively drained (UFC 3-260-02).
Hot Mix Asphalt (HMA) Overlays
Overlay Type. HMA overlays include flexible (non-stabilized base and
HMA wearing course) and all-bituminous concrete pavements. The all-bituminous
overlay is the preferred non-rigid type overlay to lessen the danger of entrapped
moisture in the overlay (UFC 3-260-02). Because of reflective cracking problems, all-
bituminous overlays of jointed concrete pavement are best suited as an interim
rehabilitation technique that postpones more comprehensive restoration of a
deteriorated pavement (UFC 3-260-02).
Reflective Crack Control. ETL 01-9 includes three procedures to mitigate
reflective cracking in all-bituminous overlays of jointed concrete pavements:
rubblization, saw-cut joints and seal, or crack/break and seat. These three techniques
can be used to control or mitigate reflective cracking. Use of any of the three techniques
is generally based upon the condition of the existing pavement and must be approved
by USACE-TSC, Air Force MAJCOM, or Navy EFD. If one of the reflective crack control
techniques is to be used, it should be included in the specified pavement overlay
General. Continuously reinforced, fibrous, and prestressed concrete
overlays will not be permitted unless technically and economically justified and
approved by USACE-TSC, Air Force MAJCOM, or Navy EFD (UFC 3-260-02).
Bonded Overlay. A fully bonded overlay is where the rigid overlay and
rigid base pavement are bonded and behave monolithically. Bonded overlays will only
be used on military airfields to correct surface deficiencies on pavement with C=1.00.
They are not suitable for structural upgrades unless the pavement is redesigned
assuming no load transfer (UFC 3-260-02).