IPRF-03-1 Project Progress on: Best Practices Guide for In-Pavement Lighting, Portland Cement Concrete Pavement Sponsored by: FAA, in Cooperative Agreement with Innovative Pavement Research Foundation (IPRF) Ornulv (Arnie) Sonsteby, P.E. Penn State/FAA Airport conference 2008 Hershey, PA
Fact -- A 2-mile “low visibility” runway may have 800+ in-pavement lights. A a major airport may have 5,000 or more in-pavement lights. This represents a significant airport investment -- for initial installation, and out-year maintenance.
Why this Document? Pavements and In-Pavement lights have different criteria based on function Light base is a penetration in otherwise uniform pavement with planned joints Installation of light base is KEY to meeting light tolerances
Concrete Encasement and Rebar Cage Light base is Interface with pavement Anchor during Paving operation Strengthens Installation
Key Pavement Tolerances Guidance: FAA AC 150-5320-6 • Promote Drainage • Smoothness for Traffic PURPOSE: • Height • Smoothness +/- 1/2” inch (deviation from design profile) +/- 1/4” inch in 16 feet
Difficult Joint Conflicts • Transverse joints, OK • Longitudinal joint difficult TDZ Lights: • Close spacing • Arcs oblique to joints TW CTL Lights: • Close spacing • Longitudinal joint conflict In-Pavement RGL & Stop Bar Lights:
C L RW Centerline and TDZ Lights TDZ Contraction Joint (typ) Construction Joint (typ) 20’ Typ PCC Panel 18.75’ R/W RW CL
C L Lead-off / Lead-on Lights Contraction Joint (typ) Typ PCC Panel 18.75’ 20’ Construction Joint (typ) LOF / LON R/W RW CL
Resolving Joint Conflicts 2’ clear from joint Requirement --- In design --- • Coordinate pavement joints with required light locations • Use allowable tolerances to de-conflict • Last resort – use Boxout
Key Lighting Tolerances Guidance: FAA AC 150-5345-30 (also UFC 5-535-01) • Visual signal (pattern) • Photometric requirements • Resistance to snow plows • Minimal impact on “ride” PURPOSE: • Layout • Azimuth • Height • Level varies for each system +/- 1/2 deg (relative to pavement elevation on low side) +0”/-1/16” None given (Engineer decide)
Height Check HEIGHT of fixture edge at low side of pavement
Height Straightedge: ~ 7’L x 6”-8”H Notch 1”x14” for Size B base • Check HEIGHT at fixture edge on low side of pavement • Check for obstruction in beam direction
Azimuth +/- 1/2 deg Line of lights BEAM • Aim is usually parallel to line of lights, or RW/TW centerline • Some lights are “toed-in”, e.g.: • RW edge lights (3.5 deg toe-in) • TDZ lights (4 deg toe-in) • Unidirectional TW center lights on an arc are aimed into curve (to 4th light ahead) Orientation of light base bolt holes is key to azimuth aim
Level +/- ? Lights to be installed level. (no tolerance in AC) Tilting light into grade blocks more light beam
Resolving Joint Conflicts Resolving TDZ Lights --- • 2’ minimum separation should always be used with CONTRACTION joints. • Structurally, < 2’ may be OK with CONSTRUCTION joints (may require FAA “deviation from standards”. • Consider accepting 1.5’ separation from longitudinal construction joint (preferred over boxout).
Resolving Joint Conflicts Contraction Joints --- • Do not install light base closer than 2’ to a contraction joint. • The contraction crack that forms as part of the concrete hydration process will typically propagate to a pavement penetration if < 2’ from joint. • If coordination and tolerances can’t resolve, boxout is only option.
Resolving Joint Conflicts Construction Joints --- • < 2’ to a construction joint can work, provided: • Provisions are made for paving machine clearances • Load transfer is considered • Rebar cage should not cross joint. • If closer than 12” to joint and a dowel bar is within 12”, omit dowel bar or adjust dowel spacing (not considered detrimental to load transfer efficiency). • If 2 dowels must be omitted, extend concrete encasement for light base (anchor) across the joint to support joint edge of the 2 panels.
Boxout at PCC Construction Joint Use WWF in all panels adjacent to boxout Change to construction joint when boxout is used on a planned contraction joint. Size of boxout increases as location of the light base moves away from joint.
Boxout at PCC Joint Intersection Use WWF in all panels adjacent to boxout
Full Depth Partial Panel Replacement Size of boxout increases as location of the light base moves away from joint. Change to construction joint when used on a planned contraction joint.
Installation Quality • Successful installation is DIRECTLY dependent upon installation of the light base. • Quality is a function of: • Good design and construction documents • Good craftsmanship by the installer • Attentive Quality Control. • QC is even more important where time constraints require accelerated construction.
Impact of Deficient installation For contractor --- Setting a light base too close to a joint, or out-of-tolerance wrt location, height relative to surface, azimuth, and level, may require removal and replacement.
Capabilities Bad news – Installed bases are rejected. Good news – Problem is identified prior to paving!
Impact of Deficient installation For User --- • Failure to meet light tolerances=> deficient photometrics • Failure to meet pavement performance requirements=> increased maintenance
SUMMARY • Coordinate between disciplines (pavement, electrical, survey) • In Design & during Construction • Check frequently • Catch errors early
Emerging Trends in Airfield Design and Construction Joe Vigilante, P.E. Penn State/FAA Airport Conference 2008 Hershey, PA
Emerging Trends Runway Status Lights (RWSL) LED Lights Pre-Purchase Material
Runway Status Lights (RWSL) • FAA Engineering Brief – EB-64A • Draft AC150/5340-30D – Appendix 7, Runway Status Light System (RWSL) • www.rwsl.net
System Components • FAA Ground Surveillance System • Interfaces with Airport Surface Radar (ASDE) and Localized Transponders/Radar • Field Lighting Control System (FLCS) • In-pavement Lights with Local Control Units
Field Lighting Control System (FLCS) • Runway Entrance Lights (REL) • Single Row of In-pavement Lights Parallel to TW Centerline • Take-off Hold Lights (THL) • Two Rows of In-pavement Lights Parallel to RW Centerline
Runway Entrance Lights(REL) ANGLED CONFIGURATION LAYOUT
Runway Entrance Lights(REL) • Pavement and Lighting Tolerances • Coordinating Lights with Paving Joints • Importance of Quality Control PERPENDICULAR CONFIGURATION LAYOUT
Take Off/Hold Lights PROPOSED LOCATIONS
Design Layout RWSL CONDUITS IN KERF: TCL, REL & RWSL TDZ RCL TCL RWSL TCL REL CONDUITS IN KERF: TCL, RCL & RWSL RWSL CONDUITS IN KERF: RCL & RWSL RCL TDZ CONSTRUCTABILITY
Rundown • RWSL: • Moving Forward – Think – Coordinate • Designs are Being Completed – Heading into Paving Season • Critical to Install Infrastructure
LED Airfield Lights • Various Fixtures – (+/-) 8 Years • Technology Continuously Improving • Range of Regional Installations
Introducing LEDs to an Incandescent Field • Northeast Moving Cautiously • More Requests • One Step at a Time
Choosing the One • Other than Primary Airfield Lights • Short Taxiway • Low Traffic or Cargo Usage • Buy-in From Facility
The Candidate • Dead-End Cargo Carrier Taxiway • Approximately 3,600-ft.-long • 70 Taxiway Centerline Lights
The Plan • Mix of FAA-certified Manufacturers • No Heaters • Segregated Circuit • Baseline Photometric Test
Pre-Purchase Material • Goal – Procure Long Lead Time Items and Time Critical Items • Quick Start to Construction • Aids in Construction Phasing • Shorter Shutdowns
Definitions • Pre-Order – Procurement of Material by the Airport • Stockpile – On-Site Supply of Material to Minimize Ordering During Construction • Material Examples • Light Bases • Series Lighting Cable • CCR Line-Ups
The Process • Identify Material • Purchasing Bill of Material • Coordinate Receiving and Storage
Advantages • Speed-Up Construction Start • Reduce RW/TW Closures • Light Systems Energized Quicker
Disadvantages • Pavement Design • Additional Procurement Step • Higher Cost – Over-Purchase of Material