Maintaining Deflection Testing Maintaining Deflection Testing Equipment Dave Morrow Dave Morrow Dynatest Consulting, Inc. Types of deflection testing equipment equipment
Maintaining Deflection TestingMaintaining Deflection Testing Equipmentq p
Dave MorrowDave Morrow
Dynatest Consulting, Inc.
Types of deflection testing equipmentequipment
Light Weight Deflectometer (LWD)
Load up to 3,300 lbf (15kN) p ( )
Unbound materials (base, subgrade, …)
Falling Weight Deflectometer (FWD)
FWD: 1,500 – 27,000 lbf (7 – 120 kN)
FWD TMD
Heavy Weight Deflectometer (HWD)
HWD: 6,500 – 54,000 lbf (30 – 240 kN)
Other Dynatest productsOther Dynatest products
Friction testingFriction testing995 Tire Traction Tester
6875 Runway Friction Tester
1295 Locked Wheel Tester
Pavement ProfilingPavement Profiling
5051 Mk IV Portable RSP
5051 Mk III RSP
Heavy Vehicle SimulatorHeavy Vehicle Simulator
HVS Mk IV
HVS Mk VI
Typical FWD Testing
FWD/HWD Plate Diameter: try to match stress level (tire pressure)
Small Plate (300 mm ø ≈ 12”): Highways
Large Plate (450 mm ø ≈ 18”): Airports and Unbound layers
Number of drops per test location
One unrecorded seating drop [lowest load level: drop height 1]
Two/three recorded drops [various load levels or one load level]
Rigid PavementPortland Cement Concrete (PCC)Portland Cement Concrete (PCC)
Load Transfer Efficiency
`Curling/Warping Effects
FWD Star Bar
Load Transfer Efficiency at Longitudinal, Transverse Joints or Corners
S
Pressure Distribution + FWD Testingg
Properly maintained deflectionProperly maintained deflection equipment will:
• Spend less time on jobsite– Limited runway access
– Less exposure to trafficLess exposure to traffic
– Cheaper travel expenses
A id ibl d t i• Avoid a possible second trip
Properly maintained deflection equipment will:
• Have less down time– An F/HWD can earn $1,500 - $2,500 per day$ , $ , p y
– A breakdown on a closed runway will not earn points with OPSpoints with OPS
Properly maintained deflection equipment will:
• Yield better results; All analysis performed is based on data gathered g
Properly maintained deflection equipment will:
• Provide better data for your Pavement Management Systemg y– Over/under estimation of bearing capacity can
have a significant effect on maintenance costshave a significant effect on maintenance costs as well as remaining life calculations
Equipment maintenance has three aspects: mechanical
i lib ti d trepair, calibration, and operator involvementinvolvement
Mechanical repairs insure that the equipment won’t break down
Routine calibration insures that the d h d i lid ddata gathered is valid and
useableuseable
Operator involvementOperator involvement
Thank youThank you