Highway Slip Friction Tester HFT
The Highway Slip Friction Tester (HFT) is an accurate and repeatable, self-contained continuous measuring device that provides self-wetted coefficients of friction on highway pavements.
It is designed for maintenance testing to evaluate pavement friction changes due to weathering, traffic, aging, and contaminants. It can be used in difficult test areas, such as bridge decks, off-ramps, city streets, and intersections, giving an accurate continuous friction trace for the area being tested.
The Highway Slip Friction Tester are particularly important during adverse weather conditions, such as rain, snow, or ice when the pavement surface can become slippery and reduce a vehicle’s ability to stop or maneuver safely. The data can then help engineers and maintenance crews make informed decisions about the suitability of the road surface for safe vehicle travel.
- The Highway Slip Friction Tester (HFT) is a fully instrumented vehicle that uses a Dynatest Two Axis Force Transducer mounted on a retractable fifth wheel assembly. The test gear is mounted adjacent to the left or right wheel of the vehicle to allow safe wheel track testing.
- This assembly provides real-time vertical load and horizontal tractive force measurement. The fifth wheel assembly is driven at 14% slip. The Highway Slip Friction Tester (HFT) meets the requirements of ASTM Standard E2340 for fixed slip friction measurement.
- System electronics include laptop computer with user-friendly Windows® software allowing the operator to enter customised test patterns, test type (manual or automatic), and to annotate pavement test conditions for later reference.
- The friction values, along with vehicle speed, temperature, and water flow rate data are stored and can be printed out during testing or post-test.
- The system includes a minimum 250 U.S. gallon (1000 liter) water tank, positive displacement water pump, and laminar flow water nozzle to allow for wet pavement testing on up to 72,000+ft. (22000+m) of pavement with a water film thickness of 0.02in (0.5mm).
Options available: DGPS, texture laser for MPD data collection, ROW camera for imagery, temperature sensors.