California Friction Testing At MnROADs (CA-342)

How Things WorkNovember 12, 2008

CA342 Friction Testing

CA-342 Equipment Operation

Smooth Tire

6 mm Offset Above Pavement

Distance Measuring Scale

Slide

Stand

Springs

Release

Shipping and Crating

Calibration of the Equipment

Glycerin Container

WD 40

Serrated Edge Calibration Plate

Mounting Plate

Environmental Trays

Power Cable

MnROADs Test Locations

Seven Friction Tests Conducted at Each Location (0, 5, 15, 30, 45, 90, 0 degrees)Three Locations Tested within Each Cell

MnROADs Cells Tested

Cell 7 NGCSCell 8 CDGCell 9 NGCS LiteCell 10 RTTCell 13 Astro TurfCell 15 AC

Operation of Test Device for Determining Effect of Test Angle on Friction Value

05 15 30 45

Testing at 90 Degrees

Placing Glycerin on Wheel and Pavement

Friction as a Function of Test Angle

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 10 20 30 40 50 60 70 80 90

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Deviaton from Direction of Travel (Degrees)

NGCS

CDG

NGCS Light

Random Transverse Tined

Asphalt Concrete

Astro Turf

Friction Index as a Function of Deviation from the Direction of Travel when Corrected For Cross Slope

Questions?