Skid Resistance Test The British Pendulum Tester PREPARED

Skid Resistance Test The British Pendulum Tester PREPARED BY: ASSISTANT LECTURER TEBA TARIQ KHALED

Purpose: This test method provides a measure of a frictional property, micro texture, of surfaces, either in the field or in the laboratory. This test method consists of using a pendulum-type tester with a standard rubber slider to determine the frictional properties of a test surface. This gives an indication of the pavement skid resistance.

Apparatus: 1. British Pendulum Tester 2. Rubber Slider 3. water and water container 4. Brush 5. Thermometer

Procedure 1. Test Area: Field test surfaces shall be free of loose particles and flushed with clean water. The test surface does not have to be horizontal. The instrument can be leveled in a working position using the leveling screws. 2. Apparatus Preparation: the British Pendulum instrument should be prepared as: A-Leveling: Level the instrument accurately by turning leveling screws until the bubble is centered in the spirit level. B-Zero Adjustment: Ensure there is no obstruction in the path of the swinging arm. Then press the release button. Observe the position of the pointer tip in relation to the zero setting on the scale plate. If the pointer is not with zero mark, adjust the friction pads by turning the locking ring. Repeat the operation until the pointer reaches the zero mark for at least three consecutive swings. C- Slide Length Adjustment: With pendulum hanging free, place spacer under adjusting screw of lifting handle. Lower pendulum so the edge of slider just touches the surface. Lock pendulum head firmly, raise lifting handle and remove the spacer.

Testing: A- Apply sufficient water to cover the pre-cleaned test area thoroughly. Execute one swing, but do not record reading. Catch the pendulum during the early portion of its return swing. While returning the pendulum to its starting position, raise the slider with its lifting handle to prevent contact between the slider and the test surface. Prior to each swing, the pointer should be returned until it rests against the adjustment screw. B- Make four more swings, rewetting the test area each time and record the results.

Calculation: Calculate the average value for the four consecutive British Pendulum values. BPV=(BPV 1+ BPV 2+ BPV 3+ BPV 4)/4 where: BPV: British Pendulum value The BPV should be adjusted due to the effect of pavement temperature by adding the skid resistance factor, according to the following chart.

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