ASTM-E501:08(R2020) pdf free download – Standard Specification for Standard Rib Tire for Pavement Skid-Resistance Tests.
8.3 Tensile Sheet Duromerer—Test Method D2240, using a Type A Shore durorneter.
8.4 Resto red Energy (Rebound or Resilience )—Te St Met hod D1054.
8.5 Specific Gravity—Test Methods D297.
8.6 Tensile Strength—Test Methods D4 12.
8.7 Elongation—Test Methods D4 12.
8.8 Tire iread l)um,neter—Test Method D2240. in addition to the following specific procedures:
8.8.1 Use a Type A durometer. (A 0.5-in. (12.7-mm) diameter presser foot, Shore, code XAHAF is recommended.)
8.8.2 The durometer shall be calibrated at a reading of 60 hardness.
8.8.3 Condition the tire and durometer to equilibrium at
73.4 ± 3.6 °F (23 ± 2 °C) before determining tread hardness.
8.8.4 The tire tread hardness is to he determined by averaging at least one set of six readings. A set is one reading taken in the center of each rib, excluding the center rib. It is recommended that additional sets of readings be taken around the tread circumference.
8.8.5 Apply presser foot to the tire tread as rapidly as possible without shock, keeping the foot parallel to the tread surface. Apply just sufficient pressure to obtain firm contact between presser foot and tire tread surface. Read the durometer scale within I s after presser foot is in contact with the tire tread, but after initial maximum transient which may occur immediately after contact is made.
9. Certification
9.1 Tires are to be inflated and measured prior to shipment. Upon request, the manufacturer shall furnish the purchaser certification that the test tire meets this specification.
9.2 All tires under certification shall be subject to the manufacturer’s normal variation.
10. Packaging and Preservation
10.1 The tires should be kept dry under ordinary atmospheric conditions in subdued light, 70 ± 25 °F (21 ± 13.8 °C). Tires should not be stored near electric motors, welders, or other ozone-generating equipment.
11. Recommendations for Tire Use and Operational Requirements
11.1 The tire is for skid testing only and is not designed for general highway service. Necessary transport of test equipment should be on commercial tires.
11.2 A new tire break-in of 200 miles (320 km) minimum should be made on tires by the purchaser before using the tire for testing.
11.3 The tire shall he operated with not less than 24 psi (165 kPa) inflation.
11.4 The recommended static test load on the tire shall be 1085 lhf (4826 N), with loading to a maximum of 1380 lbf (6138 N) permissible, at 24 psi (165 kPa) inflation.
11.5 When irregular wear or damage results from tests or when the remaining groove depth in any groove is 0.165 in.
(4.2 mm) or less, the use of the tire as a standard test tire shall be discontinued.
11.6 Caution- -Measured friction force and skid number (SN) may be infuenced by tire groove depth, or tread hardness,
or both. The magnitude of this dependence is a function of the water depth, pavement characteristics, test speed, and tire aging effects.