1、Standard Specification for Rib-Tread Standard Tire for Special-Purpose Pavement Frictional-Property Tests AASHTO Designation: M 261-96 (2013)1ASTM Designation: E 501-08 American Association of State Highway and Transportation Officials 444 North Capitol Street NW, Suite 249 Washington, D.C. 20001TS-
2、5a M 261-1 AASHTO Standard Specification for Rib-Tread Standard Tire for Special-Purpose Pavement Frictional-Property Tests AASHTO Designation: M 261-96 (2013)1ASTM Designation: E 501-08 1. SCOPE 1.1. This specification covers the general requirements for the standard rib tire for pavement friction
3、testing. The tire covered by this specification is only for use in evaluation of tire-pavement friction. 1.2. Terminology in this specification is consistent with ASTM E 867. 1.3. The values stated in SI units are to be regarded as the standard. 1.4. This standard may involve hazardous materials, op
4、erations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prio
5、r to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: T 242, Frictional Properties of Paved Surfaces Using a Full-Scale Tire 2.2. ASTM Standards: D 297, Standard Test Methods for Rubber ProductsChemical Analysis D 412, Standard Test Methods for Vulcanized Rubber and Thermoplastic ElastomersTension
6、 D 1765, Standard Classification System for Carbon Blacks Used in Rubber Products D 2240, Standard Test Method for Rubber PropertyDurometer Hardness D 3182, Standard Practice for RubberMaterials, Equipment, and Procedures for Mixing Standard Compounds and Preparing Standard Vulcanized Sheets E 501,
7、Standard Specification for Standard Rib Tire for Pavement Skid-Resistance Tests E 867, Standard Terminology Relating to Vehicle-Pavement Systems 3. MATERIALS AND MANUFACTURE 3.1. The individual standard tires shall conform to the design standards of Section 6. Dimensions, masses, and permissible var
8、iations are given in Section 6 and in Figure 1. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-2 AASHTO Figure 1Tire Section, Including Inflated Tire Dimensions 3.2. Tread compounding, fabri
9、c processing, and all steps in tire manufacturing shall be certified to ensure that the specifications are met. 3.3. A small raised guideline shall be molded on the tire shoulder area to provide a rapid visual check as to whether the maximum wear level for testing has been reached. Tires should be r
10、emoved from service as recommended in Section 11.5. The marking on the tire should include the following information: G78-15, Standard Pavement Test TireNot for General Highway Use, ASTM E 501, (Manufacturers name or trademark), Directional arrow on side of tire, and Rim: 15 6JJ. 2014 by the America
11、n Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-3 AASHTO 4. MATERIAL REQUIREMENTS 4.1. The compounding requirements for the tread compound are given in Table 1. Table 1Compounding of Tread RubberaMaterial Parts
12、 per Hundred of Rubber (PPHR) SBR 1712b89.38 BR-1208c 35.00 N339d75.00 High-aromatic oil 22.12 Zinc oxide 3.00 Stearic acid 2.00 6PPDe2.00 Paraffin wax 2.00 Sulfur 1.80 TBBSf1.10 DPGg0.10 aASTM D 3182 bStyrene-butadiene rubber (23.5 percent styrene) 37.5 parts of high-aromatic oil cHigh cis-polybuta
13、diene dN339 Carbon Black. See ASTM D 1765. eDimethyl butylphenyl phenylenediamine fButyl benzothiazole sulfenamide g Diphenyl guanidine 4.2. FabricThe fabric shall be polyester body or carcass plies and fiberglass belt plies. Note 1Certain proprietary products have been specified since exact duplica
14、tion of properties of the finished tire may not be achieved with other similar products. This inclusion does not in any way comprise a recommendation for these proprietary products or against similar products of other manufacturers; nor does it imply any superiority over any such similar products. 5
15、. PHYSICAL REQUIREMENTS 5.1. The physical and mechanical test requirements are given in Table 2. Table 2Physical Requirements of Tread Compound Tensile sheet cure at 150C (302F), min 30 300% modulus, MPa (psi) (ASTM D 412) 6.9 1.4 (1000 200) Tire tread durometer (ASTM D 2240) 58 2 Specific gravity (
16、ASTM 297) 1.13 0.02 Tensile strength, min, MPa (psi) (ASTM D 412) 13.8 (2000) Elongation, min, % (ASTM D 412) 500 6. DIMENSIONS, MASSES, AND PERMISSIBLE VARIATIONS 6.1. GeneralDetails of dimensions are listed as follow and are shown in Figure 1. Where tolerances are not specified, tire dimensions ar
17、e subject to manufacturers normal tolerances. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-4 AASHTO 6.1.1. ConstructionThe tire shall be a size G78-15 tubeless type, belted bias constructi
18、on (two body plies plus two belt plies). The tread width shall be 149 mm (5.85 in.) and the cross-sectional tread radius shall be 394 mm 51 mm (15.50 in. 2.0 in.). The tire shall have a recommended cross-section width of 212 mm (8.35 in.) and a recommended section height of 161 mm (6.34 in.) when mo
19、unted on a Tire and Rim Association 15-by-6-in. (381-by-152-mm) JJ rim. The cured crown angles shall be 33 2 degrees for the body plies and 27 2 degrees for the belt plies. 6.1.2. RibsThe tire shall have seven plain ribs of 16.8-mm (0.66-in.) width each. Both sides of the shoulder ribs shall be para
20、llel from the tread surface down to a depth equal to the wear guideline. 6.1.3. GroovesThe tire shall have six straight grooves of 5.1-mm (0.20-in.) width each. Each groove shall be parallel to the radius of the tread radius arc and shall have a full radius at the bottom of the groove. Each groove s
21、hall have a uniform friction test depth of 9.8 mm (0.385 in.) maximum and shall have an undertread thickness of 2.5 mm (0.10 in.). 6.1.4. Wear IndicatorsThere shall be six rows of tread wear indicators spaced uniformly around the tire circumference and directly across the full tread width in all six
22、 grooves. These tread wear indicators shall be 1.6 mm (0.063 in.) deep and approximately 12.7 mm (0.50 in.) long. A visual wear guideline shall be located on the shoulder of the tire 5.6 mm (0.22 in.) from the tread surface as shown in Figure 1. 7. WORKMANSHIP 7.1. Tires shall be free of defects in
23、workmanship and material. 8. TEST METHODS 8.1. Tensile Sheet CuresASTM D 3182. 8.2. Modulus (300 percent)ASTM D 412. 8.3. Tensile Sheet DurometerASTM D 2240, using a Type A Shore durometer. 8.4. Specific GravityASTM D 297. 8.5. Tensile StrengthASTM D 412. 8.6. ElongationASTM D 412. 8.7. Tire Tread D
24、urometerASTM D 2240. 8.7.1. Use a Type A durometer 12.7-mm (0.5-in.) diameter presser foot. Shore, code XAHAF is recommended. 8.7.2. The durometer shall be calibrated at a reading of 60 hardness. 8.7.3. Condition the tire and durometer to equilibrium at 23 2C (73.4 3.6F) before determining tread har
25、dness. 8.7.4. The tire tread hardness is to be 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. 2014 by the American As
26、sociation of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-5 AASHTO 8.7.5. Apply presser foot to the tire tread as rapidly as possible without shock, keeping the foot parallel to the tread surface. Apply just sufficient press
27、ure to obtain firm contact between presser foot and tire tread surface. Read the durometer scale within 1 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
28、 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 manufacturers normal variation. 10. PACKAGING AND PRESERVATION 10.1. The tires should be kept
29、dry under ordinary atmospheric conditions in subdued light, 21 14C (70 25F). 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 pavement friction testing only and is not de
30、signed for general highway service. Necessary transport of test equipment should be on commercial tires. 11.2. A new tire break-in of 320 km (200 mi) minimum should be made on tires by the purchaser before using the tire for testing. 11.3. The tire shall be operated with not less than 165 kPa (24 ps
31、i) inflation. 11.4. The recommended static test load on the tire shall be 4825 N (1085 lbf) with loading to a maximum of 6150 N (1380 lbf) permissible, at 165 kPa (24 psi) inflation. 11.5. Tire should be mounted so that it is rotated in the direction of the arrow on the side of the tire. 11.6. When
32、irregular wear or damage results from tests or when the remaining groove depth in any groove is 4.2 mm (0.165 in.) or less, the use of the tire as a standard test tire shall be discontinued. 11.7. CautionMeasured friction force or friction number may be influenced by tire tread depth and/or hardness
33、. The magnitude of this dependence is a function of the water depth, pavement characteristics, test speed, and tire-aging effects. 12. KEYWORDS 12.1. Friction; pavement; rib tire. 1Except for terminology, figures, and the use of SI units, this specification agrees with ASTM E 501-08. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
