1、Standard Specification for Rib-Tread Standard Tire for Special-Purpose Pavement Frictional-Property Tests AASHTO Designation: M 261-181Technical Section: 5a, Pavement Measurement Release: Group 1 (April) ASTM Designation: E501-08(2015) American Association of State Highway and Transportation Officia
2、ls 444 North Capitol Street NW, Suite 249 Washington, D.C. 20001TS-5a M 261-1 AASHTO Standard Specification for Rib-Tread Standard Tire for Special-Purpose Pavement Frictional-Property Tests AASHTO Designation: M 261-181Technical Section: 5a, Pavement Measurement Release: Group 1 (April) ASTM Design
3、ation: E501-08(2015) 1. SCOPE 1.1. This specification covers the general requirements for the standard rib tire for pavement friction testing. The tire covered by this specification is only for use in evaluation of tire-pavement friction such as that in T 242. 1.2. Terminology in this specification
4、is consistent with ASTM E867. 1.3. The values stated in SI units are to be regarded as the standard. 1.4. This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility o
5、f the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: T 242, Frictional Properties of Paved Surfaces Using a Full-Scale Tire 2.2. ASTM Standard
6、s: D297, Standard Test Methods for Rubber ProductsChemical Analysis D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic ElastomersTension D1765, Standard Classification System for Carbon Blacks Used in Rubber Products D2240, Standard Test Method for Rubber PropertyDurometer Hardness
7、D3182, Standard Practice for RubberMaterials, Equipment, and Procedures for Mixing Standard Compounds and Preparing Standard Vulcanized Sheets E867, Standard Terminology Relating to Vehicle-Pavement Systems 3. MATERIALS AND MANUFACTURE 3.1. The individual standard tires shall conform to the design s
8、tandards of Section 6. Dimensions, masses, and permissible variations are given in Section 6 and in Figure 1. 2018 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 3.2. Tread compounding,
9、 fabric 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 shoul
10、d be removed 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 E501, (Manufacturers name or trademark), Directional arrow on side of tire, and Rim: 15 6JJ. Figure 1Tire S
11、ection, Including Inflated Tire Dimensions 4. MATERIAL REQUIREMENTS 4.1. The compounding requirements for the tread compound are given in Table 1. Visual Wear Guide Line(Both Sides) consists of asmall raised circumferentialridge located on the shoulderof the tire 5.6 mm (0.22 in.)from the tread surf
12、ace.393.7 50.8-mm(15.50 2.0-in.)Tread Radius152-mm (6-in.)Rim Width212.1-mm (8.35-in.)Cross-Section Width703-mm (27.68-in.)Outer Diameter2.5-mm (0.10-in.)Under-FrictionTest Depth9.8-mm (0.385-in.)Friction Test Depth148.6-mm(5.85-in.)Tread Width(ARC)16.8 mm(0.66 in.)5.08 mm(0.20 in.) 2018 by the Amer
13、ican Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-3 AASHTO Table 1Compounding of Tread RubberaMaterial Parts per Hundred of Rubber (PPHR) SBR 1712b89.38 BR-1208c 35.00 N339d75.00 High-aromatic oil 22.12 Zinc
14、oxide 3.00 Stearic acid 2.00 6PPDe2.00 Paraffin wax 2.00 Sulfur 1.80 TBBSf1.10 DPGg0.10 aASTM D3182 bStyrene-butadiene rubber (23.5 percent styrene) 37.5 parts of high-aromatic oil cHigh cis-polybutadiene dN339 Carbon Black. See ASTM D1765. eDimethyl butylphenyl phenylenediamine fButyl benzothiazole
15、 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 duplication of properties of the finished tire may not be achieved with other similar products. This inclusio
16、n 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. PHYSICAL REQUIREMENTS 5.1. The physical and mechanical test requirements are given in Table 2. Table
17、 2Physical Requirements of Tread Compound Tensile sheet cure at 150C (302F), min 30 300% modulus, MPa (psi) (ASTM D412) 6.9 1.4 (1000 200) Tire tread durometer (ASTM D2240) 58 2 Specific gravity (ASTM D297) 1.13 0.02 Tensile strength, min, MPa (psi) (ASTM D412) 13.8 (2000) Elongation, min, % (ASTM D
18、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 are subject to manufacturers normal tolerances. 6.1.1. ConstructionThe tire shall be a size G78-15 tubeless
19、 type, belted bias construction (two body plies plus two belt plies). The tread width shall be 148.6 mm (5.85 in.) and the cross-sectional tread radius shall be 393.7 mm 50.8 mm (15.50 in. 2.0 in.). The tire shall have a recommended cross-section width of 212.1 mm (8.35 in.) and a recommended sectio
20、n height of 161 mm (6.34 in.) when mounted 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. 2018 by the American Association of State Highway and Transportation Officials. All rights
21、 reserved. Duplication is a violation of applicable law.TS-5a M 261-4 AASHTO 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 parallel from the tread surface down to a depth equal to the wear guideline. 6.1.3. GroovesThe tire
22、shall have six straight grooves of 5.08-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 shall have a uniform friction test depth of 9.8 mm (0.385 in.) maximum and shall have an under-t
23、read 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 grooves. These tread wear indicators shall be 1.6 mm (0.063 in.) deep and approximately 12.7
24、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 workmanship and material. 8. TEST METHODS 8.1. Tensile Sheet CuresASTM D3182. 8.2. Modulus (30
25、0 percent)ASTM D412. 8.3. Tensile Sheet DurometerASTM D2240, using a Type A Shore durometer. 8.4. Specific GravityASTM D297. 8.5. Tensile StrengthASTM D412. 8.6. ElongationASTM D412. 8.7. Tire Tread DurometerASTM D2240. 8.7.1. Use a Type A durometer 12.7-mm (0.5-in.) diameter presser foot. Shore, co
26、de 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 hardness. 8.7.4. The tire tread hardness is to be determined by averaging at least one set of six readin
27、gs. 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. 8.7.5. Apply presser foot to the tire tread as rapidly as possible without shock, keeping the foot parallel to the tread sur
28、face. Apply just sufficient pressure 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. 2018 by the Ameri
29、can Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-5a M 261-5 AASHTO 9. CERTIFICATION 9.1. Tires are to be inflated and measured prior to shipment. Upon request, the manufacturer shall furnish the purchaser certificatio
30、n 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 dry under ordinary atmospheric conditions in subdued light, 21 13.8C (70 25F). Tires should not be s
31、tored 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 designed for general highway service. Necessary transport of test equipment should be on commercial
32、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 psi) inflation. 11.4. The recommended static test load on the tire shall be 4826 N (1085 lbf) with l
33、oading to a maximum of 6138 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 irregular wear or damage results from tests or when the remaining groove depth in any groove is 4.
34、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. The magnitude of this dependence is a function of the water depth, pavement characteristics, tes
35、t 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 E501-08(2015). 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.
