1、Designation: D3319 11 (Reapproved 2017)Standard Practice for theAccelerated Polishing of Aggregates Using the BritishWheel1This standard is issued under the fixed designation D3319; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a laboratory procedure by which anestimate may be made of the extent to which differen
3、t coarseaggregates may polish.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are mathemati-cal conversions to SI units that are provided for informationonly and are not considered standard. Regarding sieves, perSpecification E11, “The val
4、ues stated in SI units shall beconsidered standard for the dimensions of the wire clothopenings and the diameter of the wires used in the wire cloth.”When sieve mesh sizes are referenced, the alternate inch-pounddesignations are provided for information purposes and en-closed in parentheses.1.3 This
5、 standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international
6、standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.
7、2. Referenced Documents2.1 ASTM Standards:2C778 Specification for Standard SandD75 Practice for Sampling AggregatesD1415 Test Method for Rubber PropertyInternationalHardnessD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsE303 Test Method for
8、 Measuring Surface Frictional Proper-ties Using the British Pendulum TesterE501 Specification for Rib Tire for Pavement Skid-Resistance Tests3. Terminology3.1 Definitions:3.1.1 initial friction value (PV-i)the initial British Pendu-lum Tester readings on the test specimens before they arepolished in
9、 the accelerated polishing machine.3.1.2 polish value (PV-n)a measure of the state of polishreached by a test specimen subjected to the specified hours (n)of accelerated polishing using the materials, equipment, andprocedures described in this method. The measurement is madeusing the British pendulu
10、m tester as described in 5.3 and TestMethod E303.3.1.3 residual polish value, (RPV-n)the residual polishvalue is obtained when a constant PV-n is achieved fourconsecutive times with repeated swings of the pendulum.4. Significance and Use4.1 This practice simulates the polishing action of vehiculartr
11、affic on coarse aggregates used in bituminous pavements.4.2 A polish value is determined that may be used to rate orclassify coarse aggregates for their ability to resist polishingunder traffic.NOTE 1The quality of the results produced by this standard aredependant upon the competence of the personn
12、el performing the proce-dure and the capability, calibration, and the maintenance of the equipmentused. Agencies that meet the criteria of Specification D3666 are generallyconsidered capable of competent and objective testing, sampling,inspection, etc. Users of this standard are cautioned that compl
13、iance withSpecification D3666 alone does not completely ensure reliable results.Reliable results depend on many factors: following the suggestions ofSpecification D3666 or similar acceptable guideline provides a means ofevaluating and controlling some of those factors.1This practice is under the jur
14、isdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved June 1, 2017. Published June 2017. Originallyapproved in 1974. Last previous edition approved in 2011 as D3319 11. DOI:10.1520/D3319-11R17.2F
15、or referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C70
16、0, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the Wo
17、rld Trade Organization Technical Barriers to Trade (TBT) Committee.15. Apparatus5.1 Accelerated Polishing Machine3An accelerated pol-ishing machine, also known as the British wheel, and basedupon a 1958 design by the Road Research Laboratory of GreatBritain. This machine shall be mounted on a firm,
18、rigid, andlevel base. The equipment shall include the following:5.1.1 Cylindrical WheelHereafter referred to as the roadwheel, and having a flat-surface periphery and of such size andshape as to permit 14 specimens described below to beclamped onto the periphery to form a continuous surface ofaggreg
19、ate particles, 134 in. (44.45 mm) wide and 16 in.(406.4 mm) in diameter.5.1.2 A means of rotating the road wheel about its own axisat a speed of 320 6 5 rpm.5.1.3 A means of bringing the surface of a rubber-tiredwheel 8 in. (203.2 mm) in diameter and 2 in. (50.8 mm) wideto bear on the aggregate spec
20、imens mounted on the surface ofthe road wheel with a total load of 88 6 1 lbf (391.44 64.45 N). The tire shall be treated, if necessary, to obtain a truerunning surface. The tire shall be free to rotate about its ownaxis, which should be parallel to the axis of the road wheel. Theplane of rotation o
21、f the tire shall coincide with that of the roadwheel. Before a new tire is used on a test, it shall beconditioned by a preliminary run of 6 h with a 150-grit siliconcarbide using dummy specimens (extra or used) on the roadwheel.5.1.3.1 Alternate Tire No. 1An industrial 8 by 2 pneu-matic smooth-tread
22、 hand-truck tire (Note 2). The tire rubberhardness shall be 55 6 5 IRHD measured in accordance withTest Method D1415. The tire shall be inflated to a pressure of45 6 2 psi (310.26 6 13.79 kPa).NOTE 2This is the tire originally supplied with the AcceleratedPolishing Machine3and known by the tire manu
23、facturers designationDunlop RLI 8 by 2. Dunlop discontinued manufacturing of this tire inFebruary 1979. It is retained as an alternate in this practice for those userswho may still have a supply and in the event that Dunlop should resumemanufacturing it in the future.5.1.3.2 Alternate Tire No. 2An i
24、ndustrial 2.80 by 4 (8 in.OD by 4 in. ID), 4 NHS-4 ply, cross-hatch pattern treadhand-truck tire (Notes 3 and 4). The tire shall be inflated to apressure of 35 6 2 psi (241.32 6 13.79 kPa).NOTE 3When it became known that the Dunlop tire (5.1.3.1) was nolonger being manufactured, the necessity of fin
25、ding a replacement tire forthe practice was evident. A search and study by the Texas StateDepartment of Highways and Public Transportation culminated in findingthis tire, a Goodyear Industrial All Weather Hand-Truck tire size 2.80 by4 (Goodyear product code 202-008-002), to give polish values equal
26、tothose obtained with the Dunlop tire.4A suitable inner tube such asGoodyear G250-4 (product code 199-010-700) is necessary. It was alsofound necessary to modify the 4-in. (101.6-mm) wheel furnished with theaccelerated polish machine3to facilitate mounting the Goodyear tire.Approximately 0.10 in. (2
27、.54 mm) should be removed from the wheeldiameter and a larger hole provided for the value stem. This did not affectmounting and use of the Dunlop tire. Goodyear is no longer manufactur-ing this tire.NOTE 4A 1998 study conducted by the Texas Department ofTransportation shows that the use of cross-hat
28、ch tire results in differentialwear of the test specimen surface that mirrors the pattern of the tire. Thisdifferential wear pattern produces falsely higher polish values, particularlyfor softer aggregates. Other research has shown that increased tire wearhas an effect of accentuating the polishing
29、of the test specimens andresulting in lower polish values. Laboratory control specimens should beused to monitor the effect of the tire wear on accelerated polishing andtests results.5.1.3.3 Alternate Tire No. 3An 8-in. (203.2-mm) diametersolid rubber tire (Note 5). The tire rubber hardness shall be
30、 696 3 IRHD measured in accordance with Test Method D1415.It is necessary to move the cylindrical wheel approximately316 in. (4.76 mm) away from the polishing machine to allowthe tire to center over the test specimens. The tire shall bereplaced when the RPV-10 of the control specimens describedin 7.
31、2 have decreased by more than four points from theRPV-10 obtained from a new tire.NOTE 5This is the tire presently supplied by the manufacturer of theaccelerated polishing machine.3Research has shown that increased tirewear has an effect of accentuating the polishing of the test specimens andresulti
32、ng in lower polish values. Laboratory control specimens should beused to monitor the effect of the tire wear on accelerated polishing and testresults.5.1.4 A means to feed the 150-grit silicon carbide abrasiveat the rate given in 8.5. The grit shall be fed continuously andwith a uniform distribution
33、 across the width of the specimens.The grit shall be applied directly onto the road wheel surfaceahead of the point of contact with the rubber-tired wheel.5.1.5 A means to feed the water at the rate given in 8.5 insuch a way that the water is spread continuously and uniformlyover the surface of the
34、road wheel ahead of the point of contactwith the rubber-tired wheel.5.2 Metal MoldsA number of accurately machined metalmolds for preparing specimens. The specimen formed is 3.5 by1.75 by 0.63 in. (88.90 by 44.45 by 16.0 mm) and shall becurved to fit on a surface having an 8-in. (203.2-mm) radius of
35、curvature.5.3 British Pendulum TesterA friction-measuring device.The British pendulum tester used shall conform to Test MethodE303.5.3.1 The slider contact path shall be 3 6116 in. (76.20 61.59 mm).5.3.2 The slider width shall be 114 in. (31.75 mm).5.3.3 The rubber that is bonded to the slider shall
36、 be14 by1by114 in. (6.35 by 25.4 by 31.75 mm).5.3.4 The rubber shall meet the requirements of Specifica-tion E501.5.3.5 The zero adjustment shall be checked before and aftertesting the specimens and as often as the operator deemsnecessary.5.3.6 The calibration procedures of Test Method E303 shallbe
37、used. However, after calibration the small slider shall beinserted.3Available from Wessex Engineering and Metal Craft Co., Ltd., MerchantsBarton, Frome, Somerset, England. If you are aware of alternative suppliers, pleaseprovide this information to ASTM International Headquarters. Your comments will
38、receive careful consideration at a meeting of the responsible technical committee,1which you may attend.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D04-1002. ContactASTM CustomerService at serviceastm.org.D3319 11 (2017)25.3
39、.7 Sanding BlockA rigid metal block with a planedsurface of 7.5-in. (190.5-mm) radius of curvature that isconsistent with the radius of curvature of the road wheelbearing surface.6. Materials and Supplies6.1 WaterA supply of tap water for use where water isrequired for any purpose in this method.6.2
40、 Fine SandA supply of fine sand for sifting into theinterstices of the aggregate prior to placing of the bondingmaterial. Standard sand conforming to Specification C778 hasbeen found suitable for this purpose.6.3 Mold Release AgentThe use of a mold release agent isoptional. A mold release agent may
41、be used to prevent bondingbetween the mold and the bonding material. Silicon releaseagent and paste wax as used for automobiles and floors hasbeen found suitable. The user should use care to prevent thisagent from being absorbed by the aggregate, as it could affectthe measured polish value.6.4 Silic
42、on Carbide GritA supply of silicon carbide grit(150-grit size) to be used as the polishing agent. Grit should bechecked for gradation using Nos. 150-m (No. 100), 106-m(No. 140) and 75-m (No. 200) sieves and separated ifnecessary to maintain a uniform gradation passing the No.150-m (No. 100) sieve an
43、d retained on the No. 75-m (No.200) sieve.6.5 Bonding AgentAsupply of polyester resin and catalyst(or another suitable bonding material, such as an epoxy resin)having a pot life of 20 to 30 min and a curing time of 3 to 6 h.This bonding agent shall not be so fluid as to flow through thefine sand.6.5
44、.1 An optional bonding agent may be used to eliminateuse of the fine sand. This bonding agent must be quite viscousso that it will not flow completely around the aggregateparticles and become part of the surface of the test specimen.Examples of suitable materials are given in Appendix X1.6.5.2 Follo
45、w the manufacturers precautions concerningstorage and use of resin and catalyst.6.6 Coarse AggregateApproximately a12-ft3(0.014-m3)supply of coarse aggregate to be tested and sampled inaccordance with Practice D75. The aggregate shall be normalplant run but laboratory-crushed material may be tested,
46、 if soidentified.7. Test and Control Specimens7.1 Five test specimens for each coarse aggregate shall betested.7.2 Standard laboratory control specimens shall be includedin each run to develop consistency in specimen preparation andpolishing. Four control specimens shall be included with twosets con
47、taining five test specimens each for each run. Aggre-gates used for fabrication of control specimens should be ofconsistent property and RPV-10 test history.NOTE 6It has been found that the polishing surface of controlspecimens can be successfully replicated by filling the bottom of the metalmold wi
48、th a uniform mixture of four parts 2030 grade Ottawa sand andone part polyester resin. The backing of the Ottawa sand controlspecimens should be 100 % polyester resin to facilitate preparation of thesurface bearing against the road wheel.7.3 The aggregate to be tested shall pass the 12.5-mm(12-in) s
49、ieve and shall be retained on a 9.5-mm (38-in.) sieve.NOTE 7Aggregate gradation may be varied to meet the needs of theuser if reported with the test results. However, aggregates larger than12.5 mm (12 in.) may not be accommodated by the mold, and aggregatessmaller than 9.5 mm (38 in.) may not be adequately bonded in thespecimen molding process to be retained for the duration of the test. Forlaboratories and agencies evaluating and monitoring multiple aggregatesources, an alternate aggregate size of passing 9.5-mm (38-in.) sieve
