1、Designation: D 5148 97 (Reapproved 2002)Standard Test Method forCentrifuge Kerosine Equivalent1This standard is issued under the fixed designation D 5148; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method determines the centrifuge kerosineequivalent (CKE) of aggregate used in bituminous mixtures.1.2 Units of Measure:1.2
3、.1 With regard to sieve sizes and size of aggregate asdetermined by the use of testing sieves, the values in inch-pound units are shown for the convenience of the user, but thestandard sieve designation shown in parentheses is the standardvalue as stated in Specification E11.1.2.2 With regard to oth
4、er units of measure, the valuesshown in parentheses are for information purposes.1.3 This 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 de
5、termine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see 7.1.2. Referenced Documents2.1 ASTM Standards:C 127 Test Method for Density, Relative Density (SpecificGravity) and Absorption of Coarse Aggregate2C 128 Test Method for Density, Relative Density (Sp
6、ecificGravity) and Absorption of Fine Aggregate2C 702 Practice for Reducing Samples of Aggregate toTesting Size2D75 Practice for Sampling Aggregates3D 4753 Specification for Evaluating, Selecting, and Speci-fying Balances and Scales for Use in Soil, Rock, andConstruction Materials Testing4E11 Specif
7、ication for Wire-Cloth and Sieves for TestingPurposes5E 832 Specification for Laboratory Filter Papers53. Terminology3.1 Symbols:3.1.1 Ccoarse aggregate fraction, that portion of thesample which passes the38-in. (9.5-mm) sieve and is retainedon the No. 4 (4.75-mm) sieve.3.1.2 Ffine aggregate fractio
8、n, that portion of the samplewhich passes the No. 4 (4.75-mm) sieve.3.1.3 SAsurface area.The sum, m2/kg (ft2/lb), obtained byadding the products of the percent passing each sieve and itscorresponding factor, (see 11.1) and dividing by 100.3.1.4 K factorsvalues determined as described in 3.1.5through
9、 3.1.8 and identified as Kc, Kf,orKm.3.1.5 Kcdetermined from the percent of SAE No. 10 oilretained, which represents the total effect of the aggregatesabsorptive properties and surface roughness of the aggregatescoarse fraction.NOTE 1Based on comparative testing in California, the same resultscan be
10、 obtained substituting Shell Tellus No. 100 oil for SAE No. 10 oil.3.1.6 Kfdetermined from the following factors:3.1.7 Percent of kerosine retained, which represents the totaleffect of superficial area, the aggregates absorptive propertiesand surface roughness of the aggregates fine fraction.3.1.7.1
11、 Computed surface area, based on particle size.3.1.7.2 Percent of aggregate passing No. 4 (4.75-mm) sieve.3.1.8 Kmthe “mean” or composite value of K for a givencombination of coarse and fine materials on which Kcand Kfhave already been determined independently.4. Significance and Use4.1 The CKE furn
12、ishes an index, designated as the K factor,that indicates the aggregate particle roughness and surfacecapacity based on porosity.4.2 The CKE is used as part of the Hveem mix designprocedure to determine the approximate bitumen ratio (ABR),as shown in Appendix X1. However, there are other applica-tio
13、ns such as determining the coarse aggregate fraction con-stant (Kc) for use as an aid in selecting a bitumen content foropen-graded friction courses.5. Apparatus5.1 Centrifuge, power driven, capable of exerting a force of400 6 8 times gravity (400 G) on a 100-g sample.1This test method is under the
14、jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved July 10, 2002. Published February 1998. Originallypublished as D 5148 90. Last previous edition D 5148 95.2Annual Book of ASTM Standards,
15、Vol 04.02.3Annual Book of ASTM Standards, Vol 04.03.4Annual Book of ASTM Standards, Vol 04.08.5Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.The required r/min 6 10! of the centrifuge head 5
16、=25.414 000 000/r!where r = radius to center of gravity of sample, mm.5.2 Centrifuge Cups, 71.4 6 1.6 mm (21316 6116 in.) inheight and 52.4 6 1.6 mm (2116 6116 in.) inside diameter (seeFig. 1) complete with perforated brass plate 0.787 6 0.03 mm(0.031 6 0.001 in.) thick with a minimum of 15 holes, 1
17、.575mm 6 0.03 mm (0.0626 0.001 in.) in diameter, per squarecentimetre (100 holes/in.2).5.3 BalanceAbalance having a minimum capacity of 500g and meeting the rquirements of Specification D 4753, ClassGP2.5.4 Metal Funnel, top diameter 98.4 6 1.6 mm (378 6116in.), height 109.5 6 1.6 mm (4516 6116 in.)
18、, orifice 12.7 6 1.6mm (12 6116 in.), with a piece of No. 10 (2.0-mm) sievesoldered slightly above the orifice (Fig. 2).5.5 Tin Pan, round, 114.3 6 1.6 mm (412 6116-in.)diameter, 25.4 6 1.6 mm (16116 in.) deep.6. Materials6.1 Kerosine.6.2 Lubricating Oil, SAE No. 10 (see Note 1).6.3 Filter Paper, si
19、ze 512-cm diameter, Type 1, Class B.NOTE 2VWR Guide No. 613 satisfies ASTM grade Type 1, Class B,Specification E 832.7. Hazards7.1 WarningKerosine is flammable, and therefore cau-tion should be used in storage and use.FIG. 1 Detailed Drawing of a Centrifuge CupFIG. 2 Detailed Drawing for Metal Funne
20、lD 5148 97 (2002)28. Sampling8.1 Sampling is done in accordance with Practice D75.8.2 Reduce the sample in accordance with Practice C 702.9. Preparation of Sample9.1 Determine the bulk specific gravity of the coarse aggre-gate (4.1) and apparent specific gravity of the fine aggregate(4.2), using Tes
21、t Methods C 127 and C 128, respectively.NOTE 3Apparent specific gravity is used for the fine aggregatebecause it is easier to determine than the bulk specific gravity, and its usedoes not affect the CKE results.9.2 Specific GravityCalculate the average specific gravityfor the aggregate based upon th
22、e design grading by thefollowing formula:G 51Pc100Gc1Pf100Gf(1)where:G = average specific gravity,Pc= coarse aggregate present in the original sample,weight %,Pf= fine aggregate present in the original sample, weight%,Gc= bulk (oven dry) specific gravity of the coarse aggre-gate, andGf= apparent spe
23、cific gravity of the fine aggregate.9.3 Separate the aggregate into two size groups, “C” mate-rial (used for Kcdeterminations) passing the38-in. (9.5-mm)sieve and retained on the No. 4 (4.75-mm) sieve, and “F”material (for Kfdetermination) all passing the No. 4 (4.75-mm)sieve.10. Procedures10.1 Proc
24、edure for Fine F:10.1.1 Quarter or split out approximately 105 g for eachsample, representative of the material passing No. 4 (4.75-mm)sieve.10.1.2 Place on hot plate or in 110 6 5C (230 6 9F) ovenand dry to constant weight.10.1.3 Allow to cool.10.1.4 Place 100.0 6 0.1 g in each of the tared centrif
25、ugecups fitted with the perforated metal disk underlying a disk offilter paper.10.1.5 Place centrifuge cups containing samples in pan withsufficient kerosine 12.7 6 3.2 mm (12 618 in.) deep to saturatethe sample. When specimens are thoroughly saturated (bycapillary action), place the cups with sampl
26、es in centrifuge.Samples should be tested in pairs, placed opposite of eachother to avoid damage to the centrifuge.10.1.6 Spin in centrifuge for 2 min at a force of 400 G.10.1.7 Reweigh each cup, containing samples, to nearest 0.1g and subtract original weight. The difference is the percent ofkerosi
27、ne retained (based on 100 g of dry aggregate). Thepercent of kerosine retained is the CKE value. Record theaverage of the two values for duplicate samples.10.2 Procedure for Coarse C:10.2.1 Quarter or split out approximately 105 g for eachsample, representative of the material passing38-in. (9.5-mm)
28、and retained on No. 4 (4.75-mm) sieve material.10.2.2 Dry sample on hot plate or in 110 6 5C (230 6 9F)oven to constant weight and allow to cool to room temperature.10.2.3 Weigh out 100.0 g 6 0.1 g and place in funnel (see5.4).10.2.4 Completely immerse specimen in SAE No. 10 lubri-cating oil for 5 m
29、in (see Note 1).10.2.5 Place the funnel in a container, maintaining the axisin a vertical position and allow to drain for 2 min.10.2.6 Place funnel containing sample in 60C (140F) ovenfor 15 min of additional draining, remembering to keep thefunnel axis in a vertical position.10.2.7 Pour sample from
30、 funnel into tared pan, cool to roomtemperature, and reweigh sample to nearest 0.1 g. Subtractoriginal weight and record difference as percent of oil retained(based on 100 g of dry aggregate).11. Determination of K Factors11.1 Use the following surface area factors to calculatesurface area based upo
31、n design grading as follows:Sieve SizePassed m2/Kg ft2/lbMaximum size 0.41 2No. 4 (4.75 mm) 0.41 2No. 8 (2.36 mm) 0.82 4No. 16 (1.18 mm) 1.6 8No. 30 (600 m) 2.9 14No. 50 (300 m) 6.1 30No. 100 (150 m) 12.3 60No. 200 (75 m) 32.8 16011.1.1 All surface area factors must be used in calculations;thus, if
32、a sample passes No. 4 (4.75-mm) sieve 100 %, includein calculations 100 3 0.41 m2/kg (2 ft2/lb), for passing maxi-mum size as well as 100 3 0.41 m2/kg (2 ft2/lb) for passingNo. 4 (4.75 mm) sieve.11.2 Use the chart shown in Fig. 3 for determination of Kf.11.2.1 If the apparent specific gravity for F
33、is greater than2.70 or less than 2.60, make correction for percent of kerosineretained, using the following formula:Percent of kerosine retained3apparent specific gravity F/2.65!5 CKE corrected for specific gravity(2)11.2.2 Start in lower left hand corner of chart in Fig. 3 withvalue for CKE correct
34、ed for specific gravity, followingstraightedge horizontally to right to the intersection withcalculated surface area, hold point, move vertically upward tothe intersection with the percent passing the No. 4 (4.75-mm)sieve, hold point, and follow straightedge horizontally to right.The value obtained
35、will be the surface constant for the passingNo. 4 (4.75-mm) fraction F and is known as Kf.11.3 Use chart shown in Fig. 4 for determination of Kc.11.3.1 If the bulk (oven dry) specific gravity for C is greaterthan 2.70 or less than 2.60, apply correction to oil retained,using formula at top of chart
36、in Fig. 4.11.3.2 Start at the bottom of chart in Fig. 4 with thecorrected percent of oil retained, follow straightedge verticallyD 5148 97 (2002)3upward to intersection with the diagonal line, hold point, andfollow the straightedge horizontally to the left. The valueobtained will be the surface cons
37、tant for the retained fraction Cand is known as Kc.11.4 Use the chart shown in Fig. 5 to combine Kfand Kcfordetermination of Km.Km5 Kf1 correction to Kf(3)11.4.1 The “correction to Kf” value obtained from Fig. 5 ispositive if (Kc Kf) is positive and is negative if (Kc Kf)isnegative.11.4.2 No correct
38、ion needs to be applied for asphalt viscos-ity.NOTE 4When there is 20 % or less coarse material in a sample, the Kcis not used; therefore, the Kfand Kmare the same.11.4.3 The determination of Kmis shown in the followingexample:Kc5 1.0, Kf5 1.8, SA5 5.12 m2/kg 25 ft2/lb!, passing No. 4 5 60 % (4)11.4
39、.3.1 Using the chart in Fig. 5 start in lower left cornerwith SA = 5.12 m2/kg (25 ft2/lb), follow straightedge horizon-tally to percent of coarse aggregate (40 %), hold point, followstraightedge vertically upward to intersection with the differ-ence between Kcand Kf(0.8), hold point, and follow stra
40、ight-edge horizontally to right to a “correction to Kf.” In thisexample, the correction is 0.2. Because Kc Kf(1.0 1.8) isnegative, the correction is negative; therefore,Km= 1.8 0.2 = 1.6. If Kchad been 1.8, and Kf1.0, Kc Kfwould have been positive ( + 0.8), and the correction (0.2)would have been po
41、sitive. In this case, Kmwould be1.0 + 0.2 = 1.2.12. Report12.1 Report percent kerosine retained, percent oil retained,Kf, Km, and Kc.13. Precision and Bias13.1 Precision:13.1.1 Estimates of variations within a laboratory cannot bemade with available data because in several cases the sameoperator did
42、 not conduct all the tests from which the data weregenerated. However, the following is an estimate of variationbetween laboratories based on a test result that is the averageof two samples.Variation Between LaboratoriesStandardDeviationAcceptable Rangeof Two ResultsKerosine retained, % 0.34 0.962Oi
43、l retained, % 0.416 1.20613.1.2 The precision statement is based on an interlabora-tory study of 19 laboratories that tested two aggregates twicewith an interval of one week. The same operator conducted thefirst series of tests on both aggregates but did not necessarilyconduct the second series of t
44、ests. More specifically, the resultsare based on using an SAE No. 10 oil.13.2 BiasThe procedure in this test method has no biasbecause the values of the kerosine retained and the oil retainedare defined in terms of this test method.FIG. 3 Chart for Determining Kffrom CKEFIG. 4 Chart for Determining
45、Kcfrom Coarse Aggregate PercentOil RetainedD 5148 97 (2002)414. Keywords14.1 aggregates; bitumin content; centrifuge kerosineequivalent; surface roughnessAPPENDIX(Nonmandatory Information)X1.X1.1 ScopeX1.1.1 The Kfand Kcconstants for an aggregate are used inbituminous mix design procedures to determ
46、ine an approxi-mate bitumen ratio (ABR). When used in this manner in theHveem mix design procedure for dense-graded bituminousmixtures, other mix properties are also considered such asappearance (for flushing condition), voids, and Hveem stabilityand cohesion. The ABR calculated for open-graded fric
47、tioncourses from acceptable relations should also be verified byconducting an asphalt drainage test.X1.1.2 The ABR for dense-graded bituminous mixtures isdetermined by use of Fig. X1.1.X1.1.3 Fig. X1.2 is used for correcting the bitumen require-ment for paving asphalts.X1.1.4 The ABR for open-graded
48、 mixtures can be calcu-lated from ABR = 2Kc+ 4.0 and correcting for aggregatespecific gravity.6,76Federal Highway Administration, “Design of Open-Graded Asphalt FrictionCourses,” Report No. FHWA-RD-74-2, January 1974, Washington, DC, Suppl. No.1, July 11, 1975.7White, Thomas D., “Field Performance o
49、f Porous Friction Course,” miscella-neous paper S-76-13, April 1976, US Army Engineer Waterways ExperimentStation, CE, Vicksburg, MS; and Report No. FAA-RD-73-197, February 1975,Federal Aviation Administration, Washington, DC.FIG. 5 Chart for Combining Kfand Kcto Determine KmD 5148 97 (2002)5FIG. X1.1 Chart for Computing Approximate Bitumen Ratio (ABR)for Dense-Graded Bituminous MixturesFIG. X1.2 Chart for Correcting ABR for Grade of AsphaltD 5148 97 (2002)6ASTM International takes no position respecting the validity
