1、Designation: D5821 13 (Reapproved 2017)Standard Test Method forDetermining the Percentage of Fractured Particles in CoarseAggregate1This standard is issued under the fixed designation D5821; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, the 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 test method covers the determination of thepercentage, by mass or by count, of a coarse aggre
3、gate samplethat consists of fractured particles meeting specified require-ments.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are provided for informa-tion only.1.3 This standard does not purport to address all of thesafety concerns, if any, associate
4、d with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recogni
5、zed 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.2. Referenced Documents2.1 ASTM Standards:2C136 Test Method for Si
6、eve Analysis of Fine and CoarseAggregatesC702 Practice for Reducing Samples ofAggregate to TestingSizeD8 Terminology Relating to Materials for Roads and Pave-mentsD75 Practice for Sampling AggregatesE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 Definitions:3.1.1 f
7、ractured face, nan angular, rough, or broken sur-face of an aggregate particle created by crushing, by otherartificial means, or by nature (see Terminology D8).3.1.1.1 DiscussionFor this standard, a face will be con-sidered a “fractured face” only if it has a projected area at leastas large as one-q
8、uarter of the maximum projected area (maxi-mum cross-sectional area) of the particle (this excludes smallnicks, see Fig. 1) and the face has sharp or slightly blunt edges.3.1.2 fractured particle, na particle of aggregate having atleast the minimum number of fractured faces specified (usuallyone or
9、two).4. Significance and Use4.1 Some specifications contain requirements relating topercentage of fractured particles in coarse aggregates. Onepurpose of such requirements is to maximize shear strength byincreasing inter-particle friction in either bound or unboundaggregate mixtures. Another purpose
10、 is to provide stability forsurface treatment aggregates and to provide increased frictionand texture for aggregates used in pavement surface courses.This test method provides a standard procedure for determiningthe acceptability of coarse aggregate with respect to suchrequirements.4.2 Specification
11、s differ as to the number of fractured facesrequired on a fractured particle, and they also differ as towhether percentage by mass or percentage by particle countshall be used. If the specification does not specify, use thecriterion of at least one fractured face and calculate percentageby mass.5. A
12、pparatus5.1 BalanceA balance or scale accurate and readable towithin 0.1 % of the test sample mass at any point within therange of use.5.2 SievesSieves conforming to Specification E11.5.3 SplitterA sample splitter suitable for dividing fieldsamples into test portion sizes in accordance with Practice
13、C702.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved Oct. 1, 2017. Published October 2017. Originallyapproved in 1995. Last previous edition approved in 20
14、13 as D5821 13. DOI:10.1520/D5821-13R17.2For 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 Intern
15、ational, 100 Barr Harbor Drive, PO Box C700, 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, G
16、uides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.4 SpatulaA spatula or similar tool to aid in sortingaggregate particles.6. Sampling6.1 Sample the aggregate in accordance with Practice D75.7. Sample Preparation7.1 Dry the sample sufficie
17、ntly to obtain a clean separationof fine and coarse material in the sieving operation. Sieve thesample over the 4.75-mm (No. 4) sieve, or other specified sievefor retaining material for this test, in accordance with TestMethod C136 and then reduce the portion retained on the sieveusing a splitter in
18、 accordance with Practice C702 to appropriatesize for test.7.2 The mass of the test sample shall be at least largeenough so that the largest particle is not more than 1 % of thesample mass; or the test sample shall be at least as large asindicated below, whichever is smaller:Nominal Maximum SizeSqua
19、reOpenings, mm (in.)Minimum Test SampleMass, g(Approx. lb)9.5 (38) 200 (0.5)12.5 (12) 500 (1)19.0 (34) 1500 (3)25.0 (1) 3000 (6.5)37.5 (112) 7500 (16.5)50.0 (2) 15 000 (33)63.0 (212) 30 000 (66)75.0 (3) 60 000 (132)90.0 (312) 90 000 (198)7.3 For aggregate with a nominal maximum size of 19.0 mm(34 in
20、.) or larger, where the fracture particle content is to bedetermined for material retained on the 4.75-mm (No. 4) orsmaller sieve, the test sample may be separated on the 9.5-mm(38-in.) sieve. The portion passing the 9.5-mm (38-in.) sievemay then be further reduced, in accordance with Practice C702,
21、to a minimum of 200 g (0.5 lb). This will reduce the number ofparticles to be separated during the procedure. In this case,percent fractured particles is determined on each portion, and aweighted average percentage of fractured particles is calculatedbased on the mass of each of the portions to refl
22、ect the totalpercentage of fractured particles in the entire sample.8. Procedure8.1 Wash the sample over the sieve designated for determi-nation of fractured particles to remove any remaining finematerial, and dry to constant mass. Determine the mass of thetest sample, and any subsequent determinati
23、ons of mass, to thenearest 0.1 % of the original dry sample mass.8.2 Spread the dried test sample on a clean, flat surface largeenough to permit careful inspection of each particle. To verifythat a particle meets the fracture criteria, hold the aggregateparticle so that the face is viewed directly.
24、If the faceconstitutes at least one-quarter of the maximum cross-sectionalarea of the rock particle, consider it a fractured face.8.3 Using the spatula or similar tool, separate into twocategories: (1) fractured particles based on whether the particlehas the required number of fractured faces, and (
25、2) particles notmeeting the specified criteria. Use Figs. 2-7 to aid in thisdetermination. Be aware that some of the particles in Figs. 2-4do show more than one fractured face. If the required numberof fractured faces is not given in the applicable specifications,the determination will be made on th
26、e basis of a minimum ofone fractured face.8.4 Determine the mass or count of particles in the fracturedparticle category and the mass or count of the particles notmeeting the specified fracture criteria. Use mass to calculatepercent fractured particles unless percentage by particle countis specified
27、.8.5 If more than one number of fractured faces is specified(for example, 70 % with one or more fractured faces and 40 %with two or more fractured faces), repeat the procedure on thesame sample for each requirement.9. Report9.1 Report the mass percentage or count percentage ofparticles with the spec
28、ified number(s) of fractured faces to thenearest 1 % in accordance with the following:P 5 F/F1N!# 3100 (1)FIG. 1 Schematic of a Fractured Particle with One Fractured FaceD5821 13 (2017)2where:P = percentage of particles with the specified number offractured faces,F = mass or count of fractured parti
29、cles with at least thespecified number of fractured faces, andN = mass or count of particles in the non-fractured categorynot meeting the fractured particle criteria.9.2 Report the specified fracture criteria against which thesample was evaluated.9.3 Report the total mass in grams of the coarse aggr
30、egatesample tested.9.4 Report the sieve on which the test sample was retainedat the start of the test.9.5 Report whether the percentage of fractured particles wasdetermined by mass or by particle count.10. Precision and Bias10.1 PrecisionThe Ontario Ministry of Transportationreported that in a forma
31、l study of 34 well-trained observers oftwo samples of partly fractured gravel (proportion of fracturedparticles = 76 %) the average standard deviation was found tobe 5.2 %. Therefore, the difference in results between twowell-trained observers, on samples of the same material, shouldnot exceed 14.7
32、% of their average, 19 times in 20.NOTE 1When a mixture of trained and untrained observers conductedthis test, the average multi-operator standard deviation increased to about7.6 %.FIG. 2 Fractured Particle (Sharp Edges, Rough Surfaces)FIG. 3 Fractured Particle (Sharp Edges, Smooth Surfaces)D5821 13
33、 (2017)310.2 BiasThis test method has no bias because the valuesdetermined can be defined only in terms of the test method.11. Keywords11.1 aggregate; crushed aggregate; crushed gravel; crushedparticles; fractured faces; fractured particlesFIG. 4 a) Fractured Particle (Round Edges, Rough Surfaces)FI
34、G. 4 b) Fractured Particle (Round Edges, Rough Surfaces) (continued)FIG. 4 c) Fractured Particle (Round Edges, Rough Surfaces) (continued)D5821 13 (2017)4FIG. 5 Fractured Particle (Center) Flanked by Two Non-Fractured Particles (Chipped Only)FIG. 6 Non-Fractured Particle (Round Edges, Smooth Surface
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38、o the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at
39、 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 7 Non-Fractured Particle (Rounded Particles, Smooth Surfaces)D5821 13 (2017)6
