1、Designation:D742815Standard Test Method forResistance of Fine Aggregate to Degradation by Abrasion inthe Micro-Deval Apparatus1This standard is issued under the fixed designation D7428;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,
2、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 a procedure for testing fineaggregate for resistance to abrasion using the Micro-Devala
3、pparatus.1.2 The text of this method references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the test method.1.3 The values stated in SI units are to be regarded asstandard.No other uni
4、ts of measurement are included in thisstandard.1.4 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 determine the applica-bility of regulat
5、ory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C88 Test Method for Soundness of Aggregates by Use ofSodium Sulfate or Magnesium SulfateC117 Test Method for Materials Finer than 75-m(No.200)Sieve in Mineral Aggregates by WashingC136 Test Method for Sieve Analysis of Fine and C
6、oarseAggregatesC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD6928 Test Method for Resistance of Coarse Aggregate toDegradation by Abrasion in the Micro-Deval ApparatusE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Terminology3
7、.1 Definitions:3.1.1 constant mass,nthe condition of a test sample driedat a temperature of 110 6 5C such that it will not lose morethan 0.1%moisture after 2 h of drying.3.1.1.1 DiscussionSuch a condition of dryness can beverified by determining the mass of the sample before and aftersuccessive 2-h
8、drying periods.In lieu of such a determination,samples may be considered to have reached constant masswhen they have been dried at a temperature of 110 6 5C foran equal or longer period than that previously found adequatefor producing the desired constant mass condition under equalor heavier loading
9、 conditions of the oven.4.Summary of Test Method4.1 The Micro-Deval Test is a measure of abrasion resis-tance and durability of mineral aggregates resulting from acombination of actions including abrasion and grinding withsteel balls in the presence of water.A 500-g sample withstandard grading is in
10、itially soaked in water for not less thanone hour.The sample is then placed in a jar mill with 0.75 L ofwater and an abrasive charge consisting of 1250 g of 9.5-mmdiameter steel balls.The jar,aggregate,water,and charge arerevolved at 100 rpm for 15 minutes.The sample is then washedand oven dried.The
11、 loss is the amount of material passing the75 m sieve expressed as a percent by mass of the originalsample.5.Significance and Use5.1 The Micro-Deval abrasion test is a test of fine aggregateto determine abrasion loss in the presence of water and anabrasive charge.Many aggregates are more susceptible
12、 toabrasion when wet than dry,and the use of water in this testincorporates this reduction in resistance to degradation.Thetest results are helpful in evaluating the toughness/abrasionresistance of fine aggregate subject to abrasion when adequateinformation is not available from service records.This
13、 test issuitable for measuring the amount of weak,soft material suchas shale or shaley carbonate in fine aggregate.Materials thatgive a low loss in this test are unlikely to exhibit significantdegradation during handling,mixing or placing.There is arelationship between drying shrinkage of cement mor
14、tar and1This 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 Jan.1,2015.Published February 2015.Originallyapproved in 2008.Last previous edition approved in 2008
15、 as D7428 081.DOI:10.1520/D7428-15.2For 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 International,10
16、0 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Micro-Deval abrasion loss of fine aggregate,with higher lossmaterials resulting in higher drying shrinkage.Descriptions ofthe development of the test and the relationship with otherproperties have been published.3,4,55.2 The Micro-Deval abrasion test on fine aggregate isuseful for detecting changes in properties of aggregate pro-duced from an aggregate source as part of a quality control orquality assurance process.5.
