TM_D_3398_
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Designation:D 3398 00Standard Test Method forIndex of Aggregate Particle Shape and Texture1This standard is issued under the fixed designation D 3398;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the particleindex of aggregate as an overall measure of particle shape andtexture characteristics.1.2 The values stated in inch-pound units are to be regardedas the standard.The SI units given in parentheses may beapproximate,except with regard to sieve size and size ofaggregate,the standard SI designations shown in parenthesesare the standard as stated in Specification E 11.1.3 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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:C 127 Test Method for Specific Gravity and Absorption ofCoarse Aggregate2C 128 Test Method for Specific Gravity and Absorption ofFine Aggregate2C 136 Test Method for Sieve Analysis of Fine and CoarseAggregates2C 702 Practice for Reducing Field Samples of Aggregate toTesting Size2D 75 Practice for Sampling Aggregates3D 1883 Test Method for Bearing Ratio of Laboratory-Compacted Soils4D 3665 Practice for Random Sampling of ConstructionMaterials3D 4753 Specification for Evaluating,Selecting,and Speci-fying Balances and Scales for Use in Testing Soil,Rock,and Related Construction Materials4E 11 Specification for Wire-Cloth and Sieves for TestingPurposes53.Significance and Use3.1 This test method provides an index value to the relativeparticle shape and texture characteristics of aggregates.Thisvalue is a quantitative measure of the aggregate shape andtexture characteristics that may affect the performance of roadand paving mixtures.This test method has been successfullyused to indicate the effects of these characteristics on thecompaction and strength characteristics of soil-aggregate andasphalt concrete mixtures.6,7,8,94.Apparatus4.1 Cylindrical MoldsCylindrical molds for determiningvoids in aggregate,in accordance with the procedure describedin this test method,shall be machined to accurate dimensionson the inside,and sufficiently rigid to retain their forms underrough usage.The dimensions of the molds shall conform to thelimits in Table 1.4.2 Tamping RodsRound,straight,steel tamping rods,having the tamping end rounded to a hemispherical tip,shall beenclosed in a loose-fitting steel sleeve as shown in Fig.1,tocontrol the height of drop to exactly 2 in.(50 mm).Thedimensions and mass of the tamping rods shall conform to thelimits in Table 2.4.3 BalanceA balance having a minimum capacity of 15kg and meeting the requirements of Specification D 4753,Class GP5.5.Sampling5.1 Sample the aggregate to be tested in accordance withPractices D 75 and D 3665,and reduce to the appropriate testsample size in accordance with Practice C 702.6.Calibration of Mold6.1 Determine the volume of the mold in millilitres asdescribed below at least two times,and use the average volume1This test method is under the jurisdiction of ASTM Committee D04 on Roadsand Paving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved July 10,2000.Published September 2000.Originallypublished as D 3398 75.Last previous edition D 3398 97.2Annual Book of ASTM Standards,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 14.02.6Huang,E.Y.,“A Test for Evaluating the Geometric Characteristics of CoarseAggregate Particles,”ASTM Proceedings,Vol 62,1962,pp.12231242.7Huang,E.Y.,Auer,A.,and Triffo,R.P.,“Effect of Geometric Characteristicsof CoarseAggregates on Strength of Soil-Aggregate Mixtures,”ASTM Proceedings,Vol 64,1964,pp.922933.8McLeod,Norman W.,and McLean,J.A.,“A Laboratory Investigation of theCompaction of Dense Graded Asphalt Concrete,”paper presented at the 19thAnnual Conference of the Canadian Technical Asphalt Association,ReginaSaskatchewan,Canada,1974.9McLeod,Norman W.,and Davidson,J.Keith,“Particle Index Evaluation ofAggregate Paving Mixtures,”Proceedings,Association of Asphalt Paving Tech-nologies,Vol 50,1981,pp.251290.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.in the calculation of the percentage of voids in 8.2.6.1.1 Fill the mold with water at room temperature andcover with a piece of plate glass in such a way as to eliminatebubbles and excess water.6.1.2 Determine the mass of water in the mold to anaccuracy of 4 g or less.6.1.3 Meas