1、Designation: C 128 07aStandard Test Method forDensity, Relative Density (Specific Gravity), and Absorptionof Fine Aggregate1This standard is issued under the fixed designation C 128; 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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method covers
3、 the determination of the averagedensity of a quantity of fine aggregate particles (not includingthe volume of voids between the particles), the relative density(specific gravity), and the absorption of the fine aggregate.Depending on the procedure used, the density, in kg/m3(lb/ft3)is expressed as
4、oven-dry (OD), saturated-surface-dry (SSD), oras apparent density. Likewise, relative density (specific grav-ity), a dimensionless quality, is expressed as OD, SSD, or asapparent relative density (apparent specific gravity). The ODdensity and OD relative density are determined after drying theaggreg
5、ate. The SSD density, SSD relative density, and absorp-tion are determined after soaking the aggregate in water for aprescribed duration.1.2 This test method is used to determine the density of theessentially solid portion of a large number of aggregateparticles and provides an average value represe
6、nting thesample. Distinction is made between the density of aggregateparticles as determined by this test method, and the bulkdensity of aggregates as determined by Test Method C 29/C 29M, which includes the volume of voids between theparticles of aggregates.1.3 This test method is not intended to b
7、e used for light-weight aggregates.1.4 The values stated in SI units are to be regarded as thestandard for conducting the tests. The test results for densityshall be reported in either SI units or inch-pound units, asappropriate for the use to be made of the results.1.5 The text of this test method
8、references notes andfootnotes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of this test method.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It i
9、s 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:2C 29/C 29M Test Method for Bulk Density (“Unit Weight”)and Voids in AggregateC70 T
10、est Method for Surface Moisture in Fine AggregateC117 Test Method for Materials Finer than 75-m (No.200) Sieve in Mineral Aggregates by WashingC 125 Terminology Relating to Concrete and ConcreteAggregatesC 127 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Coarse Aggr
11、egateC 188 Test Method for Density of Hydraulic CementC 566 Test Method for Total Evaporable Moisture Contentof Aggregate by DryingC 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC 702 Practice for Reducing Samples of Aggregate toTesting SizeD75 P
12、ractice for Sampling AggregatesD 854 Test Methods for Specific Gravity of Soil Solids byWater Pycnometer2.2 AASHTO Standard:AASHTO No. T 84 Specific Gravity andAbsorption of FineAggregates33. Terminology3.1 Definitions:3.1.1 absorption, nthe increase in mass of aggregate dueto water penetrating into
13、 the pores of the particles, during a1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.20 on Normal Weight Aggregates.Current edition approved Aug. 1, 2007. Published September 2007. Originallyappr
14、oved in 1936. Last previous edition approved in 2007 as C 12807.2For 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 websi
15、te.3Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive,
16、PO Box C700, West Conshohocken, PA 19428-2959, United States.prescribed period of time but not including water adhering tothe outside surface of the particles, expressed as percentage ofthe dry mass.3.1.2 density, nthe mass per unit volume of a material,expressed as kilograms per cubic metre (pounds
17、 per cubicfoot).3.1.2.1 density (OD), nthe mass of oven-dry aggregateparticles per unit volume of aggregate particles, including thevolume of permeable and impermeable pores within particles,but not including the voids between the particles.3.1.2.2 density (SSD), nthe mass of saturated-surface-dryag
18、gregate per unit volume of the aggregate particles, includingthe volume of impermeable pores and permeable, water-filledpores within the particles, but not including the voids betweenthe particles.3.1.2.3 apparent density, nthe mass per unit volume of theimpermeable portion of the aggregate particle
19、s.3.1.3 oven-dry (OD), adjrelated to aggregate particles,the condition in which the aggregates have been dried byheating in an oven at 110 6 5 C for sufficient time to reach aconstant mass.3.1.4 relative density (specific gravity), nthe ratio of thedensity of a material to the density of water at a
20、statedtemperature; the values are dimensionless.3.1.4.1 relative density (specific gravity), (OD), nthe ratioof the density (OD) of the aggregate to the density of water ata stated temperature.3.1.4.2 relative density (specific gravity), (SSD), nTheratio of the density (SSD) of the aggregate to the
21、density ofwater at a stated temperature.3.1.4.3 apparent relative density (apparent specific gravity),nthe ratio of the apparent density of aggregate to the densityof water at a stated temperature.3.1.5 saturated-surface-dry (SSD), adjrelated to aggre-gate particles, the condition in which the perme
22、able pores ofaggregate particles are filled with water to the extent achievedby submerging in water for the prescribed period of time, butwithout free water on the surface of the particles.3.1.6 For definitions of other terms related to aggregates seeTerminology C 125.4. Summary of Test Method4.1 A
23、sample of aggregate is immersed in water for 24 6 4h to essentially fill the pores. It is then removed from the water,the water is dried from the surface of the particles, and themass determined. Subsequently, the sample (or a portion of it)is placed in a graduated container and the volume of the sa
24、mpleis determined by the gravimetric or volumetric method. Finally,the sample is oven-dried and the mass determined again. Usingthe mass values thus obtained and formulas in this test method,it is possible to calculate density, relative density (specificgravity), and absorption.5. Significance and U
25、se5.1 Relative density (specific gravity) is the characteristicgenerally used for calculation of the volume occupied by theaggregate in various mixtures containing aggregate includingportland cement concrete, bituminous concrete, and othermixtures that are proportioned or analyzed on an absolutevolu
26、me basis. Relative density (specific gravity) is also used inthe computation of voids in aggregate in Test Method C 29/C 29M. Relative density (specific gravity) (SSD) is used in thedetermination of surface moisture on fine aggregate by dis-placement of water in Test Method C70. Relative density(spe
27、cific gravity) (SSD) is used if the aggregate is wet, that is,if its absorption has been satisfied. Conversely, the density orrelative density (specific gravity) (OD) is used for computa-tions when the aggregate is dry or assumed to be dry.5.2 Apparent density and apparent relative density (apparent
28、specific gravity) pertain to the solid material making up theconstituent particles not including the pore space within theparticles that is accessible to water. This value is not widelyused in construction aggregate technology.5.3 Absorption values are used to calculate the change in themass of an a
29、ggregate material due to water absorbed in the porespaces within the constituent particles, compared to the drycondition, when it is deemed that the aggregate has been incontact with water long enough to satisfy most of the absorp-tion potential. The laboratory standard for absorption is thatobtaine
30、d after submerging dry aggregate for a prescribedperiod of time. Aggregates mined from below the water tablecommonly have a moisture content greater than the absorptiondetermined by this test method, if used without opportunity todry prior to use. Conversely, some aggregates which have notbeen conti
31、nuously maintained in a moist condition until usedare likely to contain an amount of absorbed moisture less thanthe 24-h soaked condition. For an aggregate that has been incontact with water and that has free moisture on the particlesurfaces, the percentage of free moisture is determined bydeducting
32、 the absorption from the total moisture contentdetermined by Test Method C 566 by drying.5.4 The general procedures described in this test method aresuitable for determining the absorption of aggregates that havehad conditioning other than the 24-h soak, such as boilingwater or vacuum saturation. Th
33、e values obtained for absorptionby other test methods will be different than the values obtainedby the prescribed 24-h soak, as will the density (SSD) orrelative density (specific gravity (SSD).5.5 The pores in lightweight aggregates are not necessarilyfilled with water after immersion for 24 h. In
34、fact, theabsorption potential for many such aggregates is not satisfiedafter several days immersion in water. Therefore, this testmethod is not intended for use with lightweight aggregate.6. Apparatus6.1 BalanceA balance or scale having a capacity of 1 kgor more, sensitive to 0.1 g or less, and accu
35、rate within 0.1 % ofthe test load at any point within the range of use for this testmethod. Within any 100-g range of test load, a differencebetween readings shall be accurate within 0.1 g.6.2 Pycnometer (for Use with Gravimetric Procedure)Aflask or other suitable container into which the fine aggre
36、gatetest sample can be readily introduced and in which the volumecontent can be reproduced within 6 0.1 cm3. The volume ofthe container filled to mark shall be at least 50 % greater thanC 128 07a2the space required to accommodate the test sample. A volu-metric flask of 500-cm3capacity or a fruit jar
37、 fitted with apycnometer top is satisfactory for a 500-g test sample of mostfine aggregates.6.3 Flask (for Use with Volumetric Procedure)A LeChatelier flask as described in Test Method C 188 is satisfac-tory for an approximately 55-g test sample.6.4 Mold and Tamper for Surface Moisture TestThe metal
38、mold shall be in the form of a frustum of a cone withdimensions as follows: 40 6 3-mm inside diameter at the top,906 3-mm inside diameter at the bottom, and 75 6 3mminheight, with the metal having a minimum thickness of 0.8 mm.The metal tamper shall have a mass of 340 6 15 g and a flatcircular tampi
39、ng face 25 6 3 mm in diameter.6.5 OvenAn oven of sufficient size, capable of maintain-ing a uniform temperature of 110 6 5 C (230 6 9 F).7. Sampling7.1 Sample the aggregate in accordance with Practice D75.Thoroughly mix the sample and reduce it to obtain a testspecimen of approximately 1 kg using th
40、e applicable proce-dures described in Practice C 702.8. Preparation of Test Specimen8.1 Place the test specimen in a suitable pan or vessel anddry in the oven to constant mass at a temperature of 110 6 5C (230 6 9 F). Allow it to cool to comfortable handlingtemperature (approximately 50 C), cover wi
41、th water, either byimmersion or by the addition of at least 6 % moisture to thefine aggregate, and permit to stand for 24 6 4h.8.1.1 Where the absorption and relative density (specificgravity) values are to be used in proportioning concretemixtures in which the aggregates will be in their naturallym
42、oist condition, the requirement in 8.1 for initial drying isoptional, and, if the surfaces of the particles in the sample havebeen kept continuously wet until tested, the requirement in 8.1for 24 6 4 h soaking is also optional.NOTE 1Values for absorption and for relative density (specific grav-ity)
43、(SSD) may be significantly higher for aggregate not oven dried beforesoaking than for the same aggregate treated in accordance with 8.1.8.2 Decant excess water with care to avoid loss of fines (seealso Appendix X1), spread the sample on a flat nonabsorbentsurface exposed to a gently moving current o
44、f warm air, andstir frequently to secure homogeneous drying. Employ me-chanical aids such as tumbling or stirring to assist in achievingthe saturated surface-dry condition, if desired. Continue thisoperation until the test specimen approaches a free-flowingcondition. Follow the procedure in 8.3 to d
45、etermine if surfacemoisture is still present on the constituent fine aggregateparticles. Make the first trial for surface moisture when there isstill some surface water in the test specimen. Continue dryingwith constant stirring and test at frequent intervals until the testindicates that the specime
46、n has reached a surface-dry condi-tion. If the first trial of the surface moisture test indicates thatmoisture is not present on the surface, it has been dried past thesaturated surface-dry condition. In this case, thoroughly mix afew millilitres of water with the fine aggregate and permit thespecim
47、en to stand in a covered container for 30 min. Thenresume the process of drying and testing at frequent intervalsfor the onset of the surface-dry condition.8.3 Test for Surface MoistureHold the mold firmly on asmooth nonabsorbent surface with the large diameter down.Place a portion of the partially
48、dried fine aggregate loosely inthe mold by filling it to overflowing and heaping additionalmaterial above the top of the mold by holding it with thecupped fingers of the hand holding the mold. Lightly tamp thefine aggregate into the mold with 25 light drops of the tamper.Start each drop approximatel
49、y 5 mm above the top surface ofthe fine aggregate. Permit the tamper to fall freely undergravitational attraction on each drop. Adjust the starting heightto the new surface elevation after each drop and distribute thedrops over the surface. Remove loose sand from the base andlift the mold vertically. If surface moisture is still present, thefine aggregate will retain the molded shape. Slight slumping ofthe molded fine aggregate indicates that it has reached asurface-dry condition.8.3.1 Some fine aggregate with predominately angular-shaped particles or with a
