1、Designation: C127 15Standard Test Method forRelative Density (Specific Gravity) and Absorption of CoarseAggregate1This standard is issued under the fixed designation C127; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method covers the det
3、ermination of relativedensity (specific gravity) and the absorption of coarse aggre-gates. The relative density (specific gravity), a dimensionlessquantity, is expressed as oven-dry (OD), saturated-surface-dry(SSD), or as apparent relative density (apparent specificgravity). The OD relative density
4、is determined after drying theaggregate. The SSD relative density and absorption are deter-mined after soaking the aggregate in water for a prescribedduration.1.2 This test method is not intended to be used withlightweight aggregates that comply with Specification C332Group I aggregates.1.3 The valu
5、es stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 The text of this test method references notes andfootnotes that provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as
6、 requirements of this test method.1.5 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 limita
7、tions prior to use.2. Referenced Documents2.1 ASTM Standards:2C29/C29M Test Method for Bulk Density (“Unit Weight”)and Voids in AggregateC125 Terminology Relating to Concrete and Concrete Ag-gregatesC128 Test Method for Density, Relative Density (SpecificGravity), and Absorption of Fine AggregateC13
8、6 Test Method for Sieve Analysis of Fine and CoarseAggregatesC330 Specification for Lightweight Aggregates for Struc-tural ConcreteC332 Specification for Lightweight Aggregates for Insulat-ing ConcreteC566 Test Method for Total Evaporable Moisture Content ofAggregate by DryingC670 Practice for Prepa
9、ring Precision and Bias Statementsfor Test Methods for Construction MaterialsC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesD448 Classification for Sizes of Aggregate for Road andBridge ConstructionE11 Specification for Woven Wire Test Sieve Cloth an
10、d TestSieves2.2 AASHTO Standard:AASHTO T 85 Specific Gravity and Absorption of CoarseAggregate33. Terminology3.1 For definition of terms used in this standard, refer toTerminology C125.4. Summary of Test Method4.1 A sample of aggregate is immersed in water for 24 6 4h to essentially fill the pores.
11、It is then removed from the water,the water dried from the surface of the particles, and the massdetermined. Subsequently, the volume of the sample is deter-mined by the displacement of water method. Finally, thesample is oven-dried and the mass determined. Using the mass1This test method is under t
12、he jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregatesand is the direct responsibility of SubcommitteeC09.20 on Normal Weight Aggregates.Current edition approved Jan. 1, 2015. Published March 2015. Originallyapproved in 1936. Last previous edition approved in 2012 as C12712. DOI:10
13、.1520/C0127-15.2For 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.3Available from American Association of State
14、Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1values thus obtained and formulas in this test method,
15、it ispossible to calculate relative density (specific gravity) andabsorption.5. Significance and Use5.1 Relative density (specific gravity) is the ratio of mass ofan aggregate to the mass of a volume of water equal to thevolume of the aggregate particles also referred to as theabsolute volume of the
16、 aggregate. It is also expressed as theratio of the density of the aggregate particles to the density ofwater. Distinction is made between the density of aggregateparticles and the bulk density of aggregates as determined byTest Method C29/C29M, which includes the volume of voidsbetween the particle
17、s of aggregates.5.2 Relative density is used to calculate the volume occu-pied by the aggregate in various mixtures containing aggregate,including hydraulic cement concrete, bituminous concrete, andother mixtures that are proportioned or analyzed on an absolutevolume basis. Relative density (specifi
18、c gravity) is also used inthe computation of voids in aggregate in Test Method C29/C29M. Relative density (specific gravity) (SSD) is used if theaggregate is in a saturated-surface-dry condition, that is, if itsabsorption has been satisfied. Alternatively, the relative density(specific gravity) (OD)
19、 is used for computations when theaggregate is dry or assumed to be dry.5.3 Apparent relative density (specific gravity) pertain to thesolid material making up the constituent particles not includingthe pore space within the particles that is accessible to water.5.4 Absorption values are used to cal
20、culate the change in themass of an aggregate due to water absorbed in the pore spaceswithin the constituent particles, compared to the dry condition,when it is deemed that the aggregate has been in contact withwater long enough to satisfy most of the absorption potential.The laboratory standard for
21、absorption is that obtained aftersubmerging dry aggregate for a prescribed period of time.Aggregates mined from below the water table commonly havea moisture content greater than the absorption determined bythis test method, if used without opportunity to dry prior to use.Conversely, some aggregates
22、 that have not been continuouslymaintained in a moist condition until used are likely to containan amount of absorbed moisture less than the 24-h soakedcondition. For an aggregate that has been in contact with waterand that has free moisture on the particle surfaces, thepercentage of free moisture i
23、s determined by deducting theabsorption from the total moisture content determined by TestMethod C566.5.5 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 s
24、aturation. The values obtained for absorptionby other test methods will be different than the values obtainedby the prescribed soaking, as will the relative density (specificgravity) (SSD).6. Apparatus6.1 BalanceA device for determining mass that issensitive, readable, and accurate to 0.05 % of the
25、sample massat any point within the range used for this test, or 0.5 g,whichever is greater. The balance shall be equipped withsuitable apparatus for suspending the sample container in waterfrom the center of the platform or pan of the balance.6.2 Sample ContainerAwire basket of 3.35 mm (No. 6) orfin
26、er mesh, or a bucket of approximately equal breadth andheight, with a capacity of 4 to 7 L for 37.5-mm (112-in.)nominal maximum size aggregate or smaller, and a largercontainer as needed for testing larger maximum size aggregate.The container shall be constructed so as to prevent trapping airwhen th
27、e container is submerged.6.3 Water TankA watertight tank into which the samplecontainer is placed while suspended below the balance.6.4 SievesA 4.75-mm (No. 4) sieve or other sizes asneeded (see 7.2 7.4), conforming to Specification E11.6.5 OvenAn oven of sufficient size, capable of maintain-ing a u
28、niform temperature of 110 6 5 C (230 6 9 F).7. Sampling7.1 Sample the aggregate in accordance with Practice D75.7.2 Thoroughly mix the sample of aggregate and reduce it tothe approximate quantity needed using the applicable proce-dures in Practice C702. Reject all material passing a 4.75-mm(No. 4) s
29、ieve by dry sieving and thoroughly washing to removedust or other coatings from the surface. If the coarse aggregatecontains a substantial quantity of material finer than the4.75-mm sieve (such as for Size No. 8 and 9 aggregates inClassification D448), use the 2.36-mm (No. 8) sieve in place ofthe 4.
30、75-mm sieve. Alternatively, separate the material finerthan the 4.75-mm sieve and test the finer material according toTest Method C128.NOTE 1If aggregates smaller than 4.75 mm (No. 4) are used in thesample, check to ensure that the size of the openings in the samplecontainer is smaller than the mini
31、mum size aggregate.7.3 The minimum mass of test sample to be used is given asfollows. Testing the coarse aggregate in several size fractions ispermitted. If the sample contains more than 15 % retained onthe 37.5-mm (112-in.) sieve, test the material larger than 37.5mm in one or more size fractions s
32、eparately from the smallersize fractions. When an aggregate is tested in separate sizefractions, the minimum mass of test sample for each fractionshall be the difference between the masses prescribed for themaximum and minimum sizes of the fraction.Nominal Maximum Size,mm (in.)Minimum Mass of TestSa
33、mple, kg (lb)12.5 (12 ) or less 2 (4.4)19.0 (34 ) 3 (6.6)25.0 (1) 4 (8.8)37.5 (112 )51)50 (2) 8 (18)63 (212 ) 12 (26)75 (3) 18 (40)90 (312 ) 25 (55)100 (4) 40 (88)125 (5) 75 (165)7.4 If the sample is tested in two or more size fractions,determine the grading of the sample in accordance with TestMeth
34、od C136, including the sieves used for separating the sizefractions for the determinations in this method. In calculatingC127 152the percentage of material in each size fraction, ignore thequantity of material finer than the 4.75-mm (No. 4) sieve (or2.36-mm (No. 8) sieve when that sieve is used in a
35、ccordancewith 7.2).NOTE 2When testing coarse aggregate of large nominal maximumsize requiring large test samples, it may be more convenient to perform thetest on two or more subsamples, and the values obtained combined for thecomputations described in Section 9.8. Procedure8.1 Dry the test sample in
36、 the oven to constant mass at atemperature of 110 6 5 C, cool in air at room temperature for1 to 3 h for test samples of 37.5-mm (112-in.) nominalmaximum size, or longer for larger sizes until the aggregate hascooled to a temperature that is comfortable to handle (approxi-mately 50 C). Subsequently
37、immerse the aggregate in water atroom temperature for a period of 24 6 4 h. When SpecificationC330 or Specification C332 Group II lightweight aggregatesare used, immerse the aggregate in water at room temperaturefor a period of 72 6 4 h, stirring for at least one minute every24 h.8.2 When the absorp
38、tion and relative density (specificgravity) values are to be used in proportioning concretemixtures in which the aggregates will be in their naturallymoist condition, the requirement in 8.1 for initial drying isoptional, and, if the surfaces of the particles in the sample havebeen kept continuously
39、wet until tested, the requirement in 8.1for 24 6 4hor726 4 h soaking is also optional.NOTE 3Values for absorption and relative density (specific gravity)(SSD) may be significantly higher for aggregate not oven dried beforesoaking than for the same aggregate treated in accordance with 8.1. Thisis esp
40、ecially true of particles larger than 75 mm since the water may notbe able to penetrate the pores to the center of the particle in the prescribedsoaking period.8.3 Remove the test sample from the water and roll it in alarge absorbent cloth until all visible films of water areremoved. Wipe the larger
41、 particles individually. A movingstream of air is permitted to assist in the drying operation. Takecare to avoid evaporation of water from aggregate pores duringthe surface-drying operation. Determine the mass of the testsample in the saturated surface-dry condition. Record this andall subsequent ma
42、sses to the nearest 0.5 g or 0.05 % of thesample mass, whichever is greater.8.4 After determining the mass in air, immediately place thesaturated-surface-dry test sample in the sample container anddetermine its apparent mass in water at 23 6 2.0 C. Take careto remove all entrapped air before determi
43、ning its mass byshaking the container while immersed.NOTE 4The difference between the mass in air and the mass when thesample is submerged in water equals the mass of water displaced by thesample.NOTE 5The container should be immersed to a depth sufficient tocover it and the test sample while determ
44、ining the apparent mass in water.Wire suspending the container should be of the smallest practical size tominimize any possible effects of a variable immersed length.8.5 Dry the test sample in the oven to constant mass at atemperature of 110 6 5 C, cool in air at room temperature 1to 3 h, or until t
45、he aggregate has cooled to a temperature thatis comfortable to handle (approximately 50 C), and determinethe mass.9. Calculations9.1 Relative Density (Specific Gravity):9.1.1 Relative Density (Specific Gravity) (OD)Calculatethe relative density (specific gravity) on the basis of oven-dryaggregate as
46、 follows:Relative density specific gravity!OD! 5 A/B 2 C! (1)where:A = mass of oven-dry test sample in air, g,B = mass of saturated-surface-dry test sample in air, g, andC = apparent mass of saturated test sample in water, g.9.1.2 Relative Density (Specific Gravity) (SSD)Calculatethe relative densit
47、y (specific gravity) on the basis of saturated-surface-dry aggregate as follows:Relative density specific gravity!SSD! 5 B/B 2 C! (2)9.1.3 Apparent Relative Density (Specific Gravity)Calculate the apparent relative density (specific gravity) asfollows:Apparent relative density specific gravity! 5 A/
48、A 2 C! (3)9.2 Average Relative Density (Specific Gravity) ValuesIfthe sample is tested in separate size fractions, compute theaverage values for relative density (specific gravity) of the sizefraction computed in accordance with 9.1 using the followingequation:G 51P1100 G11P2100 G21Pn100 Gnsee Appen
49、dix X1! (4)where:G = average relative density (specific gravity).All forms of expression of relative density(specific gravity) can be averaged in thismanner,G1,G2. Gn= appropriate average relative density (specificgravity) values for each size fraction depend-ing on the type of relative density (specificgravity) being averaged, andP1,P2, . Pn= mass percentages of each size fraction pres-ent in the original sample (not including finermaterialsee 7.4).9.3 AbsorptionCalculate the percentage of absorption, asfollows:Absorption, % 5 B 2 A!/A
