1、Designation: C 637 98a (Reapproved 2003)Standard Specification forAggregates for Radiation-Shielding Concrete1This standard is issued under the fixed designation C 637; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st 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. Scope1.1 This specification covers special aggr
3、egates for use inradiation-shielding concretes in which composition or highspecific gravity, or both, are of prime consideration.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 The following precautionary caveat pertain
4、s only to thetest method portion, Section 8, of this specification:Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicabi
5、lity of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2C 33 Specification for Concrete AggregatesC 127 Test Method for Density, Relative Density (SpecificGravity) and Absorption of Coarse AggregateC 128 Test Method for Density, Relative Density, (SpecificGravity) and
6、 Absorption of Fine AggregateC 131 Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in the LosAngeles MachineC 136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC 535 Test Method for Resistance to Degradation of Large-Size Coarse Aggregate
7、by Abrasion and Impact in the LosAngeles MachineC 638 Descriptive Nomenclature of Constituents of Aggre-gates for Radiation-Shielding Concrete3. Classification3.1 Aggregates covered by this specification include:3.1.1 Natural mineral aggregates of either high density orhigh fixed water content, or b
8、oth. These include aggregates thatcontain or consist predominately of materials such as barite,magnetite, hematite, ilmenite, and serpentine.3.1.2 Synthetic aggregates such as iron, steel, ferrophospho-rus and boron frit or other boron compounds (see DescriptiveNomenclature C 638).3.1.3 Fine aggrega
9、te consisting of natural or manufacturedsand including high-density minerals. Coarse aggregate mayconsist of crushed ore, crushed stone, or synthetic products, orcombinations or mixtures thereof.4. Composition and Specific Gravity4.1 Table 1 gives data on chemical composition and specificgravity of
10、aggregate materials covered by this specification.4.2 The purchaser shall specify the minimum specific grav-ity for each size and type of aggregate.4.2.1 Uniformity of Specific GravityThe bulk specificgravity (saturated surface-dry) of successive shipments ofaggregate shall not differ by more than 3
11、 % from that of thesample submitted for source approval tests. The averagespecific gravity of the total shipment shall be equal to or greaterthan the specified minimum.4.3 The purchaser shall specify the minimum fixed watercontent of hydrous ores. If the design temperature, T, isdifferent from that
12、given in 8.1.3.5, the purchaser shall specifythe value of T.4.3.1 Uniformity of Fixed Water ContentFor hydrousaggregates the fixed water content of successive shipments ofaggregate shall not be less than 95 % of the specified minimumvalue. The average fixed water content of the total shipmentshall b
13、e equal to or exceed the specified minimum value.5. Aggregate Grading5.1 Sieve AnalysisFine and coarse aggregates for conven-tionally placed concrete shall be graded within the limits givenin Specification C 33, except that with the approval of thepurchaser, as much as 20 % of the material passing t
14、he 9.5-mm(38 -in.) sieve may also pass the 150-m (No. 100) sieve, with1This specification is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.41 on Concrete for Radiation Shielding.Current edition approved May 10, 199
15、8. Published December 1998. Originallyapproved in 1969. Last previous edition approved in 1998 as C 637 98a.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 stan
16、dards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.up to 10 % passing the 75-m (No. 200) sieve if the materialpassing the 75-m (No. 200) sieve is essentially free of clay orshale.5.1.1 Fine
17、 and coarse aggregates for preplaced aggregateconcrete shall be graded according to the requirements of Table2 and as follows:Grading of AggregateSpecific Gravityof Fine AggregateCoarseAggregateFineAggregateUp to 3.0 Grading 1 Grading 1Greater than 3.0 Grading 1 Grading 2Full range Grading 2 Grading
18、 25.1.2 When boron frit is used as part of the fine aggregate,the grading shall be such that 100 % passes the 4.75-mm (No.4) sieve and not more than 5 % passes the 600-m (No. 30)sieve.5.2 Fineness ModulusIf the fineness modulus of the fineaggregate varies more than 0.2 from the value corresponding t
19、othat of the sample submitted for acceptance, the fine aggregateshall be rejected unless suitable adjustments are made inconcrete proportions to compensate for the difference ingrading.6. Deleterious Substances6.1 Fine and coarse aggregates shall meet the requirementsof Specification C 33.6.2 Boron
20、frit shall not contain more than 2.0 % of watersoluble material.NOTE 1This limit is based on concrete mixtures containing no morethan 300 kg/m3(500 lb/yd3) of boron frit.7. Abrasion Resistance of Coarse Aggregate7.1 Coarse aggregate shall have an abrasion loss not greaterthan 50 % when tested in acc
21、ordance with Test Method C 131,or Test Method C 535, as applicable. Coarse aggregate failingto meet this requirement may be used, provided it can beshown that it produces satisfactory strengths in concrete of theproportions selected for the work.8. Methods of Sampling and Testing8.1 Sample and test
22、the aggregates in accordance with themethods cited in Specification C 33 as applicable, except asfollows:8.1.1 Specific GravityDetermine the bulk specific gravity(saturated surface-dry basis) of fine aggregate in accordancewith Test Method C 128, and of coarse aggregate in accordancewith Test Method
23、 C 127, except that the weight of the testsample for fine and coarse aggregate shall be approximately thespecified weight multiplied by the ratio:specific gravity of aggregate/2.65using for specific gravity the higher value given in Table 1.8.1.2 Grading Method C 136, except that the weight ofthe te
24、st sample for fine and coarse aggregate shall be approxi-mately the specified weight multiplied by the ratio:TABLE 1 Composition and Specilc Gravity of Aggregates Covered by This SpeciflcationPredominantConstituentClass of MaterialChemical Composition ofPrincipal ConstituentASpecific Gravity ofAvail
25、ableAggregatesSerpentineBcrushed stone, hydrous siliente Mg3Si2O5(OH)42.4 to 2.65LimoniteCcrushed stone, hydrous iron ore (HFeO2)x(H2O)y3.4 to 3.8GoethiteCcrushed stone, hydrous iron ore HFeO23.5 to 4.5Barite gravel or crushed stone BaSO44.0 to 4.4Ilmenite crushed stone, iron ore FeTiO34.2 to 4.8Hem
26、atite crushed stone, iron ore Fe2O34.6 to 5.2Magnetite crushed stone, iron ore FeFe2O44.6 to 5.2Iron manufactured from iron/steel Fe 6.5 to 7.5FerrophosphorousDsynthetic FenP 5.8 to 6.3Boron FritEsynthetic B2O3,Al2O3, SiO2, CaO 2.6 to 2.8Boron Carbide synthetic B4C, B2O3, C 2.5Calcium Boride synthet
27、ic CaB6, C 2.5AWhen it is necessary to minimize the production of long-lived secondary radiation in the shield, or to avoid using materials having inherent radioactivity, the purchasershould specify limits on the contents of objectionable elements.BThe fixed water content of serpentine ranges from 1
28、0 to 13 percent by weight.CThe fixed water content of limonite and goethite ranges from 8 to 12 percent by weight.DFerrophosphorus when used in Portland cement concrete will generate flammable and possibly toxic gases which can develop high pressures if confined. SeeClendenning, T. G., Kellam, B., a
29、nd MacInnis, C., “Hydrogen Evolution from Ferrophosphorous Aggregate in Portland Cement Concrete,” Journal of the American ConcreteInstitute, No. 12, December 1968. (Proceedings, Vol 65, pp. 10211028), and Mather, Bryant, discussion of Davis, Harold S., “Concrete for Radiation ShieldingInPerspective
30、,” and closure by author in “Concrete for Nuclear Reactors,” Journal of the American Concrete Institute SP-34, Vol 1, 1972, pp. 1113.EThe fixed water content of boron frit is less than 0.5 %.TABLE 2 Grading Requirements for Coarse and Fine Aggregatesfor Preplaced Aggregate ConcreteSieve SizePercenta
31、ge PassingGrading 1For 37.5-mm (112 -in.)Nominal Maximum Size AggregateGrading 2For 25-mm (1-in.) NominalMaximum SizeAggregateCoarse Aggregate50-mm (2-in.) 100 . . .37.5-mm (112 in.) 95 to 100 10025.0-mm (1-in.) 40 to 80 95 to 10019.0-mm (34 in.) 20 to 45 40 to 8012.5-mm (12-in.) 0 to 10 0 to 159.5-
32、mm (38-in.) 0 to 2 0 to 2Fine Aggregate2.36-mm (No. 8) 100 . . .1.18-mm (No. 16) 95 to 100 100600-m (No. 30) 55 to 80 75 to 95300-m (No. 50) 30 to 55 45 to 65150-m (No. 100) 10 to 30 20 to 4075-m (No. 200) 0 to 10 0 to 10Fineness modulus 1.30 to 2.10 1.00 to 1.60C 637 98a (2003)2specific gravity of
33、aggregate/2.65using for specific gravity the higher value given in Table 1.8.1.3 Fixed Water ContentWhen 90 % or more of theweight loss on ignition of the aggregate is due to fixed watercontent, determine the fixed water content, F, by the loss-on-ignition test according to 8.1.3.1. When less than 9
34、0 % of theloss on ignition is due to fixed water content, determine thefixed water content by the train method (8.1.3.2). In case ofdispute, use results obtained by the train method as the basisfor acceptance or rejection of the aggregate. Use the trainmethod to demonstrate that 90 % or more of the
35、weight lostduring ignition is fixed water. When loss-on-ignition tests arebeing made on aggregate samples from the same source, alsodetermine the fixed water content of the first sample and eachtenth sample thereafter by the train method.8.1.3.1 For the loss-on-ignition test crush a representativesa
36、mple of aggregate weighing 20 to 50 g (W) to pass the4.75-mm (No. 4) sieve. Heat the sample to constant weight ata temperature, T, in a furnace, open to the atmosphere. Cool theheated sample in a desiccator and then weigh it, (Wt). Place thesample in the oven again, heat at the ignition temperature,
37、 t,cool in a desiccator, and determine the final weight (Wt).Constant weight may be considered to have been attained whenfurther heating at the design temperature T causes or wouldcause less than 0.1 % additional weight loss.8.1.3.2 In the train test, heat approximately 1 g (W8) of thefinely ground
38、sample to constant weight (W8T) at a temperatureof T. Then heat the sample W8Tin a stream of argon gas at theignition temperature t. Pass water vapor and gaseous materialdriven from the heated sample through magnesium perchlorate.The gain in weight (W8g) of the magnesium perchlorate is anindication
39、of the fixed water content of the sample at tempera-ture T. Also determine the dehydrated weight (W8t) of thesample at the ignition temperature t.8.1.3.3 Compute the fixed water content at temperature T byone of the following equations:Ignition Test:F, percent5WT2Wt!/WT#3100 (1)where:WT= sample heat
40、ed to constant weight, g, andWt= heated and cooled sample, g.Train Test:F, percent5W8g2W8T!3100 (2)where:W8g= gain in weight of sample, g, andW8T= dehydrated weight, g.8.1.3.4 Determine the percent of nonhydrous volatile mate-rial, V, as follows:Train Test:V, percent5$W82W8t1W8g!#/W8T%3100 (3)where:
41、W8 = sample weight, g,W8t= dehydrated weight of sample, g,W8g= gain in weight of sample, g, andW8T= sample heated to constant weight, g.8.1.3.5 Water vapor driven from the sample by heating attemperature T is considered as part of the nonhydrous volatilematerial. Absorbed water at 110C is not consid
42、ered as part ofthe nonhydrous volatile material. Determine percent absorptionby Test Methods C 127 and C 128.8.1.3.6 Temperature values shall be as follows:DesignTemperature, TIgnitionTemperature, tHydrous Aggregate F C F CIron ore 230 110 932 500Serpentine 572 300 1652 900Heat the sample until it r
43、eaches constant weight at thespecified temperature, unless otherwise approved. Determineweights after sample has been cooled in a desiccator to roomtemperature. Duplicate determinations of fixed water contentshould check to within 0.3 %.8.1.4 Water-Soluble Material in Boron FritPlace a 5.00-gsample
44、passing a 600-m (No. 30) sieve and retained on a300-m (No. 50) sieve in contact with 100 mL of distilledwater at 20 6 5C for 16 h. Filter, wash with about 200-mL ofhot (70 6 5C) water, and dry at 125 6 10C for 1 h. Weighthe residue, s, to the nearest 0.01 g. Calculate the percentage ofwater soluble
45、material (Ws) to the nearest 0.1 % as follows:W355.002s!/s3100where:s=residue, g9. Precision and Bias9.1 Precision The following precision statement ad-dresses the test of the water-soluble material in Boron Frit. Theprecision for fixed water content by either the loss on ignitiontest or by the trai
46、n test method has not been evaluated.9.1.1 Data from one laboratory was available for estimatingthe precision of water-soluble material in boron frit, therefore,only a within-laboratory estimate of precision is made. Theestimate is based on 15 replicate analyses of 5 lots of fritproduced by one comp
47、any. The 15 replicates were determinedon 5 separate days, 3 replicates per day. The mean watersoluble material ranged from 1.23 to 1.75 % among the 5 lots.9.1.2 Within-laboratory PrecisionThe within-laboratorystandard deviation among individual determinations of water-soluble material in boron frit
48、is 0.224 %.3Therefore, twoanalyses of the same material should differ by no more than0.627 %3in 95 % of cases.9.2 BiasSince there is no accepted reference materialsuitable for determining the bias of this test method, nostatement on bias is made.3These numbers represent, respectively, the 1s and d2s
49、 limits as described inPractice C 670.C 637 98a (2003)310. Keywords10.1 aggregates; boron frit; calcium boride; high-densityaggregates; high water-content aggregates; hydrous aggre-gates; radiation shielding concreteASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own re
