1、Designation: C 331 05Standard Specification forLightweight Aggregates for Concrete Masonry Units1This standard is issued under the fixed designation C 331; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 specification covers lightweight aggregates i
3、n-tended for use in concrete masonry units when a primeconsideration is to reduce the density of the units.1.2 The values stated in SI units are to be regarded as thestandard. The values shown in parentheses are for informationpurposes only.1.3 The text of this specification references notes andfoot
4、notes which provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C 29/C 29M Test Method for Bulk Density (“Unit Weight”)and Voids in AggregateC40 Test Method fo
5、r Organic Impurities in Fine Aggre-gates for ConcreteC114 Test Methods for Chemical Analysis of HydraulicCementC 136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC 142 Test Method for Clay Lumps and Friable Particles inAggregatesC 151 Test Method for Autoclave Expansion of HydraulicCem
6、entC 157/C 157M Test Method for Length Change of Hard-ened Hydraulic-Cement Mortar and ConcreteC 641 Test Method for Iron Staining Materials in Light-weight Concrete AggregatesC 702 Practice for Reducing Samples of Aggregate toTesting SizeC 1262 Test Method for Evaluating the Freeze-Thaw Dura-bility
7、 of Manufactured Concrete Masonry Units and Re-lated Concrete UnitsD75 Practice for Sampling Aggregates3. Aggregate Types3.1 Three general types of lightweight aggregates are cov-ered by this specification, as follows:3.1.1 Aggregates prepared by expanding, pelletizing, orsintering products such as
8、blast-furnace slag, clay, diatomite,fly ash, shale, or slate, and3.1.2 Aggregates prepared by processing natural materials,such as pumice, scoria, or tuff, and3.1.3 Aggregates consisting of end products of coal or cokecombustion.3.2 The aggregates shall be composed predominately oflightweight-cellul
9、ar and granular inorganic material.4. Chemical Composition4.1 Lightweight aggregates shall not contain excessiveamounts of deleterious substances, as determined by thefollowing limits:4.1.1 Organic Impurities (Test Method C 40)Lightweightaggregates subjected to the test for organic impurities thatpr
10、oduce a color darker than the standard shall be rejected,unless it is demonstrated that the discoloration is due to smallquantities of materials not harmful to the concrete.4.1.2 Staining (Test Method C 641)An aggregate produc-ing a stain index of 60 or higher shall be rejected when thedeposited sta
11、in is found upon chemical analysis to contain aniron content, expressed as Fe2O3equal to or greater than 1.5mg/200 g of sample.4.1.3 Loss on Ignition (Test Methods C 114)Loss onignition of aggregates, consisting of end products of coal orcoke combustion, shall not exceed 12 %. Loss on ignition ofoth
12、er aggregates shall not exceed 5 %.NOTE 1Some aggregates may contain carbonates or water of hydra-tion that contribute to loss on ignition but may not affect the quality of theproduct. Therefore, when evaluating an aggregate, consideration should begiven to the material characteristics that cause th
13、e ignition loss.1This specification is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.21 on Lightweight Aggregates and Concrete.Current edition approved Dec. 15, 2005. Published January 2006. Originallyapproved in 1
14、953. Last previous edition approved in 2004 as C 33104.2For 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.1*A Su
15、mmary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Physical Properties5.1 Lightweight aggregate under test shall meet the follow-ing requirements:5.1.1 Clay Lumps and Friabl
16、e Particles The amount ofclay lumps and friable particles shall not exceed 2 % by drymass.5.1.2 GradingAggregate grading shall be by mutualagreement between interested parties. See Appendix X1 foraggregate grading guidance.5.1.3 Uniformity of GradingTo ensure reasonable unifor-mity in the gradation
17、of successive shipments of lightweightaggregate, fineness modulus shall be determined on samplestaken from shipments at intervals stipulated by the purchaser. Ifthe fineness modulus of the aggregate in any shipment differsby more than 7 % from that of the sample submitted foracceptance tests, the ag
18、gregate in the shipment shall berejected, unless the supplier demonstrated that it will produceconcrete of the required characteristics.5.1.4 Loose Bulk Density (Test Method C 29/C 29M)Theloose bulk density of lightweight aggregates shall conform tothe requirements in Table 1 using a 14 L (12 cubic
19、foot)measure.5.1.5 Uniformity of Loose Bulk Density The dry loosebulk density of lightweight aggregate shipments sampled andtested shall not differ by more than 650 kg/m3(3 lb/ft3)or7%,whichever is greater, from that of the sample submitted foracceptance tests, and shall not exceed the limits in Tab
20、le 1.5.2 Concrete specimens containing lightweight aggregateunder test shall meet the following requirements:5.2.1 PopoutsConcrete specimens prepared and tested inaccordance with 8.1 shall show no surface popouts.5.2.2 Resistance to Freezing and Thawing When re-quired, the aggregate supplier shall d
21、emonstrate by test orproven field performance that the lightweight aggregate whenused in manufactured concrete masonry units and relatedconcrete units has the necessary resistance to freezing andthawing to perform satisfactorily in its intended use.NOTE 2Methods are available to evaluate the perform
22、ance of manu-factured concrete masonry products made with lightweight aggregates.For example, Test Method C 1262 includes procedures for evaluatingmanufactured concrete masonry units and related concrete units, but doesnot include criteria for determining compliance. Care should be used inevaluating
23、 the results of Test Method C 1262 or any other method sincethe results are affected by other characteristics of the concrete mixture inaddition to the characteristics of the lightweight aggregate, including, butnot limited to the following: cement content, cement type, admixtures, andwater content.
24、5.2.3 Drying ShrinkageDrying shrinkage of concretespecimens prepared and tested in accordance with 8.6 shall notexceed 0.10 %.6. Sampling6.1 Sample lightweight aggregates in accordance with Prac-tice D75.6.2 Reduce sample to test sizes in accordance with PracticeC 702.7. Number of Tests7.1 Tests on
25、AggregateOne representative sample is re-quired for each test for organic impurities, staining, clay lumps,loss on ignition, grading, and bulk density.7.2 Tests on Concrete Masonry Units Three specimensare required for the test for popout materials.8. Test Methods8.1 Test for Popout MaterialsObtain
26、test specimens byone of the following methods: (1) Whole concrete masonryunits, free of visible cracks or other structural defects; (2)Portions of concrete masonry units cut from whole units andhaving a surface area of at least 580 cm2(90 in.2); (3)Specimens prepared as described in 8.6. Autoclave t
27、est speci-mens in accordance with Test Method C 151. Visually inspectthe autoclaved specimens for the number of popouts that havedeveloped on the surface and report the average number ofpopouts per specimen.8.2 Test for Resistance to Freezing and ThawingMaketests for resistance to freezing and thawi
28、ng of manufacturedconcrete masonry units and related concrete units in accor-dance with Test Method C 1262.8.3 GradingFollow the procedures of Test Method C 136except that the mass of the test sample for fine aggregate shallbe in accordance with Table 2. The test sample for coarseaggregate shall con
29、sist of 2830 cm3(0.1 ft3) or more of thematerial used for determination of bulk density. Mechanicalsieving of aggregate shall be for 5 min.8.4 Bulk Density (Loose) (Test Method C 29/C 29M)The aggregate shall be tested in an oven-dry condition utilizingthe shoveling procedure.8.5 Clay Lumps and Friab
30、le Particles in Aggregates, shallbe in accordance with Test Method C 142.8.6 Shrinkage of Concrete, shall be in accordance with TestMethod C 157/C 157M, with the following exceptions:TABLE 1 Maximum Bulk Density (Dry Loose) Requirements ofLightweight Aggregates for Concrete Masonry UnitsNominalSize
31、DesignationMaximum DryLoose Bulk Densitykg/m3(lb/ft3)Fine aggregate4.75 mm (No. 4) to 01120 (70)Coarse aggregate9.5to2.36mm(38 in. to No. 8)880 (55)Combined fine and coarse aggregate 1040 (65)TABLE 2 Mass of Sieve Test Sample for Fine LightweightAggregatesNominal Bulk Density (Loose)of AggregateMass
32、 of TestSample, gkg/m3lb/ft380240 515 50240400 1525 100400560 2535 150560720 3545 200720880 4555 2508801040 5565 30010401120 6570 350C3310528.6.1 Prepare a concrete mix in the proportions of one partportland cement to six parts combined aggregates, measured bydry loose volume. Adjust the water conte
33、nt so as to produce aslump of 50 to 75 mm (2 to 3 in.) and thoroughly consolidatethe concrete in steel molds 50 by 50 by 285 mm (2 by 2 by 1114in.). The surface of the concrete shall be steel-troweled.8.6.2 Cure the test specimens in a moist condition for 7 daysat a temperature of 23 6 2 C (73.5 6 3
34、.5 F) and a relativehumidity of not less than 95 %. Make the initial lengthmeasurements immediately after removal of specimens frommoist storage. Store the specimens in an atmosphere of 23 6 2C (73.5 6 3.5 F) and a relative humidity of 50 6 5 % for theduration of the test. Make subsequent measuremen
35、ts at 28 and100 days.8.6.3 Calculate the difference in length of the specimens,when removed from moist storage at an age of 7 days and at thefinal measurement at the age of 100 days, to the nearest 0.01 %of the effective gage length, and report as the drying shrinkageof the specimen. Report the aver
36、age drying shrinkage of thespecimens tested as the drying shrinkage of the concrete.9. Rejection9.1 Material that fails to conform to the requirements of thisspecification shall be subject to rejection. The reason forrejection shall be reported to the producer or supplier promptlyand in writing.10.
37、Certification10.1 When specified in the purchase order or contract, aproducers or suppliers certification shall be furnished to thepurchaser that the material was sampled and tested in accor-dance with this specification and has been found to meet therequirements. When specified in the purchase orde
38、r or contract,a report of the test results shall be furnished.APPENDIX(Nonmandatory Information)X1. AGGREGATE GRADING GUIDE FOR CONCRETE MASONRY UNITS WITH LOWER DENSITIESX1.1 Concrete masonry units with lower densities aremanufactured with lightweight aggregate, with a blend oflightweight aggregate
39、s, or a blend of lightweight and normal-weight aggregates. Because the aggregates being blended maycome from several different sources, the proper combinedaggregate grading (see Fig. X1.1 and Table X1.1) is important,and is one of the essential ingredients in producing qualityconcrete masonry units.
40、 The combined aggregate gradingrange shown optimizes the particle size distribution which, inturn, optimizes the quality of the CMU in the following ways:X1.1.1 Compactibility and high strengths are obtained with-out excessive amounts of cementitious materials.X1.1.2 Shrinkage is reduced by maximizi
41、ng aggregatepacking.X1.1.3 Water absorption and penetration are reduced be-cause of improved compaction.X1.1.4 Resistance to freezing and thawing is improvedbecause better compaction results in fewer interconnectedvoids.X1.2 CommentsX1.2.1 Keep particles retained on the 9.5 mm (38 in.) sieveto a min
42、imum. (“0” is optimum.) (Refer to Letter “A” in Fig.X1.1.)X1.2.2 A uniform, fine textured surface is controlled bylimiting the material on 4.75 mm (No. 4) and 2.36 mm (No. 8)sieves. (Refer to Letter “B” in Fig. X1.1.)FIG. X1.1 Suggested Total Aggregate GradingTABLE X1.1 Suggested Total Aggregate Gra
43、dingSieve SizeAmount Retained On Each Sieve (Volume %)(see Fig. X1.1 andA)9.5mm(38 in.) 0-24.75 mm (No. 4) 0-102.36 mm (No. 8) 15-351.18 mm (No. 16) 15-35600 m (No. 30) 5-20300 m (No. 50) 5-15150 m (No. 100) 5-15Pan 8-20AVolume % and mass % retained on each sieve are essentially equal when thepartic
44、le density of the retained fractions are approximately the same. Volumetricanalysis of particle sizes of blended aggregates composed of aggregates ofdifferent densities is accomplished by considering the proportions of each aggre-gate.C331053X1.2.3 A minimum of 8 % passing the 150 m (No. 100)sieve i
45、s desirable for green strength, moldability and compac-tion. Less than 8 % is acceptable when using mixtures withhigh cementitious material content. (Refer to Letter “C” in Fig.X1.1.)SUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this specification since the last
46、issue,C 33104, which may impact the use of this specification. (Approved December 15, 2005)(1) Revised 5.1.4.Committee C09 has identified the location of selected changes to this specification since the last issue,C 33103a, which may impact the use of this specification. (Approved January 1, 2004)(1
47、) Revised X1.1.(2) Changed “Mass %” to “Volume %” in Fig. X1.1 and TableX1.1.(3) Added footnote to Table X1.1.ASTM 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
48、 that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either rea
49、pproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700,
