1、Designation: C641 09C641 17Standard Test Method forIron Staining Materials in Lightweight Concrete Aggregates1This standard is issued under the fixed designation C641; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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. Scope*1.1 This test method covers the testin
3、g of lightweight concrete aggregates to evaluate the potential degree of staining from ironcompounds.1.2 The values stated in SI units are to be regarded as the standard. The inch-pound values given in parentheses are providedfor information only.1.3 This standard does not purport to address the saf
4、ety problems associated with its use. It is the responsibility of the user ofthis standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.1.4 This international standard was developed in accordance with internationally recog
5、nized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C125 Terminology Relati
6、ng to Concrete and Concrete AggregatesC330C330/C330M Specification for Lightweight Aggregates for Structural ConcreteC331C331/C331M Specification for Lightweight Aggregates for Concrete Masonry UnitsC702C702/C702M Practice for Reducing Samples of Aggregate to Testing SizeD75D75/D75M Practice for Sam
7、pling AggregatesE11 Specification for Woven Wire Test Sieve Cloth and Test SievesE832 Specification for Laboratory Filter Papers3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, refer to Terminology C125.4. Significance and Use4.1 This test method evaluates the p
8、otential degree of staining attributable to the presence of iron compounds in a lightweightaggregate sample primarily by means of a visual classification method. Such compounds may or may not produce stains on thesurface of the concrete in which the aggregate is incorporated.5. Apparatus5.1 BalanceA
9、 balance or scale accurate to within 0.1 % of the test load at any point within the range of use.5.2 Sieves9.5-mm (38-in.) and 600-m (No. 30) sieves conforming to Specification E11.5.3 Filter Papershall comply with Specification E832 class E2 with a minimum diameter of 250240 mm.1 This test method i
10、s under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee C09.21 onLightweight Aggregates and Concrete.Current edition approved Oct. 1, 2009June 15, 2017. Published November 2009July 2017. Originally approved in 1969. Last prev
11、ious edition approved in 20072009 asC 641 07.C641 09. DOI: 10.1520/C0641-09.10.1520/C0641-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document S
12、ummary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recomme
13、nds that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
14、 West Conshohocken, PA 19428-2959. United States15.4 Cheesecloth WrappingTwo thicknesses, reagent grade cheesecloth, approximately 457 mm (18 in.) square is sufficient forwrapping each sample.5.5 Steam BathAny suitable apparatus that will meet the requirement of the test procedure. Water in the stea
15、m bath, andmakeup water, shall be iron-free water or distilled water.NOTE 1An oven top glassware sterilizer made of nonferrous materials is satisfactory.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents sh
16、all conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.36.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean distilled water or water ofequal purity.6.3 Concentration
17、 of Reagents:6.3.1 Concentrated Acid and Ammonium HydroxideWhen reagents are specified by name it shall be understood thatconcentrated reagents of the following specific gravity are intended:Hydrochloric acid (HCl) sp gr 1.19Ammonium hydroxide (NH4OH) sp gr 0.906.3.2 Diluted acid is described in ter
18、ms of the number of volumes of the concentrated reagent to be added to a given numberof volumes of water. Thus HCl (1 + 2) means 1 volume of HCl (sp gr 1.19) added to 2 volumes of water.7. Sampling7.1 Sample in accordance with Practice D75D75/D75M.7.2 After reducing a field sample to an appropriate
19、size in accordance with Practice C702C702/C702M, thoroughly dry theaggregate and prepare by sieving material to pass the 9.5-mm (38-in.) sieve and is retained on the 600-m (No. 30) sieve.8. Procedure8.1 Select two portions each weighing 100 g from the aggregate sample prepared for test.8.2 Crimp the
20、 edges of two filter papers to form cup-shaped receptacles approximately 130 mm (5 in.) in diameter and 60 mm(212 in.) in depth. Place one of the 100-g portions in each filter cup, spreading to a uniform depth. Fold the sides of the cup tothe center and press in that position.8.3 Wrap both portions
21、of the prepared sample, one on top of the other, in cheesecloth. Saturate with distilled water and exposeto steam in the steam bath for 16 h, h 6 30 min, adding distilled water as make-up water as required.8.4 Remove from the steam bath, and carefully remove the aggregate from the filter papers. Was
22、h both papers in water, placeon a watch glass, and oven dry at a temperature of 110 6 5 C (230 6 9 F). The insoluble products of the decomposition of ironcompounds in the aggregate will be deposited on the filter paper as red, green, or black stains.8.5 Rate the extent of staining on the filter pape
23、rs by the Visual Classification Method.8.5.1 Visual Classification MethodEvaluate the extent and intensity of the stains on the filter paper in accordance with thephotographic stain index reference standards shown in Figs. 1-5: The photographic stain index ranges from No Stain (stain index= 0) to a
24、Very Heavy Stain (stain index = 100).8.6 When required by Specification C330C330/C330M and Specification C331C331/C331M, follow the procedure of theChemical Analysis Method.8.6.1 ChemicalAnalysis MethodThe iron deposits may be dissolved from the filter papers by careful application of HCl froma drop
25、ping bottle and rinsing with hot distilled water from a wash bottle. Otherwise, dissolve the iron compound on the washedand dried filter papers by digesting in HCl (1 + 1) and filtering out the residue of filter pulp washing thoroughly with hot water.Precipitate the iron in the filtrate as ferric hy
26、droxide Fe(OH)3 by adding NH4OH dropwise to neutralize the acid using methyl redindicator solution. Redissolve the Fe(OH)3 precipitate using 10 cm3 of HCl (1 + 1) and determine the iron quantitatively as Fe2O3by standard titration procedures.NOTE 2The iron may be determined by using other standard q
27、uantitative procedures.3 “Reagent Chemicals, American Chemical Society Specifications,” Am. Chemical Soc., Washington, DC. For suggestions on the testing of reagents not listed by theAmerican Chemical Society, see “Reagent Chemicals and Standards,” by Joseph Rosin, D. Van Nostrand Co., Inc., New Yor
28、k, NY, and the “United States Pharmacopeia.”C641 1729. Calculation9.1 Calculate the determined Fe2O3 to the nearest 0.01 mg (to be reported to the nearest 0.1) as follows:Fe2O3,mg/200 g5E3V (1)where:E = Fe2O3 equivalent of standard titration solution, mg/mL,V = millilitres of standard titration solu
29、tion required by the stains from the 200-g sample.Stain Index = 100FIG. 1 Visual Degree of StainingStain Index = 80FIG. 2C641 17310. Report10.1 The report shall include the following:10.1.1 Identification of the sample,10.1.2 Stain index, as evaluated by the Visual Classification Method, when requir
30、ed, and10.1.3 Iron content as milligrams of Fe2O3 per 200 g of sample evaluated by the Chemical Analysis Method.Stain Index = 60FIG. 3Stain Index = 40FIG. 4C641 17411. Precision and Bias11.1 PrecisionThe precision of this test method has not yet been determined, but an interlaboratory testing progra
31、m isunderway. The precision statements will be included when the data are compiled and reviewed.11.2 BiasBias for this test method cannot be determined since there is no reference standard available for comparison.12. Keywords12.1 iron; lightweight aggregate; stainingSUMMARY OF CHANGESCommittee C09
32、has identified the location of selected changes to this test method since the last issue,C641 09C 641 07, that may impact the use of this test method. (Approved October 1, 2009)June 15, 2017.)(1) Revised 4.3.(1) Revised minimum filter paper size in 5.3.(2) Added tolerances to time in 8.3.(3) Added t
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36、o the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at
37、 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ Index = 20FIG. 5C641 175
