1、Designation: C 373 88 (Reapproved 2006)Standard Test Method forWater Absorption, Bulk Density, Apparent Porosity, andApparent Specific Gravity of Fired Whiteware Products1This standard is issued under the fixed designation C 373; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, 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.1. Scope1.1 This test method covers procedures for determiningwater ab
3、sorption, bulk density, apparent porosity, and apparentspecific gravity of fired unglazed whiteware products.1.2 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
4、 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 Measurement of density, porosity, and specific gravity isa tool for determining the degree of maturation of a ceramicbody, or for determining structural properties that may berequ
5、ired for a given application.3. Apparatus and Materials3.1 Balance, of adequate capacity, suitable to weigh accu-rately to 0.01 g.3.2 Oven, capable of maintaining a temperature of 150 65C (302 6 9F).3.3 Wire Loop, Halter, or Basket, capable of supportingspecimens under water for making suspended mas
6、s measure-ments.3.4 ContainerA glass beaker or similar container of suchsize and shape that the sample, when suspended from thebalance by the wire loop, specified in 3.3, is completelyimmersed in water with the sample and the wire loop beingcompletely free of contact with any part of the container.3
7、.5 Pan, in which the specimens may be boiled.3.6 Distilled Water.4. Test Specimens4.1 At least five representative test specimens shall beselected. The specimens shall be unglazed and shall have asmuch of the surface freshly fractured as is practical. Sharpedges or corners shall be removed. The spec
8、imens shall containno cracks. The individual test specimens shall weigh at least 50g.5. Procedure5.1 Dry the test specimens to constant mass (Note 1)byheating in an oven at 150C (302F), followed by cooling in adesiccator. Determine the dry mass, D, to the nearest 0.01 g.NOTE 1The drying of the speci
9、mens to constant mass and thedetermination of their masses may be done either before or after thespecimens have been impregnated with water. Usually the dry mass isdetermined before impregnation. However, if the specimens are friable orevidence indicates that particles have broken loose during the i
10、mpregna-tion, the specimens shall be dried and weighed after the suspended massand the saturated mass have been determined, in accordance with 5.3 and5.4. In this case, the second dry mass shall be used in all appropriatecalculations.5.2 Place the specimens in a pan of distilled water and boilfor 5
11、h, taking care that the specimens are covered with waterat all times. Use setter pins or some similar device to separatethe specimens from the bottom and sides of the pan and fromeach other. After the 5-h boil, allow the specimens to soak foran additional 24 h.5.3 After impregnation of the test spec
12、imens, determine tothe nearest 0.01 g the mass, S, of each specimen whilesuspended in water. Perform the weighing by placing thespecimen in a wire loop, halter, or basket that is suspendedfrom one arm of the balance. Before actually weighing,counterbalance the scale with the loop, halter, or basket
13、inplace and immerse in water to the same depth as is used whenthe specimens are in place. If it is desired to determine only thepercentage of water absorption, omit the suspended massoperation.5.4 After the determination of the suspended mass or afterimpregnation, if the suspended mass is not determ
14、ined, bloteach specimen lightly with a moistened, lint-free linen orcotton cloth to remove all excess water from the surface, anddetermine the saturated mass, M, to the nearest 0.01 g. Performthe blotting operation by rolling the specimen lightly on thewet cloth, which shall previously have been sat
15、urated withwater and then pressed only enough to remove such water aswill drip from the cloth. Excessive blotting will introduce error1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.03 on M
16、ethods for Whitewares and Environmental Concerns.Current edition approved Feb. 15, 2006. Published February 2006. Originallyapproved in 1955. Last previous edition approved in 1999 as C 373 88 (1999).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
17、 United States.by withdrawing water from the pores of the specimen. Makethe weighing immediately after blotting, the whole operationbeing completed as quickly as possible to minimize errorscaused by evaporation of water from the specimen.6. Calculation6.1 In the following calculations, the assumptio
18、n is madethat 1 cm3of water weighs 1 g. This is true within about 3 partsin 1000 for water at room temperature.6.1.1 Calculate the exterior volume, V, in cubic centimetres,as follows:V 5 M 2 S (1)6.1.2 Calculate the volumes of open pores VOPand imper-vious portions VIPin cubic centimetres as follows
19、:VOP5 M 2 D (2)VIP5 D 2 S (3)6.1.3 The apparent porosity, P, expresses, as a percent, therelationship of the volume of the open pores of the specimen toits exterior volume. Calculate the apparent porosity as follows:P 5 M 2 D!/V# 3 100 (4)6.1.4 The water absorption, A, expresses as a percent, therel
20、ationship of the mass of water absorbed to the mass of thedry specimen. Calculate the water absorption as follows:A 5 M 2 D!/D# 3 100 (5)6.1.5 Calculate the apparent specific gravity, T, of thatportion of the test specimen that is impervious to water, asfollows:T 5 D/D 2 S! (6)6.1.6 The bulk density
21、, B, in grams per cubic centimetre, ofa specimen is the quotient of its dry mass divided by theexterior volume, including pores. Calculate the bulk density asfollows:B 5 D/V (7)7. Report7.1 For each property, report the average of the valuesobtained with at least five specimens, and also the individ
22、ualvalues. Where there are pronounced differences among theindividual values, test another lot of five specimens and, inaddition to individual values, report the average of all tendeterminations.8. Precision and Bias8.1 This test method is accurate to 60.2 % water absorptionin interlaboratory testin
23、g when the average value recorded byall laboratories is assumed to be the true water absorption. Theprecision is approximately 60.1 % water absorption on mea-surements made by a single experienced operator.9. Keywords9.1 apparent porosity; apparent specific gravity; bulk den-sity; fired whiteware pr
24、oducts; water absorptionASTM 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 infringe
25、ment 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 reapproved or withdrawn. Your comments are invited either for revision of this standard o
26、r 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 k
27、nown 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, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at 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).C 373 88 (2006)2
