ASTM C674-2018 pdf free download

ASTM C674-2018 pdf free download.Standard Test Methods for Flexural Properties of Ceramic Whiteware Materials
1. Scope
1.1 These test methods cover determination of the modulus of rupture and the modulus of elasticity of fired ceramic whitewares bodies, formed by any fabrication method, and are applicable to both glazed and unglazed test specimens. 1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Apparatus
4.1 Testing Machine—Any suitable testing machine may be used, provided uniform rates of direct loading can be main- tained. 4.1.1 For all specimens the loading rate should be such that the specimen should fail in approximately 1 min. Table 1 lists loading rates that shall be used for each size specimen. For strengths of specimens intermediate of those specified, inter- polation can be used to obtain the equivalent loading rate. 4.1.2 For the prescribed rectangular specimens the loading rate shall be 1000 6 150 lbs (454 6 68 kg)/min. 4.2 Bearing Edges—For the support of the test specimen, two steel (or high-strength ceramic) knife edges rounded to a radius of 0.125 in. (3.18 mm) shall be provided. The load shall be applied by means of a third steel knife edge rounded to a radius of 0.125 in. When testing rectangular specimens, the supporting members for the bearing edges shall be constructed to provide a means for alignment of the bearing surfaces with the surfaces of the test specimen (it being possible that the rectangular specimen may be wedge-shaped or twisted). The apparatus shown in Figs. 1 and 2 are suggested as suitable devices for ensuring proper spacing and alignment of the bearing edges for rectangular test specimens.
5. Test Specimens
5.1 Preparation of Specimens—Form, fire, and finish the specimens by the appropriate methods, following practices used in actual production. 5.2 Dimensions—The specimens shall be approximately 1.125 in. (28.6 mm), 0.750 in. (19.2 mm), 0.500 in. (12.7 mm), or 0.250 in. (6.4 mm) in diameter, whichever diameter is most comparable to that of the finished product. The length shall be 6 6 0.50 in. (153 6 12.7 mm) to permit an overhang ofat least 0.25 in. (6.4 mm) at each end when mounted on the supports. Note that the 0.25-in. specimens may be 3.75 6 0.25 in. (95 6 7 mm) long. 5.2.1 The dry-pressed specimens shall be rectangular bars approximately 1 in. (25.4 mm) by 0.50 in. (12.7 mm) in cross section and at least 4.50 in. (114 mm) in length to permit an overhang of at least 0.25 in. at each end when mounted on the supports. 5.3 Handling—Observe all due precautions in the forming, drying, and firing to produce straight test specimens ofuniform cross section. 5.4 Storage—Cool test specimens taken warm from the kiln in a desiccator. If the testing must be delayed, store the bars in the desiccator, or in an electric oven at 110°C, and then cool in a desiccator before testing. When removing specimens from a hot kiln, take care to avoid thermal shock which will lead to erroneous results.