ASTM_C_974_-_87_2015.pdf

Designation:C97487(Reapproved 2015)Standard Practice forPreparing Test Specimens from Basic Refractory CastableProducts by Casting1This standard is issued under the fixed designation C974;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers a procedure for preparing testspecimens from a basic refractory castable by casting preparedmaterial in a mold.Specimens prepared in accordance with thisprocedure are intended for use in ASTM test methods.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Significance and Use2.1 This practice defines a procedure that ensures consistentpreparation of specimens for product testing and evaluation.2.2 This practice can be used in the laboratories ofproducers,users,and general-interest parties for research anddevelopment or quality-control work.It is particularly usefulfor interlaboratory comparisons or products,for repetitiveevaluations or comparisons of products or product quality,andin specifying a uniform preparation practice for specimens foracceptance testing.2.3 In using this practice it must be recognized that thestructure of laboratory-cast specimens may differ significantlyfrom the structure of material cast in field applications.3.Apparatus3.1 Mixer,bench-type,Hobart or equivalent.3.2 Steel Molds.3.3 Vibration Table,spring or air-cushioned,with a pneu-matic or electric driver.23.4 Oven,air circulating.4.Procedure4.1 Store the material to be tested at 85 6 2F(29.5 6 1C)for 24 h prior to testing.4.2 Reduce the sample to the desired batch size with asample splitter or by quartering,taking precautions to preventsegregation.Sufficient material should be batched to provide atleast a 10%excess over test specimen requirements.4.3 Add the weighed,dry batch to the mixer and dry-mix atlow speed for 30 s.Continue to mix at low speed while addingthe required amount of water(see 4.3.1)within 30 s.Wet-mixat low speed for 4 min.4.3.1 Use the amount of water and mixing time(if differentfrom above)recommended by the manufacturer.The watermust be potable and at a temperature of 85 6 2F(29.5 61C).Measure the water addition to the nearest 0.1%byweight.4.4 Specimens should be cast in a mold immediately afterthe batch is mixed so that all specimens made from a batch arecast at the same time.The mold should be securely clamped tothe vibration table top.Fill the mold to overflowing distributingthe material uniformly between each cavity.Vibrate in accor-dance with the manufacturers instructions.Approximately 15s before the end of the vibration period,remove excess material(approximately flush with top of mold).4.4.1 If the batch is too wet,water will run off the specimenswhile if the batch is too dry,the material will not fill the mold.In either case the batch must be discarded and another runmade at a suitable water content.4.5 Test specimens should be air-dried in the molds aminimum of 16 h and a maximum of 24 h,and then removedfrom the molds and dried for a minimum of 8 h at 225 6 5F(107 6 2.5C)in a circulating air dryer prior to testing.1This practice is under the jurisdiction ofASTM Committee C08 on Refractoriesand is the direct responsibility of Subcommittee C08.09 on Monolithics.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1982.Last previous edition approved in 2009 as C974 87(2009).DOI:10.1520/C0974-87R15.2Martin Engineering Model CV35 or Syntron Model VP-80 has been foundsuitable.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Calculation and Report5.1 In the report on specimen preparation,include thepercent water addition,drying time,and test specimen size.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 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 reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Inte