ASTM_C_973_-_87_2015.pdf

Designation:C97387(Reapproved 2015)Standard Practice forPreparing Test Specimens From Basic Refractory GunningProducts by Pressing1This standard is issued under the fixed designation C973;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 basic refractory gunning products by pressingprepared material in a mold.After pressing,test specimensprepared from dolomitic mixes are subjected to a prescribedheat treatment.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 on products,for repetitiveevaluations or comparisons of products or product equality,and in specifying a uniform preparation practice for specimensfor acceptance testing.2.3 In using this practice,it must be recognized that thestructure of laboratory-pressed specimens may differ signifi-cantly from the structure of material gunned in field applica-tions.3.Apparatus3.1 Mixer,bench-type,Hobart or equivalent.3.2 Press,mechanical or hydraulic.3.3 Steel Molds.3.4 Furnace.3.5 Oven,air-circulating.3.6 Desiccator.3.7 Trowel.4.Procedure4.1 Store the material to be tested at 85 6 2F(29.5 6 1C)for 24 h prior to testing.Dolomitic materials should be storedin airtight containers.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 3 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 of the desired size should be pressed imme-diately after the batch is mixed.Weigh the proper amount ofmaterial(see 4.4.1)for each specimen to the nearest 0.02 lb(10g),and distribute the mix uniformly in the mold using thenarrow edge of a trowel.(The remainder of the batch should becovered with a damp cloth during the pressing procedure).Press test specimens at 1800 psi(12.41 MPa).4.4.1 Some products contain hydratable materials(forexample,dead-burned dolomite)or quick-setting bonds,orboth,that tend to react during the course of pressing severalspecimens from a single wet-mixed batch.Because of thisreaction,the physical properties of specimens pressed near thebeginning of a batch may differ from those of specimenspressed near the end.Products of these types should be mixedin small batches to minimize this effect.4.5 Test specimens prepared from mixes that do not containdolomite should be air-dried for 4 h,and then dried for a1This 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 C973 87(2009).DOI:10.1520/C0973-87R15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 minimum of 8 h at 225 6 5F(107 6 2.5C)in a circulatingair dryer prior to testing.Testing should be carried out within48 h.4.6 Test specimens prepared from dolomitic mixes requirespecial handling to prevent hydration.Place the test specimensin a furnace at 1830F(1000C)immediately after pressingand soak for a minimum of 2 h.Then remove them from thefurnace before it has cooled below 1100F(593C),cool in airfor a maximum of 2 h,and store in a desiccator or nitrogen-purged box prior to testing.Testing must be performed within48 h,taking precautions to prevent hydration.5.Calculation and Report5.1 In the report on specimen p