1、Designation: C 1445 07Standard Test Method forMeasuring Consistency of Castable Refractory Using a FlowTable1This standard is issued under the fixed designation C 1445; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st 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 the procedure for determiningthe consistency of castable refractory mixes by the flow tablemeth
3、od.1.2 This test method applies to regular weight castablerefractories, insulating castable refractories, and castable re-fractories that require heavy vibration for forming, which aredescribed in Classification C 401. They also apply to suchcastables containing metal fibers.1.3 The values stated in
4、 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.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
5、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. Referenced Documents2.1 ASTM Standards:2C 71 Terminology Relating to RefractoriesC 230/C 230M Specification for FlowTable
6、 for Use inTestsof Hydraulic CementC 401 Classification of Alumina and Alumina-SilicateCastable RefractoriesC 860 Practice for Determining the Consistency of Refrac-tory Castable Using the Ball-In-Hand TestD 346 Practice for Collection and Preparation of CokeSamples for Laboratory Analysis3. Signifi
7、cance and Use3.1 The amount of water used in a castable mix forpreparing test specimens has a significant influence on subse-quent test results. This test method is used primarily todetermine and reproduce the consistency required for theoptimum casting of refractory castables in the preparation oft
8、est specimens and to express that consistency quantitatively.The correct water content is one of the major factors that mustbe controlled to obtain uniform test specimens. Excess watercan reduce strength, increase volume shrinkage, and promotesegregation of the castable ingredients. Insufficient wat
9、er canproduce “honeycombs” (air voids) in the castable because ofpoor consolidation during placement and prevent completehydration of cement.3.2 The flow table (see sketches in Specification C 230/C 230M) has been found to be an excellent tool for measuringthe consistency of a castable and should be
10、 used in cases wherea numerical result is required. Since castables differ somewhatin their “body” or plasticity, it has been found that a goodcasting range, expressed numerically, might vary from castableto castable. While one material may cast well between 40 and60 % flow, another material may nee
11、d to be in the 60 to 80 %flow range to properly flow. Because of this, it has been foundthat no arbitrary optimum range can be stated for all castables.The flow table then becomes a tool for measuring the flow andnot determining it. It can allow the operator to follow themanufacturers recommendation
12、s or to reproduce the consis-tency of a particular castable between laboratories.3.3 Total time of wet mixing must be closely controlled toobtain reproducible results.3.4 This test method is not intended to be used to determinethe proper water content for gunning applications, although itmay provide
13、 information of value for interpretation by a skilledoperator.4. Interferences (Factors Known to Affect Results)4.1 A ruggedness test (Fig. 1) was performed using “C230Calibration Mixture”3. All factors were found not to causestatistically significant effects on measured results. See ASTMResearch Re
14、port No. C08 1016.4.2 Factors which were found to be rugged during the testmethod evaluation were (1) tamper cross section round1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.09 on Monolith-ics.Current edition app
15、roved March 1, 2007. Published April 2007. Originallyapproved in 1999. Last previous edition approved in 2005 as C 1445 99(2005).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
16、on, refer to the standards Document Summary page onthe ASTM website.3Laboratory Flow Table Calibration Mixture available from Cement andConcrete Reference Laboratory; Building Research, 226-Room A365; NationalInstitute of Standards and Technology; Gaithersburg, MD 208989.1Copyright ASTM Internationa
17、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.versus rectangular, (2) tamper surface polyurethane sealedversus unsealed, (3) mold filling procedure, (4) number oftamps 36 versus 44, (5) table drop time 7 s versus 11 s, and(6) operator.5. Apparatus5.1 Balance,
18、 15-lb (6.8-kg) capacity, with sensitivity of0.002 lb (1 g).FIG. 1 Plibrico Ruggedness Test ResultsC14450725.2 Flow Table, Mold, and Calipers, conforming to therequirements of Specification C 230/C 230M.5.3 TamperA nonabsorbing, nonabrasive, non-brittle ma-terial such as a rubber compound having a S
19、hore A durometerhardness of 80 6 10 or hardwood dowel made nonabsorbingby coating with either solvent or water based polyurethane, andthe tamper shall have a cross section of12 by 1 in. (13 by 25mm) or an equivalent circular cross sectional area and aconvenient length of 5 to 6 in. (127 to 152 mm).
20、The tampingface shall be flat and at right angles to the length of the tamper.5.4 Trowel, having a steel blade 4 to 6 in. (100 to 150 mm)in length, with straight edges.5.5 Castable MixerEither a manually or electrically op-erated (see Fig. 2) mechanical mixer4may be used to preparebatches for the co
21、nsistency determination. Size the mixingbowl to contain 50 to 70 % volume loading with the dry batch.NOTE 1Castable-water requirement variation becomes more signifi-cant as dry volume loadings drop below 50 % of the capacity of the mixerbowl because the water required to wet the bowl surfaces change
22、s morerapidly with decreasing volume loadings.5.6 Thermometer, dial or digital-type, metal, with a rangefrom 0 to 180F (18 to 80C).5.7 Vibrating TableAn electric vibrating table with3600 Hz and at least a 1-ft2surface.5.8 Sample Splitter, designed to reduce the castable to thedesired weight and ensu
23、re that the grain size distribution isrepresentative of the original batch.NOTE 2A Jones or riffle-type sample splitter is satisfactory, providedthe openings are large enough to accommodate the largest aggregateparticle. If a sample splitter is not available, hand reduction by thecone-and-quarter me
24、thod may be used. Follow the applicable portions ofthis test method as described in Practice D 346.6. Sampling6.1 At the time of use, the dry castable mix should bebetween 68 and 72F (20 and 22C). The temperature ismeasured by inserting the full length of the dial-thermometerstem into the material u
25、ntil the reading is constant.6.2 Reduce the mass of the castable mix with a samplesplitter to obtain the desired batch size in accordance with 6.3.Take precautions to prevent segregation. If additional batchesare required, they should also be reduced to the desired batchsize with a sample splitter.6
26、.3 Batch sizes for the flow table test normally consist of10 lb (4.5 kg) for a regular weight or 5 lb (2.3 kg) for aninsulating castable. Mixer size may dictate other sizes. (See5.5).7. Procedure7.1 Preparation of Castable Sample:7.1.1 Weigh the castable sample (see 6.3) to the nearest0.02 lb (9 g).
27、 Place the batch in the mixer described in 5.5 (seeNote 1), and dry mix for 1 min. While the mixer is operatingat slow speed, add 90 % of the estimated water requirementhaving a temperature between 68 and 72F (20 and 22C),within12 min. Operate the mixer at 50 to 60 rpm, then addadditional water in s
28、mall amounts from a tared container, andmix until the batch appears to have the desired flow.7.1.2 The total actual wet mixing time, including wateradditions, should be 3 min 6 10 s for dense castables, 5 min 610 s for insulating castables, and 4 to 6 min for mixes needingheavy vibration, unless spe
29、cified differently by the manufac-turer.NOTE 3Mixing times of less than 5 min for insulating castables mayinfluence the results because lightweight aggregates usually soak up waterduring the initial stages of mixing and affect the consistency of the batch.Depending on the aggregate type, particle br
30、eakdown may occur withexcessive mixing time. This was not observed in subcommittee round-robin tests with a 5-min mixing time using a variety of lightweightcastables.7.2 Determination of Flow:7.2.1 For mixes that do not require heavy vibration forforming, such as regular weight and insulating castab
31、le refrac-tories, proceed with flow determination in the followingmanner:7.2.1.1 Carefully wipe the flow-table top until clean and dry,and place the flow mold at the center. Place a layer of castableabout 1 in. (25 mm) in thickness into the mold, and tamp 20times with the tamper. The tamping pressur
32、e should be justsufficient to ensure uniform filling of the mold. Fill the moldwith additional castable, and tamp as specified for the firstlayer. Cut off the castable to a plane surface flush with the topof the mold by drawing the straightedge of a trowel (heldnearly perpendicular to the mold) with
33、 a sawing motion, acrossthe top of the mold. Wipe the table top around the mold untilclean and dry. Carefully remove any water from around theedge of the flow mold. Lift the mold away from the castablewithin 1 min after completing the mixing operation describedin 7.1.1.7.2.2 For castables that requi
34、re heavy vibration for forming,proceed with flow determination in the following manner:4The sole source of supply of mechanical mixers known to the committee at thistime is Hobart Corporation, 701 S. Ridge Ave., Troy, OH 45374. If you are awareof alternative suppliers, please provide this informatio
35、n to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.FIG. 2 Special Mixer for Castable RefractoriesC14450737.2.2.1 Place the mold with large end up on the vibratingtable. Place an excess amount
36、of castable into the mold. Turnon the vibrating table while holding the sample mold firmly onthe table.Vibrate the sample until all the large air bubbles ceaseevolving from the castable and the castable fills out the mold.Cease vibration. Scrape off the excess castable above the upperrim of the mold
37、 with a straightedge trowel. Vibrate the sampleagain until its upper surface is smooth and even with the upperrim of the sample mold. The total vibration time should be nomore than 30 s. Rotate the sample mold on the vibrating tableso that the sample will not adhere to the table. Slide the sampleoff
38、 the vibrating table and place it, inverted, onto the center ofa clean, dry flow table. Lift the mold vertically from the tablewhile pressing down upon the castable sample so that minimaldeformation of the sample occurs. Lift the mold away from thecastable within 1 min after completing the mixing op
39、erationdescribed in 7.1.1.7.2.3 Immediately drop the table 15 times in9saheight of12 in. (13 mm). This distance is automatically controlled by acam in a properly constructed flow table (see SpecificationC 230/C 230M). The flow is the resulting increase in averagebase diameter of the castable mass, e
40、xpressed as a percentageof the original base diameter. The special caliper shown in Fig.1 of Specification C 230/C 230M is graduated to indicate onefourth of the actual flow so that the readings of four measure-ments may be added to give the flow value, eliminatingcalculations of the average of four
41、 individual measurements.Using the special caliper, make four measurements of the basediameter of the castable mass at equivalently spaced intervals.Sum the four measurements to obtain the percent flow.7.2.4 In reproducing a consistency within a specified flowrange, it may be necessary to make sever
42、al trial mixes withvarying percentages of water. Make each trial with a freshbatch.8. Report8.1 Report the following information:8.1.1 The type of mixer used to prepare the test batch.8.1.2 The amount of water used in each batch (% by wt. drycastable).8.1.3 The total mixing time (minutes).8.1.4 The
43、dry mix temperature, F (C).8.1.5 The water temperature, F (C).8.1.6 The percent flow directly from the sum of the specialcalipers, or calculated as follows if using standard calipers:(average base diameter original base diameter/originalbase diameter) 3 100 (%)9. Precision and Bias9.1 PrecisionThe r
44、epeatability standard deviation hasbeen determined to be 1.71 on a refractory castable having angrand average flow of 31.15 %.5The reproducibility standarddeviation from the same testing was 0.24. The combinedrepeatability and reproducibility standard deviation was 1.73.NOTE 4This information was ba
45、sed upon a Gauge Repeatability andReproducibility study performed by North American Refractories Com-pany using multiple trials and multiple operators, but only one flow table.Additional precision testing between laboratories must be conducted onthis test method.9.2 BiasWhile a standard reference ma
46、terial now existswhich could be used for interlaboratory testing of bias,3thiswork has not yet been completed.10. Keywords10.1 castable; concrete; consistency; flow; flow-table; mix-ing; refractoryASTM International takes no position respecting the validity of any patent rights asserted in connectio
47、n 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
48、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 International Headquarters. Your comments will receive careful consid
49、eration 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 known 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 servic
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