1、Designation: C1445 13Standard Test Method forMeasuring Consistency of Castable Refractory Using a FlowTable1This standard is issued under the fixed designation C1445; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 test method covers the procedure for determiningthe consistency of castable refractory mixes by the flow tablemethod.
3、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 C401. They also apply to suchcastables containing metal fibers.1.3 The values stated in inc
4、h-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 is t
5、heresponsibility 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:2C71 Terminology Relating to RefractoriesC230/C230M Specification for Flow Table for U
6、se in Testsof Hydraulic CementC401 Classification of Alumina and Alumina-SilicateCastable RefractoriesC860 Test Method for Determining the Consistency ofRefractory Castable Using the Ball-In-Hand TestD346 Practice for Collection and Preparation of CokeSamples for Laboratory Analysis3. Significance a
7、nd 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 oftest spe
8、cimens 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 water canp
9、roduce “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 C230/C230M) has been found to be an excellent tool for measuringthe consistency of a castable and should be used in
10、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 need to be i
11、n 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 recommendations or to r
12、eproduce the consis-tency of a particular castable between laboratories.3.3 Total time of wet mixing must be closely controlled toobtain reproducible results.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.09 on Mo
13、nolith-ics.Current edition approved Sept. 1, 2013. Published October 2013. Originallyapproved in 1999. Last previous edition approved in 2007 as C1445 07. DOI:10.1520/C1445-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
14、r Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1FIG. 1 Plibrico Ruggedness Test ResultsC1445 1323.4 This test method is
15、 not intended to be used to determinethe proper water content for gunning applications, although itmay provide 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.
16、 All factors were found not to causestatistically significant effects on measured results. See ASTMResearch Report No. C08 1016.4.2 Factors which were found to be rugged during the testmethod evaluation were (1) tamper cross section roundversus rectangular, (2) tamper surface polyurethane sealedvers
17、us 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, 15-lb (6.8-kg) capacity, with sensitivity of0.002 lb (1 g).5.2 Flow Table, Mold, and Calipers, conforming to therequirements of Specification C230/C
18、230M.5.3 TamperA nonabsorbing, nonabrasive, non-brittle ma-terial such as a rubber compound having a Shore 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)
19、 or an equivalent circular cross sectional area and aconvenient length of 5 to 6 in. (127 to 152 mm). 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 man
20、ually or electrically oper-ated (see Fig. 2) mechanical mixer4may be used to preparebatches for the consistency 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
21、below 50 % of the capacity of the mixerbowl because the water required to wet the bowl surfaces changes 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 l
22、east a 1-ft2surface.5.8 Sample Splitter, designed to reduce the castable to thedesired weight and ensure 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 larg
23、est aggregateparticle. If a sample splitter is not available, hand reduction by thecone-and-quarter method may be used. Follow the applicable portions ofthis test method as described in Practice D346.6. Sampling6.1 At the time of use, the dry castable mix should bebetween 68 and 72F (20 and 22C). Th
24、e temperature ismeasured by inserting the full length of the dial-thermometerstem into the material until 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 addition
25、al batchesare required, they should also be reduced to the desired batchsize with a sample splitter.6.3 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
26、Preparation of Castable Sample:7.1.1 Weigh the castable sample (see 6.3) to the nearest0.02 lb (9 g). 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 6
27、8 and 72F (20 and 22C),within12 min. Operate the mixer at 50 to 60 rpm, then addadditional water in small 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 castabl
28、es, 5 min 610 s for insulating castables, and 4 to 6 min for mixes needingheavy vibration, unless specified 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
29、stages of mixing and affect the consistency of the batch.Depending on the aggregate type, particle breakdown may occur with3Laboratory Flow Table Calibration Mixture available from Cement andConcrete Reference Laboratory; Building Research, 226-Room A365; NationalInstitute of Standards and Technolog
30、y; Gaithersburg, MD 208989.4The 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 information to ASTM InternationalHeadquarters. Your comments will rece
31、ive careful consideration at a meeting of theresponsible technical committee,1which you may attend.FIG. 2 Special Mixer for Castable RefractoriesC1445 133excessive mixing time. This was not observed in subcommittee round-robin tests with a 5-min mixing time using a variety of lightweightcastables.7.
32、2 Determination of Flow:7.2.1 For mixes that do not require heavy vibration forforming, such as regular weight and insulating castablerefractories, 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 cent
33、er. Place a layer of castableabout 1 in. (25 mm) in thickness into the mold, and tamp 20times with the tamper. The tamping pressure 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
34、 a plane surface flush with the topof the mold by drawing the straightedge of a trowel (heldnearly perpendicular to the mold) with 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
35、the mold away from the castablewithin 1 min after completing the mixing operation describedin 7.1.1.7.2.2 For castables that require heavy vibration for forming,proceed with flow determination in the following manner:7.2.2.1 Place the mold with large end up on the vibratingtable. Place an excess amo
36、unt 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
37、mold 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 sampl
38、eoff 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 mixin
39、g operationdescribed 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 SpecificationC230/C230M). The flow is the resulting increase in averagebase diameter of the castable mass,
40、 expressed as a percentageof the original base diameter. The special caliper shown in Fig.1 of Specification C230/C230M 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) 100 (%)9. Precision and Bias9.1 The precision of
44、 this test method is based on aninterlaboratory study of ASTM C1445, Standard Test Methodfor Measuring Consistency of Castable Refractory Using aFlow Table, conducted in 2012. Five laboratories participatedin this study. Each of the labs reported three replicate consis-tency results for two differen
45、t cementitious materials. Every“test result” reported represents an individual determination.Except for the use of only five laboratories, Practice E691 wasfollowed for the design and analysis of the data; the details aregiven in ASTM Research Report No. C08-1023.59.1.1 Repeatability (r)The differen
46、ce between repetitiveresults obtained by the same operator in a given laboratoryapplying the same test method with the same apparatus underconstant operating conditions on identical test material withinshort intervals of time would in the long run, in the normal andcorrect operation of the test meth
47、od, exceed the followingvalues only in one case in 20.9.1.1.1 Repeatability can be interpreted as the maximumdifference between two results, obtained under repeatabilityconditions, that is accepted as plausible due to random causesunder normal and correct operation of the test method.9.1.1.2 Repeata
48、bility limits are listed in Table 1 below.TABLE1Flowat5MinutesMaterial AverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitxSrSRrRKerneosStandardCementMortar76.89 6.49 11.25 18.17 31.49KerneosStandardRefractoryCastable96.14 8.94 10.48 25.03 29.
49、35AThe average of the laboratories calculated averages.9.1.2 Reproducibility (R)The difference between twosingle and independent results obtained by different operatorsapplying the same test method in different laboratories usingdifferent apparatus on identical test material would, in the longrun, in the normal and correct operation of the test method,exceed the following values only in one case in 20.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C08-1023. ContactASTM Cu
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