1、Designation: C181 11 (Reapproved 2018)Standard Test Method forWorkability Index of Fireclay and High-Alumina RefractoryPlastics1This standard is issued under the fixed designation C181; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 test method covers the determination of the work-ability index of fireclay and high-alumina refrac
3、tory plastics bymeasuring the plastic deformation of a molded test specimenwhen subjected to impacts.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 cons
4、idered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitati
5、ons 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 theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Tec
6、hnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2906 Practice for Statements on Precision and Bias forTextiles (Withdrawn 2008)33. Significance and Use3.1 Workability index serves as a measure of the facilitywith which refractory plastic materials can be rammed,gu
7、nned, or vibrated into place.3.2 Workability index is commonly used to control consis-tency of plastics during manufacture. It has also been founduseful for specification acceptance by the consumer.3.3 The workability index determination can provide infor-mation for developing a plastic body. When a
8、 sample splitsunder impact at various water contents, it is an indication thatthe material is “short” or lacking in plasticity.3.4 Determinations on samples that split during impact willbe difficult to reproduce. If the sample splits, the measurementis not a true indication of deformation. This shou
9、ld be noted inthe report.4. Apparatus4.1 RammerThe apparatus shall consist of the deviceknown as the sand rammer for refractories (see Fig. 1). It shallconsist essentially of a steel cylindrical mold (specimen tube)2.00 in. (50.8 mm) in inside diameter and 4.75 in. (120.6 mm)in length, supported in
10、a vertical position on the same axis asa shaft to which shall be fastened a plunger that fits inside themold. A 14-lb (6.4-kg) cylindrical weight slides on the sameshaft and is arranged to fall a distance of 2 in. (51 mm) beforeengaging a collar fastened to the shaft. As shown in Fig. 1, theweight m
11、ay be raised by a manually rotated cam. Provisionshall be made by the equipment manufacturer to support theweight, thereby removing the load from the vertical shaft(example shown in Fig. 2). The sand rammer will include alinear scale capable of measuring sample height to 0.02 in.(0.5 mm) with a typi
12、cal range of 1.7 to 2.5 in. (Note 1). Theportion of the scale to be used shall be adjusted so that whenthe vertical shaft is measuring a 3.00-in. standard, 3.00 in. isread on the scale.NOTE 1The apparatus as described in this section is capable ofmeasuring workabilities up to about 32 %. For product
13、s of higherworkability, a suitable spacer block may be installed under the specimen.4.1.1 Mounting for RammerIt is recommended the ram-mer be mounted on sand rammer base sold by the manufactureror a concrete column to isolate the rammer from vibrationvariations. The rammer is to be secured onto the
14、base orcolumn using steel bolts. Variable results are obtained from thetest unless the described mounting or an acceptable alternativemounting is used for the rammer. An acceptable mounting1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibili
15、ty of Subcommittee C08.09 on Monolith-ics.Current edition approved Oct. 1, 2018. Published October 2018. Originallyapproved in 1943. Last previous edition approved in 2011 as C181 11. DOI:10.1520/C0181-11R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custome
16、r Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
17、t Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Tr
18、ade Organization Technical Barriers to Trade (TBT) Committee.1method is one that can be calibrated using the manufacturerscalibration rings described below in 4.1.2.4.1.2 Maintenance and CalibrationAs needed, dependingon use, clean all moving parts and lubricate with SAE 10 oil.Make periodic checks
19、of the height that the weight drops toensure the weight is being raised 2 in. (51 mm). Inspect therammer to determine whether it and the foundation areproducing full ramming energy. This is accomplished by usingcalibrated impact rings.4Inspect the specimen tube (Note 2).NOTE 2Variation in the smooth
20、ness and dimensions of the specimentube may cause variation in workability values. For referee testing, thespecimen tube may require periodic comparison with a master precisionspecimen tube sold by manufacturer.5. Test Specimens5.1 Temperature of Refractory PlasticSince the workabil-ity index may va
21、ry with a wide spread of temperature, thetemperature of the material to be tested must be between 65and 75 F (18 and 24 C) to reduce this variable. Record thetemperature of material before forming the cylinder.NOTE 3As much as a three-point change in the workability index mayoccur within the 10 F (6
22、 C) stated range.5.2 Number of SpecimensFive cylindrical test specimensshall be molded from the sample of refractory plastic.5.3 Molding of SpecimensThe interior of the mold shall becleaned and coated with a light film of suitable parting agentprior to the preparation of each specimen. To facilitate
23、 fillingthe mold, the sample shall be broken into pieces varying insize, the largest dimension being about 1 in. (25 mm). Thesample weight shall be chosen to provide a sample height of2.5 6 0.1 in. (64 6 3 mm). For a super-duty plastic, the sampleweight is approximately 300 g; for an 85 to 90 % alum
24、ina4Manufacturers calibration rings consist of a set of precision steel rings thatdeform within a specified range to determine full ramming energy; the anvil ispositioned in the specimen tube locating hole in the base of the rammer. A test ringis then placed in the center of the anvil with the axis
25、of the ring being horizontal.The ring is then subjected to three impacts of the rammer head. A measurementacross the center of the deformed ring is then made and compared to the limitsspecified on the box containing the rings. Detailed instructions are included in thecalibration kit.FIG. 1 Apparatus
26、 for Workability Index TestFIG. 2 Example of Provision to Suspend WeightC181 11 (2018)2plastic, approximately 375 g. After placing the material in themold, it shall be subjected to ten impacts by turning the handle,which causes the weight to be raised 2 in. (51 mm) and thendropped upon the collar at
27、tached to the plunger shaft. The moldcontaining the sample shall then be upended and an additionalten impacts given to the specimen. The formed test specimenshall then be extruded from the mold by the use of a suitableauxiliary plunger.6. Procedure6.1 Remove the load on the plunger of the mold bysus
28、pending the weight from the framework in accordance withthe manufacturers instruction. Typically, this is done byslightly rotating the weight while engaging the hooks on thepins (Fig. 2) or engaging the screw head into the slot in theframework. Raise the vertical shaft using raising device (Fig.1),
29、place the test specimen on the bottom of the mold, andlower the shaft until the plunger is in firm contact with thespecimen. Obtain the length of the specimen to the nearest0.02 in. (0.5 mm) by sighting on the rule and the end of theshaft. Disengage the weight from its support and carefullylower it
30、until it is at rest in its normal position. Then apply threeimpacts from the weight to the test specimen. Read the finallength of the specimen from the scale, and record the differencein inches or millimeters between the two measurements.7. Calculation and Report7.1 Calculate the percentage deformat
31、ion for each of thefive test specimens on the basis of the original length and reportthe average value as the workability index. The workabilityindex shall be calculated by the following equation, and shallbe rounded off to one decimal place.W 5L 2 L1L3100where:L = length of specimen prior to deform
32、ation,L1= length of specimen after deformation, andW = workability index.7.2 State the temperature of the sample, the specimenweight used, and whether any test specimen crumbled as aresult of the three impacts.8. Precision and Bias8.1 Interlaboratory Test Data5An interlaboratory test wasrun in 1975,
33、 in which two laboratories each tested ten speci-mens from each of two plastic materials: a super-duty and ahigh-alumina phosphate-bonded plastic. Samples were selectedfrom the same container of plastic and tested in each laboratoryat the same time. The components of variance for workabilityindex re
34、sults calculated by the procedures given in PracticeD2906 are as follows:Within-laboratory component: 4.1 % of the averageBetween-laboratory component: 5.1 % of the average8.2 PrecisionFor the components of variance given in 8.1,two averages of test values should be considered significantlydifferent
35、 at the 95 % probability level if the difference equals orexceeds the critical difference listed as follows (for t = 1.96):Critical Difference, % of Grand Average ofWorkability IndexNumber of Samples inEach AverageWithin-LaboratoryPrecisionBetween-LaboratoryPrecision3 6.6 15.65 5.1 15.010 3.6 14.615
36、 2.9 14.38.3 BiasNo justifiable statement on bias is possible sincethe true value of the workability index cannot be established byan accepted reference material.9. Keywords9.1 refractories; refractory plastic; workabilityASTM International takes no position respecting the validity of any patent rig
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38、 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 International Headquarters. Your comments wi
39、ll receive careful consideration 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 AS
40、TM 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 serviceastm.org (e-mail); o
41、r through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C08-1003. ContactASTM CustomerService at serviceastm.org.C181 11 (2018)3
