1、Designation: C 181 09Standard Test Method forWorkability Index of Fireclay and High-Alumina PlasticRefractories1This standard is issued under the fixed designation C 181; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、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 plastic refractoriesb
3、y measuring the plastic deformation of a molded test speci-men when 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 considered stand
4、ard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenc
5、ed Documents2.1 ASTM Standards:2D 2906 Practice for Statements on Precision and Bias forTextiles3. Significance and Use3.1 Workability index serves as a measure of the facilitywith which plastic refractory materials can be rammed,gunned, or vibrated into place.3.2 Workability index is commonly used
6、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 sample splitsunder impact at various water contents, it is an indic
7、ation 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 should be noted inthe report.4. Apparatus4.1 RammerThe apparatus shall c
8、onsist 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 a vertical position on the same axis asa shaft to which shall be fas
9、tened 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 may be raised by a manually rotated cam. Provisionshall be made by th
10、e 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. (0.5mm) with a typical range of 1.72.5 in. (Note 1). The portionof the scale to be used
11、 shall be adjusted so that when thevertical shaft is measuring a 3.00 in. standard, 3.00 in. is readon the scale.NOTE 1The apparatus as described in this section is capable ofmeasuring workabilities up to about 32 %. For products of higherworkability a suitable spacer block may be installed under th
12、e 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 base orcolumn using steel bolts. Variable results are obtained from thete
13、st unless the described mounting or an acceptable alternativemounting is used for the rammer. An acceptable mountingmethod is one that can be calibrated using the manufacturerscalibration rings described below in 4.1.2.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories
14、and is the direct responsibility of Subcommittee C08.09 on Monolith-ics.Current edition approved Sept. 1, 2009. Published October 2009. Originallyapproved in 1943. Last previous edition approved in 2003 as C 181 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 Maintenance and Calibrati
16、onAs needed, dependingon use, clean all moving parts and lubricate with SAE 10 oil.Make periodic checks of the height that the weight drops toinsure the weight is being raised 2 in. (51 mm). Inspect therammer to determine whether it and the foundation areproducing full ramming energy. This is accomp
17、lished by usingcalibrated impact rings.3Inspect the specimen tube (Note 2).NOTE 2Variation in the smoothness 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
18、 manufacturer.5. Test Specimens5.1 Temperature of Plastic Refractory Since the work-ability index may vary with a wide spread of temperature, thetemperature of the material to be tested must be between 65and 75F (18 and 24C) to reduce this variable. Record thetemperature of material before forming t
19、he cylinder.NOTE 3As much as a 3-point change in the workability index mayoccur within the 10F (6C) stated range.5.2 Number of SpecimensFive cylindrical test specimensshall be molded from the sample of plastic refractory.5.3 Molding of SpecimensThe interior of the mold shallbe cleaned and coated wit
20、h a light film of suitable parting agentprior to the preparation of each specimen. To facilitate fillingthe mold, the sample shall be broken into pieces varying in3Manufacturers calibration rings consist of a set of precision steel rings thatdeform within a specified range to determine full ramming
21、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 of the ring being horizontal.The ring is then subjected to 3 impacts of the rammer head. A measurement acrossthe center of the deformed ring
22、 is then made and compared to the limits specified onthe box containing the rings. Detailed instructions are included in the calibration kit.FIG. 1 Apparatus for Workability-Index TestFIG. 2 Example of Provision to Suspend WeightC181092size, the largest dimension being about 1 in. (25 mm). Thesample
23、 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 % aluminaplastic, approximately 375 g. After placing the material in themold, it shall be subjected to ten impacts by turning the handle,
24、which causes the weight to be raised 2 in. (51 mm) and thendropped upon the collar attached 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 suita
25、bleauxiliary plunger.6. Procedure6.1 Remove the load on the plunger of the mold bysuspending 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 in
26、to the slot in theframework. Raise the vertical shaft using raising device (Fig.1), place the test specimen on the bottom of the mold and lowerthe shaft until the plunger is in firm contact with the specimen.Obtain the length of the specimen to the nearest 0.02 in. (0.5mm) by sighting on the rule an
27、d the end of the shaft. Disengagethe weight from its support and carefully lower it until it is atrest in its normal position. Then apply three impacts from theweight to the test specimen. Read the final length of thespecimen from the scale, and record the difference in inches ormillimeters between
28、the two measurements.7. Calculation and Report7.1 Calculate the percentage deformation 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
29、off to one decimal place.W 5L 2 L1L3 100whereL = length of specimen prior to deformation,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. Prec
30、ision and Bias8.1 Interlaboratory Test Data4An interlaboratory test wasrun in 1975, 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
31、each laboratoryat the same time. The components of variance for workabilityindex results calculated by the procedures given in PracticeD 2906 are as follows:Within-laboratory component 4.1 % of the averageBetween-laboratory component 5.1 % of the average8.2 PrecisionFor the components of variance gi
32、ven in 8.1,two averages of test values should be considered significantlydifferent 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 AverageWith
33、in-LaboratoryPrecisionBetween-LaboratoryPrecision3 6.6 15.65 5.1 15.010 3.6 14.615 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; workabi
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37、mittee 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 serviceastm.org (e-mail); or through the ASTM website(www.astm.org).4Supporting data are available from ASTM International Headquarters. RequestRR: C 08 1003.C181093
