ASTM C1445-99

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Designation:C1445–99
Standard Test Method for
Measuring Consistency of Castable Refractory Using a Flow
Table
This standard is issued under the fixed designation C1445; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope optimum casting of refractory castables in the preparation of
test specimens and to express that consistency quantitatively.
1.1 This test method covers the procedure for determining
The correct water content is one of the major factors that must
the consistency of castable refractory mixes by the flow table
be controlled to obtain uniform test specimens. Excess water
method.
can reduce strength, increase volume shrinkage, and promote
1.2 This test method applies to regular weight castable
segregation of the castable ingredients. Insufficient water can
refractories, insulating castable refractories, and castable re-
produce “honeycombs” (air voids) in the castable because of
fractories that require heavy vibration for forming, which are
poor consolidation during placement and prevent complete
described in Classification C401. They also apply to such
hydration of cement.
castables containing metal fibers.
3.2 The flow table (see sketches in Specification C230) has
1.3 The values stated in inch-pound units are to be regarded
been found to be an excellent tool for measuring the consis-
as the standard. The values given in parentheses are provided
tency of a castable and should be used in cases where a
for information only.
numericalresultisrequired.Sincecastablesdiffersomewhatin
1.4 This standard does not purport to address all of the
their “body” or plasticity, it has been found that a good casting
safety concerns, if any, associated with its use. It is the
range, expressed numerically, might vary from castable to
responsibility of the user of this standard to establish appro-
castable. While one material may cast well between 40 and
priate safety and health practices and determine the applica-
60% flow, another material may need to be in the 60 to 80%
bility of regulatory limitations prior to use.
flow range to properly flow. Because of this, it has been found
2. Referenced Documents
that no arbitrary optimum range can be stated for all castables.
The flow table then becomes a tool for measuring the flow and
2.1 ASTM Standards:
not determining it. It can allow the operator to follow the
C71 Terminology Relating to Refractories
manufacturer’s recommendations or to reproduce the consis-
C230 Specification for Flow Table for Use in Tests of
tency of a particular castable between laboratories.
Hydraulic Cement
3.3 Total time of wet mixing must be closely controlled to
C 401 Classification of Alumina and Alumina-Silicate
obtain reproducible results.
Castable Refractories
3.4 This test method is not intended to be used to determine
C860 Practice for Determining the Consistency of Refrac-
the proper water content for gunning applications, although it
tory Castable Using the Ball-in-Hand Test
mayprovideinformationofvalueforinterpretationbyaskilled
D346 Practice for Collection and Preparation of Coke
operator.
Samples for Laboratory Analysis
4. Apparatus
3. Significance and Use
4.1 Balance, 15-lb (6.8-kg) capacity, with sensitivity of
3.1 The amount of water used in a castable mix for
0.002 lb (1 g).
preparing test specimens has a significant influence on subse-
4.2 Flow Table, Mold, and Calipers, conforming to the
quent test results. This test method is used primarily to
requirements of Specification C230.
determine and reproduce the consistency required for the
4.3 Tamper,Anonabsorbing, nonabrasive, non-brittle mate-
rial such as a rubber compound having a Shore A durometer
This test method is under the jurisdiction of ASTM Committee C-8 on
hardness of 80 6 10 or seasoned oak wood rendered nonab-
Refractories and is the direct responsibility of Subcommittee C08.09 on Monolithic
sorbing by immersion for 15 min. In paraffin at approximately
Refractories.
392°F (200°C), and the tamper shall have a cross section of ⁄2
Current edition approved Oct. 10, 1999. Published January 2000.
by 1 in. (13 by 25 mm) and a convenient length of 5 to 6 in.
Annual Book of ASTM Standards, Vol 15.01.
Annual Book of ASTM Standards, Vol 04.01.
Annual Book of ASTM Standards, Vol 05.05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1445
(127 to 152 mm). The tamping face shall be flat and at right 5.3 Batchsizesfortheflowtabletestnormallyconsistof10
angles to the length of the tamper. lb(4.5kg)foraregularweightor5lb(2.3kg)foraninsulating
4.4 Trowel, having a steel blade 4 to 6 in. (100 to 150 mm) castable. Mixer size may dictate other sizes. (See 4.5).
in length, with straight edges.
6. Procedure
4.5 Castable Mixer—Either a manually or electrically op-
6.1 Preparation of Castable Sample:
erated (see Fig. 1) mechanical mixer may be used to prepare
6.1.1 Weighthecastablesample(see5.3)tothenearest0.02
batches for the consistency determination. Size the mixing
lb(9g).Placethebatchinthemixerdescribedin4.5(seeNote
bowl to contain 50 to 70% volume loading with the dry batch.
1),anddrymixfor1min.Whilethemixerisoperatingatslow
NOTE 1—Castable-water requirement variation becomes more signifi-
speed, add 90% of the estimated water requirement having a
cantasdryvolumeloadingsdropbelow50%ofthecapacityofthemixer
temperature between 68 and 72°F (20 and 22°C), within ⁄2
bowl because the water required to wet the bowl surfaces changes more
min. Operate the mixer at 50 to 60 rpm, then add additional
rapidly with decreasing volume loadings.
water in small amounts from a tared container, and mix until
4.6 Thermometer, dial-type, metal, with a range from 0 to
the batch appears to have the desired flow.
180°F (−18 to 80°C).
6.1.2 The total actual wet mixing time, including water
4.7 Vibrating Table—An electric vibrating table with 3600
additions,shouldbe3min 610sfordensecastables,5min 6
Hz and at least a 1-ft surface.
10 s for insulating castables, and 4 to 6 min for mixes needing
4.8 Sample Splitter, designed to reduce the castable to the
heavy vibration, unless specified differently by the manufac-
desired weight and ensure that the grain size distribution is
turer.
representative of the original batch.
NOTE 3—Mixing times of less than 5 min for insulating castables may
NOTE 2—AJones or riffle-type sample splitter is satisfactory, provided
influencetheresultsbecauselightweightaggregatesusuallysoakupwater
the openings are large enough to accommodate the largest aggregate
during the initial stages of mixing and affect the consistency of the batch.
particle. If a sample splitter is not available, hand reduction
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