ASTM C1446-99
(Test Method)Standard Test Method for Measuring Consistency and Working Time of Self-Flowing Castable Refractories
Standard Test Method for Measuring Consistency and Working Time of Self-Flowing Castable Refractories
SCOPE
1.1 This test method covers the determination of the consistency (degree of self-flow) and working time of self-flowing castable refractories.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.
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Designation:C1446–99
Standard Test Method for
Measuring Consistency and Working Time of Self-Flowing
Castable Refractories
This standard is issued under the fixed designation C 1446; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope intervals until self-flow is determined to be less than 25 %.
Self-flow is the percent increase in the diameter of the sample
1.1 This test method covers the determination of the con-
afterremovingtheSpecificationC 230conemoldandallowing
sistency (degree of self-flow) and working time of self-flowing
the specimen to flow (spread) under it own weight for 60 s.
castable refractories.
Graph paper, or a functionally equivalent method, is used to
1.2 The values stated in inch-lb. units are to be regarded as
interpolatebetweenthelastreadinggreaterthan25 %self-flow
the standard. The values given in parentheses are for informa-
and the first reading less than 25 % self-flow. Interpolation
tion only.
should be done assuming decay is linear between these two
1.3 This standard does not purport to address all of the
readings. The interpolated elapsed time from the first addition
safety concerns, if any, associated with its use. It is the
of liquid to the mixer to 25 % self-flow is the working time. If
responsibility of the user of this standard to establish appro-
working time is not of interest, consistency at 10 min after
priate safety and health practices and determine the applica-
adding liquid to the mixer is the only self-flow to be measured.
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 This test method is used to measure the consistency
2.1 ASTM Standards:
(degree of self-flow) that a castable refractory demonstrates at
C 71 Terminology Relating to Refractories
a given level of tempering liquid at specified time intervals
C 230 Specification for Flow Table for Use in Tests of
after the liquid is added.Aself-flow of 25 % has been selected
Hydraulic Cement
as the minimum at which a mix can be poured into typical
C 860 Practices for Determining the Consistency of Refrac-
molds or forms in normal practice.
tory Castable Using the Ball-in-Hand Test
5.2 Castable refractories which are self-flowing at one level
C 862 Practice for Preparing Refractory Concrete Speci-
2 of tempering liquid will require vibration for placement at
mens by Casting
some lower level of tempering liquid. At the tempering liquid
3. Terminology levels which require vibration or tamping for placement, the
castable refractory should be characterized using test methods
3.1 Definitions of Terms Specific to This Standard:
which are appropriate for castable refractories designed for
3.1.1 consistency of self-flowing castable refractories—the
vibration placement.
degree of mobility (self-flow) of the refractory castable under
5.3 This test method is not appropriate for determining the
its own weight as described in this test method at the specified
pumpability of castable refractories.
times after adding liquid to the mixer.
3.1.2 working time of self-flowing castable refractories—
6. Interferences (Factors Known to Affect Results)
the elapsed time from the first addition of liquid during mixing
6.1 During method development, a ruggedness evaluation
until the mix will only achieve 25 % self-flow using the
wasperformedusinga5 %cement,17 %reactivealumina,and
procedure described in this test method.
78 % tabular alumina castable. Several factors were found to
4. Summary of Test Method cause statistically significant effects on the measured results.
See ASTM Research Report Number (to be added when
4.1 The castable refractory is mixed with a tempering liquid
available).
and the percentage of self-flow is measured at specified time
6.1.1 Amount of Mixing Liquid—The amount of mixing
liquid affects the measured results for typical self-flowing
This test method is under the jurisdiction of ASTM Committee C-8 on
castable refractories unless added by weight to within 6 0.002
Refractories and is the direct responsibility of Subcommittee
lb (6 1 g) of the target weight for a 16.52–lb (7500-g) sample
Current edition approved Oct. 10, 1999. Published January 2000.
2 weight.The target liquid level is a percentage of the dry weight
Annual Book of ASTM Standards, Vol 15.01.
Annual Book of ASTM Standards, Vol 04.01. of the batch.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1446
6.1.2 Temperature—During ruggedness testing the effect of permanent or temporary. Radial lines scribed lightly at 45°
temperature was evaluated.The test mix, tempering liquid, and intervalsarerecommendedtoaidinmeasuringthesampleafter
room temperature were controlled to the same targets. When flow. The surface must be kept clean and free from oxidation.
the temperature was raised by 3.5°F (70.3 to 73.8°F) working A galvanized or stainless steel or other nonoxidizing metal is
time was found to be reduced by an average of 10 min. While recommended. If the flow surface is an oxidizing metal, a
the degree of this effect may be castable-formulation- lightweight oil can be used to prevent oxidation. The surface
dependent, it is accepted that temperature will affect the must be wiped clean prior to use with an absorbent cloth or
working time for all typical self-flowing castables. clean sponge.
6.1.3 Mold Filling Level—During ruggedness testing it was 7.4 Mixed Castable Storage Container—The mixed
found that filling the mold to a level of ⁄32 in. below the top of castable may either be stored in the mixer bowl between flow
the mold reduced the measured flow at 10 min after adding intervals or transferred to a container for storage. Independent
liquid to the mixer by approximately 5.5 % for a mix with an of the storage container used, it must be sealed airtight to
average flow of approximately 115 % at this elapsed time. prevent evaporation and must be constructed of a nonporous
6.1.4 Mold Lifting Technique—During ruggedness testing it material. The container size should minimize the air space
was found that the technique for lifting the mold from the volume above the stored mixed castable. No more than double
sample affected the results. The techniques compared were the volume of the stored castable is recommended.
lifting the mold straight up and twisting the mold approxi- 7.5 Castable Mixer—The castable mixing equipment shall
mately 45° as it was lifted off the sample. Twisting the mold be in accordance with Practice C 862. Care must be exercised
while lifting resulted in an appropriate 4.5 % increase in the to ensure the appropriate size mixing bowl is chosen. A
measured self-flow at 10 min after adding liquid to the mixer. motor-driven mixer is highly recommended as many self-
6.1.5 Extended Flow Time—During ruggedness testing it flowing castable refractories require high-energy mixing to
was found that a probable effect on measured percent self-flow achieve their self-flowing consistency at the specified liquid
existed when the measurement was made at 70 s after lifting levels.
the mold from the sample as compared to the specified 60 s 7.6 Stopwatch/Timer, capable of being read to 1 s.
after lifting the cone off the sample. 7.7 Balance, accurate to 0.002 lb (1 g).
6.2 Factors which were found to be rugged during method 7.8 Light Mold Release Oil or Vegetable Oil Cooking Spray.
development for percentage self-flow at 10 min after adding 7.9 Absorbent Cloth or Clean Sponge.
tempering liquid to the mixer were (1) ambient temperature
8. Procedure
when varied from 70°F to 74°F, (2) tempering liquid when
8.1 All times, amounts, and conditions are to be in accor-
varied by 0.1 %, (3) time allowed to flow when varied from 60
dance with this practice unless others are specified by the
to 70 s, (4) holding time from filling the mold to lifting the
castable manufacturer/mix provider. Any deviations will be
mold when varied from 20 to 60 s, and (5) lubricating the flow
included in the test report, see Section 10.
surface and wiping clean prior to placing the specimen on the
8.2 Ensure all materials and testing equipment that come in
flow surface as compared to no lubrication on a clean metal
contact with the castable are within 2°F (1°C) of the ambient
surface.
temperature. During the test, the ambient temperature should
6.3 Factors which were found to be rugged during method
not be allowed to change more than 2°F. (see 6.1.2).Whenever
development for working time were (1) time allowed to flow
possible, the ambient temperature during the test should be in
when varied from 60 to 70 s, (2) holding time from filling the
the 68 to 75°F (20 to 24°C) range. Record the actual ambient,
mold to lifting the mold when varied from 20 to 60 s, (3)
dry castable, and mixing liquid temperatures.
lubricating the flow surface and wiping clean prior to placing
8.3 Ensure all equipment is clean and dry. Remove any
the specimen on the flow surface as compared to no lubrication
oxidationfromtheflowplate;lightlylubricateandwipedrythe
on a clean metal surface, (4) returning the castable to the
flow plate and flow mold. Lubricate with a light lubricating oil
storage container after each flow measurement when compared
or a vegetable oil cooking spray. No further lubrication of the
to discarding the castable used for each flow measurement, and
flow plate shall be done until the testing is comp
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