The amount of water used in a castable mix for preparing test specimens has a significant influence on subsequent test results. This test method is used primarily to determine and reproduce the consistency required for the optimum casting of refractory castables in the preparation of test specimens and to express that consistency quantitatively. The correct water content is one of the major factors that must be controlled to obtain uniform test specimens. Excess water can reduce strength, increase volume shrinkage, and promote segregation of the castable ingredients. Insufficient water can produce “honeycombs” (air voids) in the castable because of poor consolidation during placement and prevent complete hydration of cement.
The flow table (see sketches in Specification C 230/C 230M
Total time of wet mixing must be closely controlled to obtain reproducible results.
This test method is not intended to be used to determine the proper water content for gunning applications, although it may provide information of value for interpretation by a skilled operator.
Область применения1.1 This test method covers the procedure for determining the consistency of castable refractory mixes by the flow table method.
1.2 This test method applies to regular weight castable refractories, insulating castable refractories, and castable refractories that require heavy vibration for forming, which are described in Classification C 401. They also apply to such castables containing metal fibers.
1.3 The values stated in inch-pound-units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard
1.4 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 determine the applicability of regulatory limitations prior to use.