ASTM C860

ASTM C860 – Standard Test Method for Determining the Consistency of Refractory Castable Using the Ball-In-Hand Test

Description:

Significance and Use

3.1 This test method is used to determine if a freshly mixed refractory castable is of the proper consistency to provide optimum performance. There are times when the manufacturer’s specified water content and consistency will purposely not lead to the correct ball in hand but should be used to provide optimum performance. Contact the manufacturer when in doubt. This test method can also be used to estimate the correct water addition rate of a castable when either the manufacturer’s specified water content is not available or when unique circumstances have rendered that recommendation unusable.

3.2 The correct water content is an important factor that must be controlled to obtain optimum castable performance. 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 the insufficient mobility during placement and, in extreme cases, can prevent the complete hydration of the cement (if used).

3.3 The ball-in-hand test is subjective and somewhat depends on the skill of the operator. However, it is a universally accessible method due to the simplicity of the equipment required, and it is readily used in the field.

3.4 The total wet mixing time of a castable influences the rheological and final properties and therefore should be monitored.

3.5 This test method can be performed in a laboratory or on a job site.

Scope

1.1 This test method covers the procedures for determining the consistency of a castable using the ball-in-hand test. The amount of water used in a castable has a significant influence on its performance.

1.2 This test method applies to castable refractories that are described in Classification C401. It also applies to such castables containing metal fibers.

1.3 This test method is not intended to determine the proper consistency for gunning, pumping, or self-flow applications.

1.4 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.