Concrete Workability

Confined Flow Test Methods

Only three confined flow tests methods for concrete are presented in this document. However, the use of confined flow in measuring workability is much more extensive than this short list suggests. Many of the tests available for self-compacting concrete are confined flow tests.
Generally confined flow tests are not suitable for low to moderate slump concretes, which are not sufficiently fluid to readily flow under confined conditions and produce meaningful test results.
Since vibration imparts energy into concrete and produces flow in low to moderate slump concretes, some vibration tests feature confined flow. Such tests that incorporate both vibration and confined flow—including the inverted slump cone test and the vertical pipe apparatus—are classified as vibration tests.
The three confined flow tests presented in this document are simple to perform and provide additional information that the slump test does not provide. However, the tests are more complex than the slump test—though much less complex than rotational rheometers—and are not widely used.

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