The flow table test or slump-flow test is a method to determine consistency of fresh
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
. Flow table test is also used to identify transportable moisture limit of solid bulk cargoes.
It is used primarily for assessing concrete that is too fluid (workable) to be measured using the
slump test, because the concrete will not retain its shape when the cone is removed.
Application
When fresh concrete is delivered to a site by a truck mixer, its consistency needs to be checked before it is poured into
formwork
Formwork is Molding (process), molds into which concrete or similar materials are either precast concrete, precast or cast-in-place concrete, cast-in-place. In the context of concrete construction, the falsework supports the shuttering mold ...
.
If consistency is not at the desired level, concrete will not have the required strength and other qualities once it has set. If concrete is too pasty, cavities may form within it.
Rebar
Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar used as a Tension (physics), tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concr ...
may become corroded, and concrete will crack. Cavities also reduce the concrete strength.
Equipment
* Flow table with a grip and a hinge, square. In the American version of this test, the table is diameter per .
* Abrams cone, open at the top and at the bottom - high, top diameter, base diameter.
* Water bucket and broom to wet the flow table.
* Tamping rod, long.
Conducting the test
* The flow table is wetted.
* The cone is placed in the center of the flow table and filled with fresh concrete in two equal layers. Each layer is tamped 10 times with a tamping rod.
* Wait 30 seconds before lifting the cone.
* The cone is lifted, allowing the concrete to flow.
* The flow table is then lifted up 40mm and then dropped 15 times, causing the concrete to flow.
* After this the diameter of flow of the concrete is measured
See also
*
Concrete slump test
The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows. It can also be used as an indicator of an impr ...
*
Duff Abrams
Duff A. Abrams (1880, Illinois, – 1965, New York) was an American researcher in the field of composition and properties of concrete. He developed the basic methods for testing concrete characteristics still in use today. A professor with the Lewi ...
*
References
External links and sources
*DIN EN 12350-5
* Standard Test Method for Flow of Hydraulic Cement Mortar
b-i-m(German)
(German)
Concrete Flow Table in an online shop
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