Jump to content

Flow table test

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Stephen Henry Davies (talk | contribs) at 10:40, 18 September 2009 (Grammar). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Equipment; flow table, upside down funnel, waterbucket and broom.
The upside down funnel filled with concrete prior to lifting.
The diameter of the resulting flow is measured.
These images show a flow test with very fluid concrete for a special application which made compression impossible.

The flow table test or flow test is a method to determine the consistence of fresh concrete.

Application

When fresh concrete is delivered to a site by a truck mixer it is sometimes necessary to check its consistence before pouring it into formwork.

If the consistence is not correct, the concrete will not have the desired qualities once it has set, particularly the desired strength. If the concrete is too pasty, it may result in cavities within the concrete which leads to corrosion of the rebar, eventually leading to the formation of cracks which will accelerate the whole process, rather like insufficient concrete cover. Cavities will also lower the stress the concrete is able to support.

During the test the site engineer should be present.

Equipment

  • Flow table with a grip and a hinge, 70 cm x 70 cm.
  • Upside down funnel which is open at the top and at the bottom - 20cm high, 13 cm top diameter, 20cm base diameter.
  • Water bucket and broom for wetting the flow table.

Conducting the test

  • The flowtable is wetted.
  • The upside down funnel is placed on the flowtable and filled with fresh concrete.
  • The funnel is lifted up, allowing the concrete to flow.
  • The flowtable is then lifted up several centimeters and then dropped, causing the concrete flow a little bit further.
  • After this the diameter of the concrete is measured. The result is called "Ausbreitmaß" in German.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Flow_table_test&oldid=314694885"