User:Knipptang/builditup
The document includes a test method for the determination of the consistence of fresh concrete by measuring the flow, which occures when releasing the plate of the flow table of a defined volume of concrete. The method is based on ISO 9812 "Fresh concrete - Determination of consistency - Flow test".
These images show a flow test with very fluid condrete for a special application which made compression impossible.
The Flow test is a method to determine the consistence of fresh concrete.
Application
[edit]When fresh concrete is delivered to a site by a truck mixer it is somtimes necessary to check its consistence before pouring it into the formwork.
If the consistence is not all right, the concrete won't have the desired quality - in particular not the desired stregth.
During the conduction the site engineer should be around.
If the concrete is too pasty this might result in cavities inside the hard concrete which leads to corrosion of the rebar, which again leads cracks which will accelerate the whole process - just like few concrete cover. Cavities will also lower the stress the concrete part is able to support.
Equipment
[edit]- 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
- water bucket and broom for wetting the flow table
Conduct
[edit]- The flowtable is wettened
- The upside down funnel is filled up with fresh concrete
- The upside down funnel is lifted up and the concrete flows
- The flowtable will be lifted up several centimeters and will be dropped. These commotions will make the condrete flow a little bit further.
- After this the diameter of the concrete is measured with a yardstick. The result is called "Ausbreitmaß" in german.
Links and Sources
[edit]- DIN EN 12350-5
- b-i-m (german)
- Heidelberg Cement (german)