Before The Pour
The Styro Stone EPS formwork is held securely in position by means of the trestle support system. The concrete used for above ground structures should be a ready mixed, uniform pump grade M20 and a grade M30-35 for below ground.
The concrete should be obtained from a plant approved by the Quality Control Scheme for Ready Mixed Concrete QSRMC or as per ISO-10262-2009. 10 mm should be the maximum aggregate size and a minimum 350-375 (kg/cu meter) cement content with a slump factor of 75-120mm. depending on the application. Click here for more details.
The pump hose should be fitted with a type 65 exit nozzle. Styro Stones have a density of 30kg/m? which will allow a type 100 exit nozzle to be used. However, the greater the diameter, the higher the pressure load when pouring, making the accurate placement of the concrete into the void more difficult.
When pouring the concrete, the placement hose should be held vertical.
Generally it is not necessary to stir, vibrate, pound or similar, in order to eliminate voids. This is only carried out on walls heavily reinforced with steel, and even then, only by hand tamping.
To confirm that there are no voids simply tap the walls.
You can normally pour up to a height of 3 m.
After The Pour:
Check all walls are vertical, then adjust by pushing, where necessary before the concrete has had time to cure.
By the following morning it will be too late!
If you have used the trestle support system correctly, you will probably not need to make any such adjustments, it is good to check anyway.