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Stepoc Technical Information

Concrete Mix

The concrete should possess the characteristic strength specified by the structural engineer who has carried out the design of the wall, but not less than 35N/mm2, and in accordance with BS EN 206 Part 1:2000.

Block Type Concrete Infill
200mm 0.12m3 per m2
256mm 0.15m3 per m2
325mm  0.19m3 per m2








The concrete should be designed to be suitable for the specific means ofdelivery, possessing a slump of no less than 150mm. The maximumaggregate size should not exceed 10mm and the mix should contain not less than 300kg of OPC per cubic metre of fresh concrete. Filling is best accomplished by a concrete pump or skip with a 75mm nozzle, and the design of the concrete should take this into account. Mechanical vibration must not be used. The use of water reducing agents is acceptable to lower cement content in the mix design.

Reinforcement Detailing & Design

For standard cantilever retaining walls only the general principle within BS EN 1996-1-1 allows the height of the wall to be based on 18 times the effective depth. The sections below show the position of the vertical steel on the retained face for each width of Stepoc.


Vertical bar spacings for 200, 256 and 325 STEPOC are based on multiples of 200, 133 and 162.5mm respectively. Horizontal bar spacings are based on multiples of 225mm for all three units.

Area of Steel in mm²/m² of wall based on vertical bars at appropriate centres for the block size.

  BAR SIZE (mm)
8 10 12 16 20 25 32
200 (200mm c/c)
 251.33  392.7 565.49 1005.31 1570.8 2454.37 4021.24
256 (133mm c/c)
 377.94  590.52 850.36 1511.74 2362.10 3690.78 6046.97
325 (162.5mm c/c)
 309.33  483.32 695.98 1237.30 1933.29 3020.76 4949.22

 Typical Example wall calculation can be downloaded below:

Typical 200mm Stepoc Wall Calculation      

Typical 256mm Stepoc Wall Calculation         

Typical 325mm Stepoc Wall Calculation         


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