Calculation reinforcement cover

  • Module code ESA1603
  • Software
    • SCIA Engineer
  • FAQ topic

The concrete cover is the distance between the surface of the reinforcement closest to the nearest concrete surface (including links and stirrups and surface reinforcement where relevant) and the nearest concrete surface.

The procedure to find the final cover starts with the nominal cover which is defined as a minimum concrete cover c_min plus an allowance in design for deviation delta(c_dev), see 4.4.1.3 (EN 1992-1-1:2004).

 

Calculation of the minimal concrete cover

For this calculation, SCIA Engineer will calculate the minimal concrete cover c_min from different scenarios and then choose the maximum as shown from the formula 4.2:

 

We can illustrate this with following example:

  • Rectangular cross-section 300 * 300 mm
  • Diameter of the longitudinal bars = 16 mm
  • Diameter for shear stirrups = 8 mm

Calculation of the minimal cover due to the bond requirement:

  • c_min,b,l = 16 mm
  • c_min,b,s = 8 mm
  • c_min,b = Max (c_min,b,l-Diameter of stirrups ; c_min,b,s)
  • c_min,b = Max (16-8;8) = 8 mm

Minimal cover due to environmental conditions XC3, XD0, XS0, XF0, XA0

Structural class = S3

Now, from Table 4.4N, we can calculate c_min,dur:

So, c_min,dur = 20 mm

And based on 4.4.1.3, the allowance in design for deviation = 10 mm (recommended value)

In this example, we will ignore the reductions due to additives, usage of stainless steel and additional protection. So, c_min = Max( 8;20+0-0-0-0;10) = 20 mm

So, the final cover will be: c_nom = c_min + delta(c_dev) = 20 + 10 = 30 mm

If desired, you can define this value manually on two locations:

  • Via the Design defaults in the Concrete settings (Main menu > Design > Concrete Settings > settings):

 

  • Via the concrete member data (Input panel > workstation Concrete > category Concrete Additional data > Concrete 1D data or Concrete 2D data):

By default, the calculation of the cover is set to Automatic.