Constructive measures

Constructive measuresLongitudinal reinforcementSections requirementsMinimum sectionMaximum sectionAnchoring lengthOverlap lengthOffset length of bending moment curvesSteel bars installationTransverse reinforcementMinimum sectionShape of transverse steel

 

Longitudinal reinforcement

Sections requirements

Minimum section

In accordance with Eurocode 2 and its French Annex, the section of the longitudinal reinforcements must be such that :

Maximum section

The section of longitudinal reinforcement must not exceed, outside overlapping areas, the maximum value allowed by Eurocode 2 is:

 

Anchoring length

where is the stress in the bar, computed at the section from which the anchor is measured:

where is considered for Fundamental ULS.

CoefficientDescription
Influence factor, depends on the shape of the bars (straight anchorage)
Influence factor, depends on the coating (straight anchorage)
with
where is the coating of the longitudinal bar
and is the distance between the longitudinal bars
Influence factor, depends on confinement by the transversal reinforcements not welded to longitudinal reinforcements
Influence factor, depends on confinement by welded transversal reinforcement
Influence factor, depends on transversal compression confinement

Condition t be fulfilled:

Minimum anchorage length

Pessimist assumption: compressed bar

Finally, the value of the anchor length to be retained for a bar is:

Overlap length

This calculation uses the coefficients previously calculated for the anchor length. We add:

Overlap length:

Minimum overlap length:

 

Offset length of bending moment curves

  1. Calculation of the lever arm:

    h: wall thickness

    : centre of gravity of tensioned reinforcement

  2. Calculation of the offset length that has to be considered:

    : Inclination of concrete rods ()

 

Steel bars installation

Some rules to follow:

Transverse reinforcement

Minimum section

The percentage of transversal reinforcement is calculated as follows :

Even when no shear reinforcement is necessary, a minimum transverse reinforcement is required.

Shape of transverse steel

Several types of transverse steels exist:

Additional length required to guarantee the loading lengths (depending on the diameter of the bar) :