Struts and ties

Compression struts usually:

  • Serve as the compression element of the truss mechanism which resists the moment;
  • Serve as the diagonal struts which transfer shear to the supports.


Diagonal struts are usually oriented parallel to the expected axis of cracking.

Tension ties usually include stirrups or longitudinal reinforcement.


Factors affecting the size of the compression strut:

  • Location and distribution of reinforcement and its anchorage;
  • Size and location of bearing.


The compression resistance (design strength) of struts σRd,max is calculated according to the rules of NEN-EN1992-1-1#6.5.2.   


Angle θ (Theta):
The angle θ between the axes of any strut and any tie included in one node should not be taken less than ~25°. The minimum value of the θ angle can be limited by the national code and structure type.