Strut and Tie Method

Strut and Tie is a unified approach that consider all load effect ( Moment, Axial, shear and torsion) simultaneously. This design method is useful for shear critical structure and for others disturbed region in concrete structures. Hence Strut and Tie model provides a rational approach by representing a complex structural member with an appropriate simplified truss model.

Code of Practice : ACI, EC, SC

The Basic Concept of Strut and Tie Model : A framework where the stress distribution in a structure is idealized as a system of

1. Strut = Compression member (concrete)
2. Tie/stirrup = Tension member (reinforcement)
3. Node = Connection (Concrete)

Example: Strut and Tie model In Beam


Strut
1. Serves as compression chord of the truss mechanism which resists moment.
2. Serves as diagonal struts which transfer shear to the support.
3. Diagonal struts are generally oriented parallel to the expected axis of cracking.

Ties
The most critical consideration is the provision of adequate anchorage for the reinforcement.

Assumption in design :
1. Tension in concrete is neglected
2. Forces in strut and tie is uni-axial
3. External load applied on node

Strut and Tie method is using for transfer shear wall design in Esteem 7.