Structural Concrete - Hassoun

8.4 ACI Design Procedure to Build a Strut-and-Tie Model 293
C
C
T
C C C
C – C – C Node
C – C – T Node
T
T
T
C
T
T – T – T Node
C – T – T Node
T
Figure 8.3
Classification of nodes.
C
40 K
D
E
28.3 K
28.3 K
h
A
20 K
h
h
20 K 20 K
B
Figure 8.4
Example of steel truss.
greater than the force in the tie. In this case, adequate concrete areas are available to act as idealized
struts. Steel reinforcement is needed to act as a tie for AB. Proper anchoring of the ties are essential
for a safe design and should be anchored in a nodal zone.
8.4 ACI DESIGN PROCEDURE TO BUILD A STRUT-AND-TIE MODEL
8.4.1 Model Requirements
• Equilibrium of forces should be maintained. Forces in strut and ties should be uniaxial.
• Struts must not cross or overlap each other. They can cross or overlap only at nodes.