ψr = 0.8 only when ties/stirrups satisfy spacing near the bend and along ℓdh per §25.4.3.2.
For No. 36 and smaller bars per Table 25.4.3.2
Auto from bar size
Results
Bar diameter, db
15.9 mm
No. 16
Min inside bend
95.4 mm
= 6 db
Straight extension rule
12 db
Per selected hook type
ℓdh (governing)
247.2 mm
max( eqn, 8db, 150 mm )
Eqn contribution
Checks
8 db = 127.2 mm
150 mm absolute minimum
Notes: Geometry is from §25.3 tables. For seismic hoops/crossties use ≥135° hooks and ensure the extension projects into the core. For discontinuous ends with small cover (<65 mm both directions), provide close ties along ℓdh and take ψr = 1.0 as required.