Brief Summary: ACI 318-19 Chapter 10 – Columns
1. Scope (§10.1)
- Covers nonprestressed and prestressed concrete columns and pedestals.
- Composite columns (e.g., steel-filled) are excluded and addressed in AISC 360.
2. General Provisions (§10.2)
- Materials must comply with Ch. 19 (concrete) and Ch. 20 (steel).
- Connections:
• Beam-column joints: Ch. 15
• Precast connections: §16.2
• Foundation connections: §16.3
3. Design Limits (§10.3)
- Small cross-sections allowed with increased workmanship needs (§10.3.1).
- Effective area adjustments permitted if not in seismic systems (§10.3.1.2).
4. Required Strength (§10.4)
- Strength calculated using factored load combos (Ch. 5) and procedures (Ch. 6).
- Must consider Pu and Mu from all load combinations (§10.4.2.1).
5. Design Strength (§10.5)
- Check all effects:
• Axial (ϕPn ≥ Pu), §10.5.1.1(a)
• Flexure (ϕMn ≥ Mu), §10.5.1.1(b)
• Shear (ϕVn ≥ Vu), §10.5.1.1(c)
• Torsion (ϕTn ≥ Tu), §10.5.1.1(d)
- Torsion usually negligible (§R10.5.4).
6. Reinforcement Limits (§10.6)
- Longitudinal: 1% ≤ ρ ≤ 8% of Ag (§10.6.1.1).
- Shear: Av,min required if Vu > 0.5ϕVc (§10.6.2.1).
7. Reinforcement Detailing (§10.7)
- Min. bars: 3 (triangular), 4 (rect/circular), 6 (spirals) (§10.7.3.1).
- Offset bars: max slope 1:6; ≥75mm offset requires dowels (§10.7.4).
- Splicing: Class A/B based on stress level (§10.7.5.2.2).
- Transverse reinforcement: Ties, hoops, or spirals per §§10.7.6.1–10.7.6.5.