Difficulty: Easy
Correct Answer: All the above
Explanation:
Introduction / Context:
Closely spaced transverse reinforcement in columns confines the core concrete, prevents buckling of longitudinal bars, and anchors lapped splices. Codes specify maximum spacing based on geometric and bar-diameter limits.
Given Data / Assumptions:
Concept / Approach:
The maximum permitted spacing s of ties is the least of several values to ensure proper confinement across different column sizes and bar diameters. Typical limits are tied to: (1) the least lateral dimension of the column, (2) a multiple of the smallest longitudinal bar diameter, and (3) a multiple of the tie diameter.
Step-by-Step Solution:
Check s ≤ least lateral dimension.Check s ≤ 16 × diameter of the smallest longitudinal bar.Check s ≤ 48 × diameter of the transverse reinforcement (tie).Adopt the smallest value among these as the governing spacing.
Verification / Alternative check:
These limits are widely consistent across major RC codes to control buckling and ensure effective confinement and shear capacity.
Why Other Options Are Wrong:
Each individual criterion alone is incomplete; the correct detailing rule uses all of them with the most restrictive controlling the design. Hence “All the above” is appropriate.
Common Pitfalls:
Using only one limit; ignoring changes at laps/hinge regions where closer spacing is required; confusing longitudinal and transverse bar diameters in calculations.
Final Answer:
All the above
Discussion & Comments