declared calculation basis
Move from stress to a buildable link ratio.
The calculation implements the ordinary beam-region route in Hong Kong Concrete Code clause 6.1.2.5. It assumes the longitudinal steel used in As continues and is anchored as required beyond the section.
Applied and concrete shear stress
EQUATION 6.19
v = V/(bvd)TABLE 6.3 EXPRESSION
vc = (0.79/1.25)(100As/bvd)1/3(400/d)1/4(fcu/25)1/3The reinforcement percentage is limited to 0.15–3.0 for the table expression. The concrete-strength multiplier is applied above 25 MPa with fcu capped at 80 MPa. Because this page requires minimum links, the (400/d)1/4 factor is not taken below 1.
Vertical links
TABLE 6.2
Asv/sv ≥ bvvr/(0.87fyv) or bv(v − vc)/(0.87fyv)The minimum-link stress vr is 0.4 MPa up to fcu = 40 MPa and 0.4(fcu/40)2/3 above it. Designed links replace the minimum expression when v exceeds vc + vr. The absolute stress limit is min(0.8√fcu, 7 MPa), and the longitudinal spacing screen is 0.75d.
What this page does not check
- Enhanced resistance close to supports, axial-force corrections, prestressing, bent-up bars, torsion, or shear–torsion interaction.
- Transverse link-leg spacing, anchorage, curtailment, cover, congestion, laps, fire, fatigue, durability, or SLS.
- Deep beams, corbels, pile caps, openings, interfaces, joints, slabs, punching shear, or discontinuity regions.
- Loading, combinations, analysis, or professional submission requirements.