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Crack Width & Serviceability

Estimate crack width in reinforced concrete beams using the Gergely & Lutz expression (ACI 224R). Compare against exposure-class allowable limits.

Inputs

optional — sets fs
Method — Gergely & Lutz (ACI 224)
  • w = 0.011·β·fs·∛(dc·A) ·10⁻³  (mm), with β = (h-c)/(d-c) ≈ 1.20 typical.
  • A = 2·dc·b / nbars (effective area of concrete around one bar).
  • Compare with allowable per exposure (ACI 224R typical limits).

Results

Effective Tension Area A
β factor
Crack Width w
Allowable wmax
Status