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Airfield Rigid Pavement Single-Wheel Edge Stress Screening Calculator

Calculate the Westergaard edge stress in a concrete airfield pavement slab under a single wheel load, as a preliminary screening check.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-26 · v1.0.0

Market
Imperial · sales tax

Single-wheel edge stress

2.24 MPa

Low confidence

This is a SINGLE-WHEEL screening calculation only, using classical Westergaard edge-stress theory. It does NOT account for dual/dual-tandem gear superposition, load repetitions (coverage), or cumulative fatigue damage — real FAA airfield rigid pavement design REQUIRES the FAARFIELD software per AC 150/5320-6. Use this only as a rough preliminary screening indicator, never for final design.

Radius of relative stiffness (l)
41 in
Equivalent radius of resisting section (b)
5.15 in

Running these inputs gives 2.24 MPa as the single-wheel edge stress. Low confidence on these inputs, so use the number to plan rather than to order. Currently reading for United States under IRC 2024 — pick a different market above and the figures re-cast accordingly.

Add the equipment this sizes

This result is a specification — 2.241 MPa — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Full FAA airfield rigid pavement design for dual/dual-tandem gear configurations requires FAARFIELD (layered-elastic/3D-FEM with cumulative fatigue damage analysis per AC 150/5320-6E/F/G) and cannot be reduced to a closed-form formula — multi-wheel superposition and coverage/fatigue life have no simple equation. This calculator instead computes the classical Westergaard edge-loading stress for a SINGLE wheel: σe = 0.572×(P/h²)×[4×log10(l/b)+0.359], where l = [E×h³/(12×(1−μ²)×k)]^0.25 is the radius of relative stiffness and b is the equivalent radius of the resisting section (b=√(1.6a²+h²)−0.675h for a<1.724h, else b=a, where a is the tire contact radius)

Your workspace

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Frequently asked questions

Can this calculator be used for actual FAA airfield rigid pavement design?
No. Full FAA airfield rigid pavement design for dual or dual-tandem gear configurations requires FAARFIELD (layered-elastic/3D-FEM analysis with cumulative fatigue damage per AC 150/5320-6E/F/G) — multi-wheel superposition and coverage/fatigue life have no closed-form equation. This calculator computes only the classical Westergaard edge stress for a single wheel, as a rough preliminary screening indicator.
What do the radius of relative stiffness (l) and equivalent radius of resisting section (b) represent?
The radius of relative stiffness (l) reflects how the slab's own stiffness, thickness, and the subgrade support work together to spread a load. The equivalent radius of resisting section (b) adjusts the tire's actual contact radius for the slab thickness when the contact radius is small relative to the slab (a < 1.724h), per Westergaard's edge-loading formula.
Why is the confidence rating always low?
The confidence is fixed at low because this is explicitly a single-wheel screening formula only — it cannot capture real dual/dual-tandem gear load superposition or fatigue life from repeated aircraft passes, both of which materially affect actual airfield pavement performance and require FAARFIELD analysis.