Pavement Designer

Design a flexible pavement (AASHTO 1993 structural number SN), a rigid pavement (AASHTO 1993 slab thickness D), or run a PCA fatigue + erosion damage check. US-customary units (psi, in, pci).

⭐ Free to design · Balance … EP

① Method

Flexible pavement — design inputs

Design ESAL, W₁₈ (18-kip)

Reliability R (%)

Overall std. dev. S₀

Subgrade Mᵣ (psi)

Initial serviceability p₀

Terminal serviceability p_t

▸ Optional: check a layered design (SN = a₁D₁ + a₂m₂D₂ + a₃m₃D₃)

a₁ (surface)

D₁ (in)

a₂ (base)

m₂ (drainage)

D₂ (in)

a₃ (subbase)

m₃ (drainage)

D₃ (in)

Leave layers blank to just get the required SN. Layer coefficients aᵢ depend on material (HMA ≈ 0.40–0.44, granular base ≈ 0.13–0.14, subbase ≈ 0.10–0.12) — use your project values.

Rigid pavement — design inputs

Design ESAL, W₁₈ (18-kip)

Reliability R (%)

Overall std. dev. S₀

Terminal serviceability p_t

Initial serviceability p₀

Modulus of rupture S'c (psi)

Concrete E_c (psi)

Subgrade/base k (pci)

Load transfer J

Drainage coeff. C_d

Typical J: 3.2 (with dowels/tied shoulders) to 3.8–4.4 (no load transfer). C_d ≈ 1.0 for fair drainage.

PCA fatigue + erosion — inputs

⚠️ PCA design uses tables. The equivalent stress (psi) and the allowable erosion repetitions are read from the PCA design tables/charts for your trial slab thickness, k-value, and axle type/load. This tool does not ship those tables — look them up and enter them below. It then runs the PCA fatigue (closed-form) and erosion (Miner's-sum) damage analysis on your values.

Modulus of rupture S'c (psi)

Trial slab thickness D (in)

Axle-load groups

For each group enter the expected repetitions nᵢ, the PCA equivalent stress (psi), and — for erosion — the allowable repetitions from the PCA erosion chart. Leave a row blank to skip it.

Group	Expected reps nᵢ	Equiv. stress (psi)	Allow. erosion reps

🛣️ Result

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