Crack Width Calculator (ACI 318-19M)

Calculate maximum crack width in reinforced concrete structures per ACI 318-19M Chapter 24. Professional tool for service load conditions, exposure classifications, and crack control verification.

Inputs

Material Properties

Concrete f'c (MPa)

Steel fy (MPa)

Steel Es (GPa)

Section Geometry

Bar diameter db (mm)

Clear cover (mm)

Bar spacing s (mm)

Member thickness h (mm)

Loading & Stress

Steel stress fs (MPa)

Service load steel stress

Exposure condition

Member type

Analysis Parameters

β factor

Ratio of distances to neutral axis (1.0-1.5)

θ (degrees)

Angle of principal tensile stress

Check crack width limit

📊 Results

Enter parameters to calculate crack width per ACI 318-19M Chapter 24.

Design Basis (ACI 318-19M Chapter 24)

Crack Width Formula (24.3.2)

w = 2fs/(Es) × β × √(dc² + (s/2)²) × 10⁻³

Where dc = clear cover + db/2

Maximum Allowable Widths

Interior: 0.41 mm | Exterior: 0.30 mm | Earth contact: 0.25 mm

Steel Stress Calculation

fs = service load moment / (As × jd) where j ≈ 0.9

β Factor Guidelines

Normal cases: 1.2 | High moment gradient: 1.0-1.35 | Complex loading: vary as needed

Note: Crack width calculation per ACI 318-19M §24.3. Steel stress should be calculated from service loads. Consider shrinkage and temperature effects for final design.