Design Summary
Slab Information

Type: One-Way Slab

Dimensions: 5.0 m × 3.0 m × 0.15 m

Aspect Ratio (L/B): 1.67

Material Properties

Concrete Grade: C25/30 (25 MPa)

Steel Grade: 415 MPa

Concrete Cover: 25 mm

Loading Conditions

Live Load: 3.0 kN/m²

Dead Load: 1.5 kN/m²

Total Load: 6.375 kN/m²

Support Conditions

Support Type: Simply Supported

Effective Depth (d): 120 mm

Span/Depth Ratio: 25.0

Moment Calculations

Short Span Moment (Mx): 12.30 kN·m/m

Long Span Moment (My): 4.43 kN·m/m

Moment Capacity: 15.78 kN·m/m

Shear Calculations

Shear Force (V): 15.94 kN/m

Shear Capacity: 45.21 kN/m

Shear Check: OK

Reinforcement Details

Main Reinforcement: 10 mm @ 150 mm c/c

Distribution Reinforcement: 8 mm @ 200 mm c/c

Area of Steel (Ast): 523.6 mm²/m

Deflection Check

Deflection: 12.5 mm

Permissible Deflection: 20.0 mm

Deflection Check: OK

Visualizations

The diagram shows how the loads are distributed across the slab based on the slab type and support conditions.

The bending moment diagram shows the variation of moments along the span of the slab.

The reinforcement layout shows the placement of main and distribution bars in the slab.

Interactive Guide
1
Select Slab Type

Choose between One-Way or Two-Way slab based on the aspect ratio (L/B). One-Way slabs carry load in one direction when L/B > 2, while Two-Way slabs carry load in both directions when L/B ≤ 2.

2
Enter Slab Dimensions

Input the length, width, and thickness of your slab. The calculator will automatically determine the effective depth based on the concrete cover and reinforcement diameter.

3
Specify Material Properties

Select the concrete and steel grades from the dropdown menus. Higher grades provide greater strength but may be more expensive.

4
Define Loading Conditions

Enter the live load (e.g., floor load) and additional dead load (e.g., finishes). The calculator will combine these with the slab self-weight.

5
Set Support Conditions

Choose the appropriate support condition (simply supported, fixed, or continuous) which affects the moment coefficients used in calculations.

6
Reinforcement Options

Select the diameters for main and distribution reinforcement bars. The calculator will determine the required spacing based on the calculated steel area.

7
Calculate and Review

Click the Calculate button to perform all design checks. Review the results including moments, shear, reinforcement, and deflection checks.

About the Calculator
Slab Design Calculator

This tool helps in designing reinforced concrete slabs based on key structural parameters. It uses standard design codes to calculate bending moments, shear forces, and reinforcement requirements.

Design Methodology

The calculator follows these steps:

  1. Determines slab type based on aspect ratio (L/B)
  2. Calculates total load including self-weight and imposed loads
  3. Computes bending moments using appropriate coefficients
  4. Checks shear capacity at critical sections
  5. Calculates required reinforcement area
  6. Determines bar spacing based on selected diameters
  7. Performs deflection check based on span/depth ratio
Assumptions
  • Concrete density: 25 kN/m³
  • Modulus of elasticity for concrete: 5000√f'c MPa
  • Modular ratio (m): 10
  • Neutral axis depth factor (k): 0.4
  • Lever arm factor (j): 0.9

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This tool is provided for educational purposes only. Professional verification is recommended for actual projects.