RCC beam deflection check IS:456-2025

RCC Beam Deflection Calculator

INPUT DATA
Beam Type	Simply Supported Continuous Cantilever
Effective Span Le (mm)
Effective Depth d (mm)
Beam Width b (mm)
Area of Compression Steel Asc (mm²)
Ast Required (mm²)
Ast Provided (mm²)
Steel Grade	Fe 415 Fe 500
Section Type	Rectangular T Beam
Flange Width bf (mm)
μG factor	2/3 3/2

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How This Calculator Works

This tool checks whether an RCC beam satisfies deflection limits using the empirical span-to-depth method.

1. Input Parameters

The calculator takes beam geometry, reinforcement details, and material properties. Each value is accessed in JavaScript using getElementById().

2. Basic Span-to-Depth Ratio

led0 = beamType

Depends on support condition (16, 18, or 7).

3. Compression Steel Ratio

pc = (100 × Asc) / (b × d)

4. Modification Factors

μT: Based on tension steel

muT = alpha / (1 + √2 + (fy/415)(Ast_prov/Ast_req))

μC:

muC = 1 - 0.7 × pc

μF:

Rectangular → 1 + (1/3)(1 - pc)
T Beam → 1 + (1/3)(bf/b - pc)

μG: User selected factor

5. Final Check

(Le/d)max = led0 / (μT × μC × μF × μG)
(Le/d)actual = Le / d

If actual value is less → PASS
If more → FAIL