RCC BEAM DESIGN GUIDE
RCC Beam Design Example
Learn RCC beam design with a practical example as per IS 456. Understand load calculation, bending moment, shear force, effective depth, reinforcement steel, and basic design steps for reinforced concrete beams.
Open Beam Design CalculatorQUICK ANSWER
How to design an RCC beam?
RCC beam design is done by calculating loads, bending moment, shear force, effective depth and required reinforcement. For a simply supported RCC beam carrying uniformly distributed load, maximum bending moment is commonly calculated using Mu = wuL² / 8 and shear force is calculated using Vu = wuL / 2.
| Design Item | Formula / Value | Result |
|---|---|---|
| Beam Span | L | 4 m |
| Factored Load | wu | 25 kN/m |
| Bending Moment | Mu = wuL² / 8 | 50 kNm |
| Shear Force | Vu = wuL / 2 | 50 kN |
| Effective Depth | Overall depth - cover - half bar diameter | 417 mm |
Example: For a simply supported beam of 4 m span with 25 kN/m factored load, bending moment is 25 × 4² / 8 = 50 kNm and shear force is 25 × 4 / 2 = 50 kN. After this, reinforcement is selected based on bending moment, effective depth, concrete grade and steel grade.
What is RCC Beam Design?
RCC beam design is the process of designing a reinforced concrete beam to safely resist bending moment, shear force, dead load, live load and other structural loads. Concrete resists compression and steel reinforcement resists tension.
RCC beam design is commonly used in residential buildings, commercial structures, slabs, frames, lintels and other structural systems.
RCC Beam Design Formula
For a simply supported beam with uniformly distributed load, maximum bending moment is calculated using wuL² / 8.
Beam Design Data
- Beam span = 4 m
- Beam width = 230 mm
- Beam depth = 450 mm
- Concrete grade = M20
- Steel grade = Fe415
- Factored load = 25 kN/m
Step 1: Calculate Bending Moment
Maximum bending moment for a simply supported beam:
Mu = wuL² / 8
Mu = 25 × 4² / 8
Mu = 50 kNm
Step 2: Calculate Shear Force
Vu = 25 × 4 / 2
Vu = 50 kN
Step 3: Calculate Effective Depth
Effective depth is calculated by subtracting clear cover and half bar diameter from overall depth.
Effective Depth = Overall Depth - Cover - Half Bar Diameter
Effective Depth = 450 - 25 - 8
Effective Depth = 417 mm
Step 4: Reinforcement Design
Main reinforcement is designed to resist tensile stresses caused by bending moment. The required steel area depends on bending moment, effective depth, concrete grade and steel grade.
In practical design, bottom reinforcement is provided in the tension zone and stirrups are provided to resist shear force.
Important Checks in Beam Design
- Depth and span check
- Bending moment capacity check
- Shear force check
- Minimum reinforcement check
- Maximum reinforcement limit
- Deflection check
- Development length check
- Spacing and cover requirements
Uses of RCC Beam Design
- Residential building beams
- Commercial building frames
- Lintel beam design
- Roof beam design
- Floor beam design
- Structural design and quantity estimation