Design of RCC One-Way Slab as per IS 456:2000

Summary

This video provides a comprehensive guide to designing a one-way reinforced cement concrete (RCC) slab according to IS-456:2000 standards. It covers key aspects such as determining whether the slab is one-way or two-way, calculating the slab thickness, effective spans, loads, and moments, as well as the required reinforcement area. The design is illustrated through a practical example of a simply supported slab for an office room, detailing the calculation process for both bending moments and shear forces, alongside reinforcement detailing. Viewers will gain a clear understanding of the design procedure and essential engineering principles.

Takeaways

• 📏 The design procedure is based on IS 456:2000 code provisions for one-way RCC slabs.
• 🏢 The slab is designed for an office room with dimensions of 4 m by 10 m, supported by brick walls.
• ⚖️ A live load of 4 kN/m² is assumed for the slab's design calculations.
• 🧱 The concrete grade is M20 (fck = 20 N/mm²) and the steel grade is Fe415 (fy = 415 N/mm²).
• ➡️ The slab is classified as one-way due to a longer span-to-shorter span ratio of 2.5.
• 📐 The initial thickness of the slab is determined to be 185 mm, considering effective depth and cover.
• 🔄 The effective span is calculated using clear span plus effective depth, resulting in 4.16 m.
• ⚖️ Total design load is calculated using dead and live loads, yielding a factored load of 15.19 kN/m.
• 🔄 The ultimate bending moment (Mu) and shear force (Vu) are computed to ensure structural adequacy.
• 🔧 Main reinforcement consists of 10 mm bars at 125 mm spacing, while distribution bars are 8 mm at 200 mm spacing.

Q & A

What is the primary focus of the video?

The video demonstrates the design procedure of a one-way RCC slab as per IS 456:2000, explaining the basic concepts and calculations involved.

What are the dimensions of the office room for which the slab is designed?

The clear dimensions of the office room are 4 meters by 10 meters.

How is it determined whether a slab is one-way or two-way?

A slab is classified as one-way if the ratio of the longer span to the shorter span is greater than 2. In this case, the ratio is 2.5, indicating it is a one-way slab.

What is the assumed span-to-depth ratio for the slab design?

The assumed span-to-depth ratio for the design is 25.

What is the total thickness of the slab calculated in the design?

The total thickness of the slab is calculated to be 185 mm, which includes effective depth and clear cover.

How is the total design load on the slab calculated?

The total design load is calculated using a load combination of dead load and live load, with a partial safety factor of 1.5, resulting in a total of 15.19 kN/m.

What are the key calculations performed to check the adequacy of the slab?

The key calculations include determining the ultimate bending moment, ultimate shear force, and the limiting moment of resistance, confirming that the assumed thickness is safe.

What is the required area of steel reinforcement calculated for the tension side of the slab?

The required area of steel reinforcement for the tension side is calculated to be 618 mm².

What is the minimum required distribution reinforcement according to the IS code?

According to the IS code, the minimum required distribution reinforcement is 222 mm².

How is the shear strength of the slab verified?

The shear strength is verified by calculating the nominal shear stress and comparing it with the design shear strength derived from the percentage area of steel provided and the grade of concrete.