RCC and Steel Structures (Civil)

RCC (Reinforced Cement Concrete):

Combines compression strength of concrete with tensile strength of steel.

Design philosophies:

• Working Stress Method (WSM): older.
• Limit State Method (LSM): current (IS 456:2000).

Limit States:

• Ultimate limit state: collapse, strength.
• Serviceability limit state: deflection, cracking.

Common RCC members:

Beams:

• Singly reinforced (tension only).
• Doubly reinforced (compression + tension).
• Flanged: T-beam, L-beam.

Columns:

• Short / long (slenderness).
• Axially loaded / with bending.

Slabs:

• One-way (l/b > 2): flexural in one direction.
• Two-way (l/b ≤ 2): flexural in both.

Footings:

• Isolated, combined, strap, mat.

Standard reinforcement:

• Min steel for beam: 0.85bd/fy.
• Cover: 25-50 mm depending on exposure.

Steel Structures:

• Hot-rolled sections: I, channel, angle.
• Plastic moment capacity: for design.
• Connections: bolted (HSFG), welded.
• Buckling considerations.

Loads (IS 875):

• Dead load: self-weight.
• Live load: people, furniture (3-5 kN/m² residential).
• Wind load: terrain category, height.
• Earthquake load: zone, soil, importance.
• Snow load: for hilly regions.

RRB JE focus: RCC vs steel, common beam types, code IS 456, basic loads.