Introduction
Concrete:
· It is a Composite Material
· Rocklike Material
Properties:
· Versatile: Capable of doing many things competently
· Pliable: Can be easily moulded
· Strong High Compressive Strength
· Durable Long Life
· Does not Rust or Rot
· Does Not Need a Coating
· Resists Fire and Water
· Cost Effective
· Sound Insulation
· Aesthetic Appeal
Ingredients:
· Cement: OPC, PPC
· Fine Aggregate: River Sand, Robo Sand (Crusher Dust)
· Coarse Aggregate: Hard Granite Metal of size 10mm, 12mm, 20mm, 25mm, 40mm etc.,
· Water
· Admixtures (optional) Chemical / Mineral Admixtures used to change the properties of fresh concrete during construction
a. Plasticizer To increase workability
b. Retarder To reduce initial setting time
c. Accelerators To increase initial setting time
Drawbacks of Concrete:
· Low Tensile Strength. (Approximately 1/10 of Compressive Strength)
· Cracks develop in concrete due to shrinkage and the application of live loads. It needs mixing, casting, and curing, all of which affect the final strength of concrete
Reinforced Cement Concrete (RCC)
· Steel is used as Reinforcement to have high tensile strength
Principle of Steel Location:
“Place reinforcing steel where the concrete is in tension”
Why Steel is most suitable in RCC?
· More Tensile Strength
· Similar Coefficient of thermal expansion
· Chemical Compatibility
· Adhesion of Concrete To Steel
Types of Steel
· Fe250 - Mild Steel having characteristic tensile strength of 250 N/mm2
· Fe415 - High Yield Strength Deformed Bars (HYSD)
· Fe500 - High Yield Strength Deformed Bars (HYSD)
Steel Rods vs Bars:
· ROD is used for axial loading and torsion
· BARS can be used for axial, torsion as well as bending loads.
Size of Bars: 6mm, 8mm, 12mm, 16mm, 20mm, 25mm, 32mm, 40mm dia.
Uses: RCC is widely used in building construction for the following structures
· Column Footing
· Columns
· Plinth Beam
· Lintels & Sunshade
· Roof Beams
· Roof Slab
· Staircase & Lifts
· Retaining Walls
· Shear Walls
