JOINTS

Joints are 'Planned Break' in concrete which allow RCC to move and prevent random cracking.

TYPES OF JOINTS

1.CONSTRUCTION JOINTS

• Provided where the construction work stops temporarily.
• Tie bar are provided for good bonding.
• Should not be provided at corner(high shear force) and middle(high bending moment).
• Provided at 2/3 part of the span.
• 3m<construction joint<18m</li>

2.EXPANSION JOINT/ISOLATION JOINT

• This joint is provided in builidings larger than 45m.
• C/C spacing of joints.
  • Wall,frame structure~30m
  • Open slab ~ 15m
  • Parapet/Coping ~ 6-12m
• Dowel bars,Joint filler,Joint sealer are used to connect slab.

3. CONTRACTION JOINT/CONTROL JOINT

• It is a joint that is put in the concrete to control cracking.
• Maximum joints at 4.5 metre in unreinforced slab.
• In roof,wall and floor 5-10m spacing between shrinkage joints.