020301f - Joints And Reinforcement For Concrete Flashcards
What is the purpose of a construction joint?
A joint that ends or stops fresh concrete placement that will be extended at a later time.
A cold joint created at a predetermined location is classified as what type of joint?
Construction joint.
How are construction joints formed in walls or slabs?
Bulkheads
What type of keyway should be used if reinforcement is to be located in the same area as a keyway?
A split keyway
A waterstop such as PVC (polyvinyl chloride) may be installed in what type of joint?
Construction joint
What is the most common method of creating a control joint for a sidewalk or driveway?
Grooving the plastic concrete with a deep cutter or joining tool.
How are control joints formed in vertical walls?
Chamfer strips or Russification strips.
What is the recommended depth do control joints?
At least 20 mm, preferably 25 mm. Rule of thumb: at least as deep as 1/4 thickness of slab material.
What is the minimum recommended width for an expansion joint?
6 mm
When steel reinforcement is used in concrete, it is used to withstand what type of loads?
Tensile
What type of wire must be used to tie epoxy-coated bars?
Non-metallic wire or wire with an acceptable protective coating.
How does welded wire fabric, also referred to as mesh, develop a bond to the concrete?
It’s shape. The positive anchorage at each welded intersection creates the shape.
Why is welded wire fabric used in concrete slabs?
For temperature and shrinkage reinforcement.
What is the minimum concrete cover for reinforcement in footings?
75 mm
20 (columns) to 24 (beams, walls, slabs) times the bar diameter. Though not less than 300 mm. T or F
T
