Reinforcing Steel Specs Flashcards
When are lap splices not permitted?
For bars larger than #11, except as provided in 25.5.5.3
What is a Mechanical splice?
A mechanical device joining two bars together.
Conditions for Welded splices
Must be weldable.
Must comply with AWS D1.4
Whether a mechanical or welded splice, the connection should develop at least ____ fy of the bar.
1.25 fy
(“Fy” is yield strength)
(25.5.7.1)
What are the rules for column bar offset?
- Slope of inclined portion must not be greater than 1:6
- Ties must be present in offset area (added in after splicing)
- Offset bars must be bent prior to being set in place.
Sec. 10.7.4.1
What are the three options for splicing rebar?
Lap splice
Mechanical splice
Welded splice
(Splicing cannot be implemented unless specified by the engineer)
Can several splices be allowed to be in the same plane of reinforcing steel?
No, they must be staggered.
Standard hook bends:
90 degrees or 180 degrees
(Table 25.3.1)
Stirrup:
Refers to U, L, or rectangular shaped bars that are wrapped around longitudinal bars and used to resist shear forces and flexural members like beams. They usually terminate with 135 or 90° bend.
Ties:
Referred to a loop of reinforcing bars, that enclose longitudinal vertical bars. They’re typically used to resist sheer and lateral forces and compression members like columns. They also terminate with a 135 or 90° bend.
Hoop:
A term used to describe a tie that terminates with hooks at both ends.
Bundled reinforcement shall be limited to ____ in any one bundle.
4
(25.6.1.1)
Bars larger than a No.____ shall not be bundled in beams.
11
(25.6.1.3)
Bundled bars must be enclosed in ____ or ______.
Ties or stirrups
(25.6.1.2)
If a group of bundled bars is used in a flexural member, then the individual bars ______ all terminate at the same location.
Cannot
(25.6.1.4)
Minimum spacing of parallel nonprestressed reinforcement in a horizontal layer, clear spacing shall be at least the greatest of ___, ___, and ____.
1”, db, (4/3)diameter of aggregate
For parallel nonprestrssed reinforcement placed in two or more horizontal layers, reinforcement in the upper layers shall be placed directly above reinforcement in the bottom layer with a clear space in between layers of at least ____.
1”
(25.2.2)
For longitudinal, reinforcement in columns, pedestals, struts and boundary elements in walls clear space in between bars, shall be at least the greatest of ___, ____, and ____.
1.5”, 1.5db, and (4/3)diameter of aggregate
(25.2.3)
Plain reinforcement (plain bars or wire) are permitted in structural concrete for _______.
Use in spirals.
(20.2.1.1)
The minimum compressive strength (f’c) of concrete is ____.
2500 f’c, psi
(Table 19.2.1.1)
Placement tolerance for location of reinforcement (d) depth and concrete cover:
If less than or equal to 8 inches depth, then +or- 3/8
If greater than 8” depth, then +or- 1/2
Minimum spacing of ties/ hoops:
Min. clear spacing: (4/3)d(agg)
Min. center-to-center spacing: not more than:
• 16db of longitudinal bar
• 48 db of tie bar
• Smallest member dimension
Min. bar diameter:
• #3 for #10 and smaller
• #4 for #11 and larger or bundled bars
Standard hooks are either:
- 180° bend plus 4db extension, but not less than 2-1/2” at free end of bar
- 90° bend plus 12 db extension at free end of bar
Concrete cover:
Member size 12” or less: -3/8” *
Over 12”: -1/2 *
*But not to exceed 1/3 cover
Coarse concrete cannot exceed:
• 1/5 the narrowest dimension between sides of forms
• 1/3 the slab depth
• 3/4 the min. specified cleared spacing between the reinforcement
