Reinforcing Steel Specs

Question 1

When are lap splices not permitted?

Answer 1

For bars larger than #11, except as provided in 25.5.5.3

Question 2

What is a Mechanical splice?

Answer 2

A mechanical device joining two bars together.

Question 3

Conditions for Welded splices

Answer 3

Must be weldable.
Must comply with AWS D1.4

Question 4

Whether a mechanical or welded splice, the connection should develop at least ____ fy of the bar.

Answer 4

1.25 fy

(“Fy” is yield strength)

(25.5.7.1)

Question 5

What are the rules for column bar offset?

Answer 5

1. Slope of inclined portion must not be greater than 1:6
2. Ties must be present in offset area (added in after splicing)
3. Offset bars must be bent prior to being set in place.
   Sec. 10.7.4.1

Question 6

What are the three options for splicing rebar?

Answer 6

Lap splice
Mechanical splice
Welded splice
(Splicing cannot be implemented unless specified by the engineer)

Question 7

Can several splices be allowed to be in the same plane of reinforcing steel?

Answer 7

No, they must be staggered.

Question 8

Standard hook bends:

Answer 8

90 degrees or 180 degrees

(Table 25.3.1)

Question 9

Stirrup:

Answer 9

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.

Question 10

Ties:

Answer 10

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.

Question 11

Hoop:

Answer 11

A term used to describe a tie that terminates with hooks at both ends.

Question 12

Bundled reinforcement shall be limited to ____ in any one bundle.

Answer 12

4

(25.6.1.1)

Question 13

Bars larger than a No.____ shall not be bundled in beams.

Answer 13

11

(25.6.1.3)

Question 14

Bundled bars must be enclosed in ____ or ______.

Answer 14

Ties or stirrups

(25.6.1.2)

Question 15

If a group of bundled bars is used in a flexural member, then the individual bars ______ all terminate at the same location.

Answer 15

Cannot

(25.6.1.4)

Question 16

Minimum spacing of parallel nonprestressed reinforcement in a horizontal layer, clear spacing shall be at least the greatest of ___, ___, and ____.

Answer 16

1”, db, (4/3)diameter of aggregate

Question 17

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 ____.

Answer 17

1”

(25.2.2)

Question 18

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 ____.

Answer 18

1.5”, 1.5db, and (4/3)diameter of aggregate

(25.2.3)

Question 19

Plain reinforcement (plain bars or wire) are permitted in structural concrete for _______.

Answer 19

Use in spirals.

(20.2.1.1)

Question 20

The minimum compressive strength (f’c) of concrete is ____.

Answer 20

2500 f’c, psi

(Table 19.2.1.1)

Question 21

Placement tolerance for location of reinforcement (d) depth and concrete cover:

Answer 21

If less than or equal to 8 inches depth, then +or- 3/8

If greater than 8” depth, then +or- 1/2

Question 22

Minimum spacing of ties/ hoops:

Answer 22

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

Question 23

Standard hooks are either:

Answer 23

1. 180° bend plus 4db extension, but not less than 2-1/2” at free end of bar
2. 90° bend plus 12 db extension at free end of bar

Question 24

Concrete cover:

Answer 24

Member size 12” or less: -3/8” *

Over 12”: -1/2 *

*But not to exceed 1/3 cover

Question 25

Coarse concrete cannot exceed:

Answer 25

• 1/5 the narrowest dimension between sides of forms
• 1/3 the slab depth
• 3/4 the min. specified cleared spacing between the reinforcement