This document provides details and requirements for reinforcement in concrete structures. It discusses standard hooks used for reinforcement, minimum diameters for bar bending, surface conditions of reinforcement, placement of reinforcement, tolerances, spacing limits, bundled bars, tendons and ducts, concrete protection, headed shear and stud reinforcement, corrosive environments, column reinforcement including lateral ties and spirals, lateral reinforcement for beams, and requirements for structural integrity.

1. ASSIGNMENT
Summary about Details of Reinforcement:
Submitted By:
Zeeshan Haider ( 2k16-24)
Allah Yar Babar(2k16-25)
M.Yousif Nazar(2k15-32)
Mubasshir Hussain(2k14-11)
Submitted To:
Engr.Khurram Bukhari Shab
Department:
Civil Engineering

2. Standard hook Used for Reinforcement:
Every project has “hooked” reinforcing shown in at least one detail. Many
drawings refer to “standard hooks” and show hooked bars in specific areas for top
and bottom reinforcing.
Minimum Diameters of Bend:
The minimum diameter Øm (mandrel diameter) to which a bar is bent shall be such
to avoid bending cracks to the bar and ensure the integrity of concrete inside
the bent of the bar where large forces appear.

3. Bending In Reinforcement:
Bending of bars is defined as the process of bending reinforcing steel into shapes
required for reinforced concrete construction. Here, the term D is diameter
of reinforcing steel. Bar bending schedule is a list of the steel reinforcement, which
is used in the concrete structure.
Surface Condition of Reinforcement:
AS 3600, Clause 19.2. 4 states: “At the time concrete is placed, the surface
condition of reinforcement shall be such as not to impair its bond to the concrete or
its performance in the member. ... Rain may wash rust off reinforcing steel laid in
formwork such that it stains visible concrete.
At the time concrete is placed, reinforcement shall be free from mud, oil, or other
nonmetallic coatings that decrease bond. Prestressing steel shall be clean and free
of oil, dirt, scale, pitting and excessive rust. A light coating of rust shall be
permitted.
Placing of Reinforcement:
Incorrect reinforcing steel placement can and has led to serious concrete structural
failures. Placing reinforcement atop a layer of fresh concrete and
then pouring more on top is not an acceptable method for positioning. You must
use reinforcing bar supports, which are made of steel wire, precast concrete, or
plastic.
Tolerance of Reinforcement:
Tolerances in construction are generally a variation in a
dimension, construction limit, or physical char- acteristic of a material. They are a
practical variation related to the function of the material or finished work and
commonly accepted standards of the construction industry.
Tolerances for d and for concrete cover in flexural members, walls, and
compression members shall be as follows:

4. Spacing Limits For Reinforcement:
The maximum spacing between two parallel main reinforcing bars in caseof RCC
Slab shall be 3d or 300 mm or whichever is less. the maximum spacing between
two secondaryparallel bars in case of RCC Slab shall be 5d or 450 mm or
whichever is less.
Bundled Bars:
A group of parallel reinforcing bars (not exceeding four in number) in contact with
each other, enclosed in stirrups or ties; used
as reinforcement in reinforced concrete.Groups of parallel reinforcing bars bundled
in contact to act as a unit shall be limited to four in any one bundle.Individual bars
within a bundle terminated within the span of flexural members shall terminate at
different points with at least 40db stagger.
Where spacing limitations or concrete cover requirements are based on bar
diameter, db, a unit of bundled bars shall be treated as a single bar of a diameter
derived from the equivalent total area.
Bars larger than No. 36 shall not be bundled in beams.
Tendons and Ducts:
Center-to-center spacing of Pretensioning tendons at each end of a member shall
be not less than 4db for strands, or 5db for wire, except that if specified
compressive strength of concrete at time of initial process.Bundling of post-
tensioning ducts shall be permitted if shown that concrete can be satisfactorily
placed and if provision is made to prevent the prestressing steel, when tensioned,
from breaking through the duct.

5. Concrete Protection for Reinforcement:
1- Cast-in-place concrete (nonprestressed)
2- Cast-in-place concrete (prestressed)
Headed Shear and Stud Reinforcement:
Shear studs refer to the installation of steel pins or grommets, that extend out of the
top flange of a steel support beam. Normally the shear studs are welded, with a
spot welder, after the metal deck is installed over the supporting structural steel. ...
The stud will have failed due to a shear force.
Stud Rail is a double-headed stud anchor (DSA) reinforcement system, typically
used for concrete deck-to- column connections. The system is designed to transfer
the load further into the concrete deck, create a larger shear area around the
column, and resist punching shear forces.
Corrosive Environment of Reinforcement:
In corrosive environments or other severe exposure conditions, amount of concrete
protection shall be suitably increased, and the pertinent requirements for concrete
based on applicable exposure categories.
Future Extension of Reinforcement:
Exposed reinforcement, inserts, and plates intended for bonding with future
extensions shall be protected from corrosion.
Column Reinforcement Details:
Columns are essentially required with the primary longitudinal reinforcement and
lateral ties to avoid buckling of the primary bars. The details of minimum and
maximum limits of reinforcements, minimum no.
Offset Bars : Offset bent longitudinal bars shall conform to
the following:

6. 1. The maximum slope of inclined portion of an offset bar with axis of
column shall not exceed 1 in 6.
2. Portions of bar above and below an offset shall be parallel to the axis of
column.
Horizontal supportat offset bends shall be provided by lateral ties,
spirals, or parts of the floor construction. Horizontal supportprovided
shall be designed to resist 1.5 times the horizontal componentof the
computed force in the inclined portion of the offset bars. Lateral ties or
spirals, if used, shall be placed not more than 150 mm away from points
of bend.
3. Offset bars shall be bent before placement in the forms (see the table
below). Where the face of the column above is offset 75 mm or more
from the face of the column below, longitudinal bars shall not be
permitted to be offset bent. The longitudinal bars adjacent to the offset
column faces shall be lap spliced using separate dowels.
Column
Reinforcement Detailing | Reinforcement Detail for Column
Steel Cores:Load transfer in structural steel cores of compositecompression
members shall be provided by the following:

7. 1. Ends of structural steel cores shall be accurately finished to bear at end
bearing splices, with positive provision for alignment of one core above
the other in concentric contact.
2. At end bearing splices, bearing shall be considered effective to transfer
not more than 50 per cent of the total compressive stress in the steel core.
3. Base of structural steel section shall be designed to transfer the total load
from the entire compositemember to the footing; or, the base shall be
designed to transfer the load from the steel coreonly, provided ample
concrete section is available for transfer of the portion of the total load
carried by the reinforced concrete section to the footing by compression
in the concrete and by reinforcement.
Lateral Reinforcement for Columns:
Spirals : Spiral reinforcement for columns shall conform to the following:
(a) Spirals shall consistof evenly spaced continuous bar or wire of such size and so
assembled as to permit handling and placing without distortion from designed
dimensions.
(b) Size of spirals shall not be less than 10 mm diameter for cast‐in‐place
construction.
(c) The minimum and maximum clear spacing between spirals shall be 25 mm and
75 mm respectively.
(d) Anchorage of spiral reinforcement shall be provided by 1.5 extra turns of spiral
bar or wire at each end of a spiral unit.
(e) Splices in spiral reinforcement shall be lap splices of 48 spiral diameter for
deformed uncoated bar or wire and 72 spiral diameter for other cases, but not less
than 300 mm.
(f) Spirals shall extend from the top of footing or slab in any storey to the level of
the lowest horizontal reinforcement in members supported above.
(g) Spirals shall extend above termination of spiral to bottom of slab or drop panel,
where beams or brackets do not frame into all sides of a column.
(h) Spirals shall extend to a level at which the diameter or width of capital is 2

8. times that of the column, in case of columns with capitals.
(i) Spirals shall be held firmly in place and true to line.
Tie reinforcement for compression members shall conform
to the following:
(a) All bars shall be enclosed by lateral ties, at least 10 mm φ in size for
longitudinal bars 32 mm φ or smaller, and at least 12 mm φ in size for 36
mm φ to 57 mm φ and bundled longitudinal bars.
(b) Vertical spacing of ties shall not exceed 16 longitudinal bar diameters or
48 tie diameters, or the least dimension of the compressionmembers.
(c) Ties shall be arranged such that every corner and alternate longitudinal
bar shall have lateral supportprovided by the corner of a tie with an
included angle not more than 135 deg. No vertical bar shall be farther than
150 mm clear on each side along the tie from such a laterally supported bar.
Where longitudinal bars are located around the perimeter of a circle, a
complete circular tie is allowed.
(d) The lowest tie in any storey shall be placed within one‐half the required
tie spacing from the top most horizontal reinforcement in the slab or footing
below. The uppermosttie in any storey shall be within one‐half the required
tie spacing from the lowest horizontal reinforcement in the slab or drop
panel above.
(e) Where beams or brackets provide concrete confinement at the top of the
column on all (four) sides, the top tie shall be within 75 mm of the lowest
horizontal reinforcement in the shallowest of such beams or brackets.
(f) Where anchor bolts are placed in the top of columns or pedestals, the
bolts shall be enclosed by lateral reinforcement that also surrounds at least
four vertical bars of the column or pedestal. The lateral reinforcement shall
be distributed within 125 mm of the top of the column or pedestal, and shall
consist of at least two 12 mm φ bars or three 10 mm φ bars.
(g) Where longitudinal bars are arranged in a circular pattern, individual
circular ties per specified spacing may be used.

9. Lateral reinforcement for flexural members:
Lateral reinforcement for flexural framing members subject to stress
reversals or to torsion at supports shall consist of closed ties, closed stirrups,
or spirals extending around the flexural reinforcement.
Shrinkage and temperature reinforcement:
Reinforcement for shrinkage and temperature stresses normal to flexural
reinforcement shall be provided in structural slabs where the flexural
reinforce-ment extends in one direction only.
Requirements for structural integrity:
In the detailing of reinforcement and connec-tions, members of a structure
shall be effectively tied together to improve integrity of the overall structure.