Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020) - page 28

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All timber or lumber forms shall be free from defects affecting the accuracy of shape, strength,
rigidity, water tightness and smoothness of the surface. Wooden forms shall be faced with smooth
sanded, exterior plywood, or equivalent as approved by the Engineer.

Timber and lumber shall be grade stamped and certified by a lumber grader or grading company
certified by an accredited certification agency meeting the approval and requirements of the United
Kingdom Timber Grading Committee or equivalent international timber grading certification
organization as approved by the Engineer.

Mill providing the lumber and timber shall provide a certificate providing the following grading
certification for the lumber/timber supplied. Certification shall include the following:

a. Name, address, name of manager and contact information of the mill

b. Name of the certified grader or grading organization and certifying standard organization.

c. Grading procedure and to what international standards the grading procedure complies with

(i.e. softwood visual strength grading to BS 4978: machine grading to BS EN 338; tropical
hardwood visual grading to BS 5756; and temperate hardwood visual grading to BS 5756)

d. Name and signature of the person doing the grading and their current certification or

qualification

e. Name and signature of the responsible mill official

f. Date the timber or lumber was graded at the mill

g. Grade (both visual and strength class), species, timber/lumber condition (wet, kiln dried, dry)

dimensions, and quantity of the timber or lumber

h. Source location of the timber or lumber

Each piece of timber used for structural work shall be grade stamped with the following information:

Grading certification organization logo

Standard reference, (i.e. BS EN 14081 for machine grading)

Grader and/or grader company reference (usually a number issued by the grading certification

organization to the grader when certified)

Timber condition (dry, kiln-dry or wet)

Species or species group

Grade (visual grading)

Strength class (machine grading)

Grading certification or approved for shipment stamp or tag shall not constitute final acceptance of
the material. Engineer may reject any or all of the timber or lumber that does not comply with these
specifications or has been damaged during storage, shipping, or upon delivery.

Contractor shall list in the form drawings the grade and class of wood required for the forms. Engineer
shall approve the manufacturer’s certification of structural properties. Wood panels stamped “shop”
or “shop cutting,” shall not be used.

Plyform, a plywood specifically designed and manufactured for concrete forming, is acceptable for
formwork. Plyform differs from conventional exterior plywood grades in strength and the exterior face
panels are sanded smooth and factory oiled. Contractor shall specify on the formwork drawings
whether Class 1, Class 2, or Structural I Plyform is required when used. Grades of plywood for
various form applications shall be as follows:

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Table 4-32: Plywood grades and formwork applications

Formwork application

Requirements to meet or exceed

Traffic and pedestrian barriers
that

will

not

receive

architectural surface treatment

APA* grade High Density Overlaid (HDO) Plyform Class I

APA* grades B-B Plyform Class I or B-C (Group I species)

The Contractor shall coat the form to prevent it from leaving joint
and grain marks on the surface

The Contractor shall submit for the Engineer

’s approval a 1.2 m

test

panel of concrete formed with the same plywood and coating as
proposed in the form drawings

Panel shall include 1 form joint along its centerline

Contractor

shall apply coating material per the manufacturer’s

instructions before applying chemical release agents

Other exposed surfaces (not traffic
and pedestrian barriers)

APA* grades B-B Plyform Class I or B-C (Group I series)

If one face is less than B quality, the B (or better) face shall contact
the concrete

Unexposed surfaces, including
barrier than will receive an
architectural finish

APA* grade CDX, provided the Contractor complies with required
stress and deflection limitations

*American Plywood Association (APA) grades provided for reference. Equivalent materials acceptable
with the Engineer

’s

approval.

Form joints on an exposed surface shall be in a horizontal or vertical plane. But in wingwalls, side
form joints shall be placed at right angles and parallel to the roadway grade.

Joints parallel to studs or joists shall be backed by a stud or joist. Joints at right angles to studs and
joists shall be backed by a stud or other backing the Engineer approves. Perpendicular backing is
not required if studs or joists are spaced:

•

230 mm or less on center and covered with 12 mm plywood

•

300 mm or less on center and covered with 20 mm plywood

Face grain of plywood shall run perpendicular to studs or joists unless shown otherwise on the
Contractor

’s formwork plans and approved by the Engineer. Proposals to deviate from the

perpendicular orientation shall be accompanied by supporting calculations of the stresses and
deflections.

Forming for all exposed curved surfaces shall follow the shape of the curve shown in the drawings
and shall not be chorded except as follows. On any retaining wall that follows a horizontal circular
curve, the wall stems may be a series of short chords if:

a. Chords within the panel are the same length, or otherwise as approved by the Engineer

b. Chords do not vary from a true curve by more than 12 mm at any point

c. All panel points are on the true curve

Where architectural treatment is required, the angle point for chords in wall stems shall fall at vertical
rustication joints. For exposed surfaces of walls, the Contractor shall build forms of plywood at least
20mm thick with studs no more than 300 mm on center. Engineer may approve exceptions, but
deflection of the plywood, studs, or wales shall never exceed 1⁄360 of the span (or 1⁄270 of the span
for unexposed surfaces).

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All form plywood shall be at least 12mm thick except on sharply curved surfaces. On sharp curves,
the Contractor may use 6mm plywood if it is backed firmly with heavier material.

Round columns or rounded pier shafts shall be formed with a self-supporting metal shell form or form
tube that leaves a smooth, nonspiralling surface. Wood forms are not permitted.

Metal forms shall not be used elsewhere unless the Engineer is satisfied with the surface and
approves in writing. Engineer may withdraw approval for metal forms at any time. If permitted to use
a combination of wood and metal in forms, the Contractor shall coat the forms so that the texture
produced by the wood matches that of the metal. Aluminum shall not be used for metal forms.

For design purposes, the Contractor shall assume that on vertical surfaces concrete exerts 732 kg-
force/m

of depth. However, when the depth is reached where the rate of placement controls the

pressure, the following table applies:

Table 4-33: Placement rates

Rate of Placing

(metres per hour)

Pressure (kg/cm

) for Temperature Of Concrete

15° C

21° C and above

0.6

0.23

0.18

0.9

0.31

0.27

1.2

0.35

0.30

1.5

0.40

0.34

1.8

0.44

0.37

2.1

0.48

0.40

2.4

0.52

0.43

2.7

0.57

0.46

3.0

0.61

0.49

4.6

0.81

0.63

Pressures in the above table have been increased to provide an allowance for the vibration and
impact.

4.6.2

Construction of Formwork

Formwork shall be constructed accurately to represent the shape of the concrete as detailed on the
Contract plans.  It shall be of suitable design and substantial construction and be approved by the
Engineer.  Contractor shall make any necessary adjustments to allow for shrinkage, settlement or
deflection  which  may  occur  during  construction  so  that  the  finished  concrete  sections  conform
accurately to the specified dimensions true to line, level and camber.

Contractor shall give the Engineer at least 24

hours’ notice of the Contractor’s intention to place the

concrete to enable the Engineer to inspect all aspects of the completed work. However, before
notifying the Engineer, the Contractor shall ensure that the work complies in all respects with these
standard specifications.

When  prefabricated  formwork,  shoring  or  scaffolding  units  are  used,  the  manufacturer's
recommendations  for  allowable  loads  may  be  followed  if  supported  by  test  reports  or  successful
experience records.  For materials which will experience substantial reuse, reduced allowable load
values may be required.

No accessory for supporting the formwork or staging shall be built into the permanent structure
except with the Engineer's approval.

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Formwork shall be constructed to provide completed concrete surfaces complying with the
tolerances specified therein and within these standard specifications.

Materials used in the construction of falsework and formwork shall be suitable for the purpose for
which they are required and be of such quality as to produce the specified standard of work. Type,
grade and condition of the material shall be subject to the Engineer's approval.

Timber boards shall be fixed with such openings between the individual boards that they will close
completely after the wetting which will precede the concreting.

As directed by the Engineer, Class C15 blinding concrete will be placed to a minimum depth of 100
mm in the foundation of footings of structures to provide a working platform and to protect the stability
of the foundation soils. Area shall be sufficient to provide support for formwork.

Forms for all surfaces which will not be completely enclosed or hidden below the permanent surfaces
of the ground, or for surfaces where plywood forms are not specified, shall be made of surfaced
lumber or material which will provide a surface at least equally satisfactory. Any lumber or material
which becomes warped or checked prior to placing of the concrete will be rejected.

Forms for all exposed surfaces shall be constructed with new plywood or metal on the face of the
form that will be in contact with the concrete. This form surface shall be maintained equal to the new
surfaces at all times as needed to produce the desired concrete surface. Engineer shall be the sole
judge as to when the form faces shall be replaced.

All exposed sharp edges shall be chamfered with triangular fillets not less than 20 mm by 20 mm to
prevent mortar runs and to preserve smooth, straight lines, unless otherwise directed by the
Engineer. Triangular fillets or chamfer strips shall be milled from clear, straight grain lumber and
shall be surfaced on all sides. Curved surfaces shall be formed of plywood, metal, or other suitable
material.

Form clamps or bolts shall be used to fasten forms.

Bolts  or  form  clamps  shall  be  positive  in  action and  shall  be  of  sufficient  strength  and  number  to
prevent spreading of the forms.  Lifting anchors may be installed in precast members.  Bolts, form
clamps and lifting anchors shall be of such type that they can be entirely removed or cut back 20
mm or more below the finished surface of the concrete, leaving no metal within 30 mm of the concrete
surface.  All forms for the outside surfaces shall be constructed with stiff wales at right angles to the
studs and all form clamps shall extend through and fasten such wales.

No concrete shall be deposited in the forms until all work connected with constructing the forms and
placing all reinforcing steel, ducts, and anchorages has been completed for the unit to be poured
and the Engineer has inspected said forms, reinforcing steel, ducts, or anchorages.

Openings shall be provided in forms to accommodate other work, including mechanical and electrical
work. Accurately place and securely support items required to be built into the forms.

Drainage holes and weep holes shall be constructed as detailed on the drawings. Forms for weep
holes shall be as approved by the Engineer.

Contractor shall install in the formwork required inserts, anchors, expansion joint elements, sleeves,
and other items specified under other sections of these specifications and shall coordinate
installation with other trades in the proper location of such items. Ends of conduits, piping and
sleeves embedded in concrete shall be closed with caps or plugs.

Tests on piping and other items which are required to be tested shall have been completed before
starting concrete placement.

If the Contractor uses metal forms, they shall be of a type which does not require the use of wire or
other ties that remain embedded in the concrete after the forms have been removed. Where ties
are necessary, bolts and rods shall be used, but they must be arranged so that when the forms are
removed no metal shall be within 30mm of any surface.

Where holes are boxed out in the concrete for the subsequent building-in of pipes, brackets, lagbolts
or other ironwork or details, the boxes shall become part of the formwork and shall be accurately set

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out and securely fixed. If the Contractor uses other methods for building in the above mentioned
ironwork or details, such methods shall be used only with the Engineer's prior approval, and such
approval shall in no way relieve the Contractor of his responsibility for the accuracy of the final
finished positions of such ironwork and details to be built in.

Openings for the inspection of the inside of the formwork and for the escape of water used for
washing out shall be formed so that they can be conveniently closed before placing of the concrete.

Shutters  shall  be  provided  for  all  slopes  exceeding  15  degrees  to  the  horizontal  to  enable  the
concrete to be properly placed.  Formwork shall be constructed so that the side shutters of members
can be removed without disturbing the soffit shutters and, if the Contractor wishes to leave some of
the props in place when the soffit shutters are removed, these props shall not be disturbed during
the striking.  Detailed arrangement of the props shall be submitted to the Engineer in advance for
his approval.

Before any concrete is placed in it, the formwork shall be cleaned of all sawdust shavings and dirt
and other debris washed out and all openings closed. Interior face of all formwork shall be carefully
coated with an approved non-staining preparation to prevent the adhesion of the concrete thereto.
This preparation must not be allowed to come into contact with the reinforcement and no organic oil
will be permitted to be used to coat the forms.

All formwork shall be inspected and approved by the Engineer before any concrete is placed in it,
and such approval shall not relieve the Contractor of his responsibility for the safety, accuracy or
efficiency of the work.

Use of permanent forms, of any material, that are proposed to remain in place at the completion of
construction will not be permitted unless otherwise specified in these specifications or in the project
particular specifications.

No load shall be applied to any part of a structure until the specified curing period has expired, after
which applied loading shall be allowed only when approved by the Engineer. Engineer's decision will
be based on the type of load to be applied, the age of the concrete, the magnitude of stress induced
and the propping of the structure.

Formwork shall be sufficiently rigid to maintain the forms in their correct position, shape and profile
and shall be of such tight construction that the concrete can be placed and compacted without undue
loss or leakage of the mortar component of the concrete.

Joints between contiguous formwork elements shall be of a tight fit and, where necessary, the joints
shall be caulked, taped or packed with a sealing gasket, all at no extra payment if undue leakage
occurs or can be expected. Paper, cloth or similar material shall not be used for this purpose.

Formwork construction shall permit accurate erection and easy stripping without shock, disturbance
or damage to the cast concrete. Where necessary, the formwork assembly shall permit the removal
or release of side forms independently of the soffit forms.

Metal supports, ties, hangers and accessories embedded in the concrete shall be removed to a
depth of not less than the cover specified for the reinforcement. No wire ties shall be used.

All external corners shall be chamfered by fillet strips being fixed into the corners of the formwork to
form 25mm x 25mm chamfers. Re-entrant angles need not be chamfered unless specified. Where
polystyrene or similar material, susceptible to damage is used, it shall be lined with a hard surface
on the side to be concreted. Hard material shall be sufficiently resilient to ensure that the required
quality of work can be achieved.

Where it is specified, all formwork ties shall be provided with recoverable truncated cones between
sleeve ends and formwork faces to ensure that sleeve ends are not exposed on concrete surfaces.
Cones shall have a minimum depth of 15 mm.

4.6.2.1

Drainage of Substructure

Contractor shall use weep holes and gravel backfill that complies with Table 2-4, Article 2.5.2.5 of
Chapter 2, Earthworks, for drain fill material behind retaining walls or minor structures. To maintain

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thorough drainage, weep holes shall be placed as low as possible. Weep holes shall be covered with
geotextile meeting the requirements of Table 2-7, Article 2.5.2.8 of Chapter 2, Class 1, before
backfilling. Geotextile shall have an apparent opening size (AOS) not greater than 0.180 mm and a
minimum water permittivity of 0.3 sec

-1

. Geotextile screening shall be bonded to the concrete with

an approved adhesive. Gravel backfill shall be placed and compacted as required in Section 2.7.3.
Additional tiling, French or rock drains, or other drainage devices shall be installed per the drawings.
If underdrains are not installed behind the wall, all backfill within 450 mm of weep holes shall comply
with Article 2.5.2.5 of Chapter 2. Unless the drawings require otherwise, all other backfill behind the
wall shall be structural backfill as specified in Article 2.5.2.4 of Chapter 2, Earthworks.

4.6.2.2

Formwork to Enclosed Surfaces

Formwork and boards shall be so arranged as to form a uniform and regular pattern in line with and
perpendicular  to  the  main  axis  of  the  member,  unless  otherwise  approved  or  directed  by  the
Engineer. Joints between contiguous members shall, after caulking, taping or sealing, be treated to
prevent blemishes, stains and undue marks from being imparted to the concrete surface. Bolt and
tie  positions  shall  be  so  arranged  that  they  conform  to  the  symmetry  of  the  formwork  panels  or
boards.  Bolt  and  rivet  heads  which  will  be  in  contact  with  the  formed  surface  shall  be  of  the
countersunk type and shall be treated to prevent marks from forming on the concrete surface.

Formwork at construction joints shall be braced to prevent steps from forming in the concrete
surfaces at the joints between successive stages of construction. Where moulding or recess strips
are specified, they shall be neatly butted or mitred.

4.6.2.3

Formwork for Open Joints

Requirements for formwork for open joints shall, unless otherwise specified, apply only to cases
where the distance between opposite concrete surfaces is equal to or less than 150 mm. Formwork
for open joints shall be constructed to produce a Class 1 surface finish to concealed surfaces or a
Class 2 surface finish corresponding to the in-plane surface finish of the bordering concrete surfaces.
Material used and construction of the formwork shall permit its complete removal to form the open
joint.

No solvent shall be used to remove formwork unless approved by the Engineer.

4.6.2.4

Openings and Wall Chases

Openings and wall chases shall be provided only where indicated on the drawings or as authorized
by the Engineer. Frames for openings shall be rigid and firmly secured in position to prevent their
moving. Temporary holes shall be so formed that they will not create an irregular pattern in relation
to the rest of the exposed formed concrete surface.

4.6.2.5

Slip-form Formwork

Equipment shall meet the requirements of Article 7.5.3.4 of Chapter 7, Incidental Construction. All
equipment shall be thoroughly tested and inspected before installation and shall be maintained in a
good working order throughout the entire slip-form operation. Contractor shall keep adequate back-
up equipment and quantities of materials on the site of the works to ensure that the slide casting can
proceed without interruption.

4.6.2.6

Fixed Formwork

Void formers shall be secured in position at regular intervals to prevent displacement and distortion
during concreting. Void formers shall be supported. Ties securing the void formers shall be attached
to the formwork. Void formers shall not be tied to or supported on the reinforcement.

Fibre-cement plates shall be supported so that the plate spans in the direction parallel to the
orientation of the asbestos fibres.

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Void formers used in permanent work shall be subject to the approval of the Engineer. Where void
formers  of  a  special  design  are  required,  details  thereof  will  be  specified.  Void  formers  shall  be
manufactured from material which will not leak, tear or be damaged during the course of construction
and  shall  be  of  such  tight  construction  as  to  prevent  undue  loss  of  the  mortar  component  of  the
concrete  through  leakage.  Units  shall  be  sufficiently  rigid  so  as  not  to  deform  during  handling  or
under the pressure of the wet concrete.

For mild-steel spiral-lock-formed void formers, the metal thickness shall be as follows, unless
otherwise specified:

a. Unbraced void formers

1. 0.6 mm for diameters of up to 600 mm

2. 0.8 mm for diameters exceeding 600 mm and up to 800 mm

3. 1.0 mm for diameters exceeding 800mm and up to 1000 mm.

b. Braced void formers

1. 0.6 mm for diameters of up to 800 mm

2. 0.8 mm for diameters exceeding 800 mm and up to 1000 mm

3. 1.0 mm for diameters exceeding 1000 mm and up to 1200 mm

4. 1.2 mm for diameters exceeding 1200 mm.

Thickness specified for braced void formers shall apply to formers internally braced with timber or
equivalent braces. Braces shall be at spacing not exceeding 2 m and not further than 1.0 m from the
end of each unit. Timber cross braces shall consist of members with cross-sectional dimensions of
at least 50 mm x 50 mm. All hollow void-former units shall be provided with a 12 mm diameter
drainage hole at each end.

4.6.2.7

Preparing the Formwork

Surfaces of forms which are to be in contact with plastic concrete shall be treated to ensure non-
adhesion of the concrete to the forms and easy release from the concrete during the stripping of the
formwork.

Release agents shall be applied strictly in accordance with the manufacturer's instructions, and every
precaution shall be taken to avoid the contamination of the reinforcement. In the selection of release
agents, due regard shall be given to the necessity for maintaining a uniform colour and appearance
throughout on the exposed concrete surfaces. Release agent shall not contain materials that could
affect bond of subsequent finishes or natural appearance of exposed concrete surfaces. Contractor
is responsible for using a release agent that is compatible with the proposed finish.

If  an  exposed  concrete  surface  will  be  sealed,  the  release  agent  shall  not  contain  silicone  resin.
Before applying the agent, the Contractor shall provide the Engineer a written statement from the
manufacturer  stating  whether  the  resin  in  the  base  material  is  silicone  or  nonsilicone.  Contractor
shall submit to the Engineer a sample of the release agent at least 14 working days before its use.
Approval or disapproval shall be based on laboratory test results.  Engineer may reject any forms
that will not produce a satisfactory surface.

Forms to be treated with a release agent shall be treated before placing reinforcing and embedded
items.  Contractor  shall  take  care  not  to  scuff  the  release  agent  when  placing  reinforcing  and
embedded items.  Scuffed areas shall be re-treated with the release agent, using care not to coat
reinforcing and embedded items. Holes and spalling within the slab surface from previous cast shall
be repaired and allowed to cure before the Contractor applies a new coat of releasing agent.  Before
the concrete is placed, all dirt and foreign matter shall be removed from the forms and the forms
shall be thoroughly wetted with water.

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4.6.2.8

Embedded Articles

Sleeves, pipes or conduits of any material shall be located so as not to impair unduly the strength of
the concrete. Articles embedded in concrete shall be as indicated on the drawings and as directed
by the Engineer.

Special care shall be taken to ensure that the articles are securely fixed in the correct position and
the Contractor shall at his own expense provide all necessary templates, temporary supports and
other equipment and labour required.

Articles to be embedded in concrete shall be clean and free from oil or foreign matter that would
weaken the bond of the concrete to these items.

Clear space between such embedded articles and any reinforcing steel shall be at least 40 mm or
the maximum size of the aggregate plus 5mm, whichever is the greater. Thickness of the concrete
cover over pipes and fittings shall be at least 25 mm. Ends of all ferrules used for bracing formwork
shall be neatly finished off to the details shown on the drawings. Where no details are given on the
drawings, ferrules shall be cut back to a depth of at least the specified cover, and the holes shall be
filled in with mortar and finished off flush with the concrete surface.

4.6.2.9

Formwork Accessories

Formwork accessories such as form ties, form anchors, form hangers, anchoring inserts, and similar
hardware shall be specifically identified in the formwork plans including the name and size of the
hardware, manufacturer, safe working load, and factor of safety. Grade of steel shall also be
indicated for threaded rods, coil rods, and similar hardware. Wire form ties and taper ties shall not
be used. Welding or clamping formwork accessories to reinforcing steel will not be allowed.

Table 4-34, from ACI 347R-88, provides minimum safety factors for formwork accessories. Hardware
proposed shall meet these minimum ultimate strength requirements or the manufacturer’s minimum
requirements, whichever provides the greater factor of safety. Contractor shall attach copies of the
manufacturer’s catalog cuts and/or test data of hardware proposed, to the formwork plans and submit
the formwork plans and calculations for review and approval by the Engineer.

Table 4-34: Minimum safety factors of formwork accessories

Accessory

Safety factor*

Type of construction

Form tie

2.0

All applications

Form anchor

2.0

Formwork supporting form mass and concrete pressures
only

Form anchor

3.0

Formwork supporting masses of forms, concrete,
construction live loads, and impact

Form hangers

2.0

All applications

Anchoring inserts

2.0

Placed in previous opposing concrete placement to act as
an anchor for form tie

*Safety factors are based on ultimate strength of the formwork accessory.

Bearing area of external holding devices shall be adequate to prevent excessive bearing stress on
form lumber. Form ties and form hangers shall be arranged symmetrically on the supporting
members to minimize twisting or rotation of the members. Form tie elongation shall not exceed the
allowable deflection of the wale or member that it supports. Inserts, bolts, coil rods, and other
fasteners shall be analyzed and designed for appropriately combined bending, shear, torsion, and
tension stresses.

Formwork shall not be attached to rebar or rebar cages installed per the drawings. However, the
Contractor may install additional reinforcing steel for formwork anchorage. Frictional resistance shall

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not be considered as contributing to the stability of any connection or connecting device, except
those designed as friction connectors such as U-bolt friction-type connectors.

Form anchors and anchoring inserts shall be designed considering concrete strength at time of
loading, available embedment, location in the member, and any other factors affecting their working
strength, and shall be installed in concrete per the manufactu

rer’s published requirements. Form

anchors and anchoring inserts embedded in previous concrete placements shall not be loaded until
the concrete has reached the required design strength. Required design strength of concrete for
loading of an anchor shall be shown in the formwork drawing if it is assumed that the anchor will be
loaded before the concrete has reached its 28-day strength.

Installation of permanent concrete inserts, such as form ties hangers, or embedded anchor
assemblies, shall permit removal of all metal to at least 12 mm below the concrete surface. Holes
shall be patched in accordance with Section 4.4.3. During removal of the outer unit, the bond
between the concrete and the inner unit or rod shall not be broken.

All corners except for footings, footing pedestals, and seals shall be bevelled 20 mm unless
otherwise shown on the drawings. All forms shall be as mortar-tight as possible with no water
standing in them as the concrete is placed.

4.6.3

Removal of Formwork

The Contractor shall be responsible for the safe removal of formwork. Contractor shall inform
Engineer in advance when the Contractor intends to strike any formwork.

Formwork shall not be removed before the concrete has attained sufficient strength to support its
own mass and any loads which may be imposed on it. The Engineer will decide, on the basis of post-
placement curing conditions, the exact number of hours that shall elapse before form removal. If the
Engineer does not specify otherwise, the Contractor may request to remove forms based on any one
of the criteria listed in the table below. Both compressive strength and time criteria must be met if
both are listed. Time shall be from the time of the last pour the forms support. In no case shall the
Contractor remove forms without the Engineer

’s approval.

Table 4-35: Removal of forms

Option

Form Use

Percent of

Specified

Minimum

Compressive

Strength

Time After

Last

Concrete

Placed

Walls, footings, traffic and pedestrian barriers,
and any side form not supporting the concrete
weight.

---

72 hours

Side forms not supporting the concrete weight

68 kg/cm

24 hours

Side forms, traffic barrier forms, and pedestrian
barrier  forms  made  of  steel  or  dense  plywood,
provided  an  approved  water  reducing  additive
was used.

68 kg/cm

24 hours

Side  forms  of  footings,  provided  a  curing
compound  was  applied  immediately  after
concrete  placement.  Compound  shall  not  be
applied to joint areas.

80 %

5 days

Other forms

70 %

24 hour**

*Strength shall be proved by test cubes per section 4.6.3.1.

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Option

Form Use

Percent of

Specified

Minimum

Compressive

Strength

Time After

Last

Concrete

Placed

** Time shall be 48 hours if the concrete mix included more than 15 % by weight GGBS or fly ash

Removal of formwork shall in all cases be supervised by an experienced foreman. All formwork shall
be removed without such check or vibration as may damage the concrete, and any work showing
signs of damage through premature loading shall be removed and entirely reconstructed.

All  formwork  shall  be  constructed  in  a  manner  to  facilitate  removal  of  formwork.  Forms  inside  of
hollow  structures  shall  be  removed  through  openings  shown  in  the  drawings  or  approved  by  the
Engineer. All materials removed shall become the property of the Contractor and shall be disposed
of by the Contractor at disposal areas as approved by the Owner.

Concrete surface shall not become dry during the entire curing period due to form removal or any
other cause.

4.6.3.1

Early Concrete Test Cube Breaks

Fabrication,  curing,  and  testing  of  early  cubes  shall  be  the  responsibility  of  the  Contractor.  Early
cubes are defined as all cubes tested in advance of the design age of 28 days whose purpose is to
determine  the  in-place  strength  of  concrete  in  a  structure  prior  to  applying  loads  or  stresses.
Contractor performed testing shall be performed by a testing laboratory whose equipment has been
calibrated  within  1  year  prior  to  testing,  and  testers  shall  be  either  ACI  certified  or  qualified  in
accordance with AASHTO R 18.

Concrete cubes shall be moulded, cured, and tested in accordance with Section 4.3.12 from concrete
last placed in the forms and representative of the quality of concrete placed in that pour.

Engineer may approve the use of cure boxes meeting the requirements of this test method. Special
cure boxes to enhance cylinder strength will not be allowed.

Number of early cube breaks shall be in accordance with the Contractor

’s need and as approved by

the Engineer. Contractor shall furnish the Engineer with all test results, proof of equipment
calibration, and tester’s certification. Test results will be reviewed and approved before any forms
are removed. Contractor shall not remove forms without the approval of the Engineer.

ORKS

Second Edition -SEP 2020

NDEX

Admixtures, 4-16
blast-furnace slag, 4-14
CDF. See controlled density fill
Coarse aggregate. See concrete aggregates
concrete acceptance, 4-37
Concrete admixtures. See admixtures
Concrete aggregates, 4-18
Concrete batching, 4-33
concrete classification, 4-24
concrete construction joints, 4-56
concrete curing, 4-42, 4-53
Concrete finishing, 4-55
concrete formwork construction, 4-75
concrete formwork removal, 4-81
concrete joint and crack sealing, 4-44
concrete mix design, 4-26
concrete nonconforming strength, 4-42
concrete placement, 4-48
concrete placement in seawater, 4-51
concrete precast curing, 4-61
concrete precast elements, 4-60
concrete precasting shop drawings, 4-60
concrete reinforcing, 4-60
concrete sampling and testing, 4-39

concrete slip-forms, 4-70
concrete vibration, 4-52
concrete waterproofing, 4-63
concrete waterstop placement, 4-59
Concrete water-to-cement ratio, 4-28
Controlled density fill, 4-28
Fine aggregate. See concrete aggregates
Fly ash, 4-12
grout, 4-29
hydraulic cement, 4-10
Low-alkali cement, 4-10
Metakaolin, 4-15
Microsilica fume, 4-15
Mortar, 4-29
Permeable concrete, 4-33
pervious concrete. See permeable concrete
Portland cement, 4-9
Sampling, 4-1
Shotcrete, 4-32
Tilt-up wall, 4-63
Water for concrete, 4-23
Waterstops, 4-48
water-tightness, 4-63

STANDARD CONSTRUCTION

SPECIFICATIONS

PART 1

ROADS

CHAPTER 5 - REINFORCING STEEL

DOCUMENT NO: TR-542-1

SECOND EDITION

SEPTEMBER 2020

Second Edition -SEP 2020

Chapter 5: Reinforcing Steel

ABLE OF

ONTENTS

Table of Contents............................................................................................................................. i

List of Tables .................................................................................................................................. iii

Reinforcing Steel ............................................................................................................... 5-1

5.1

General .......................................................................................................................... 5-1

5.2

Reference Standards and Codes ................................................................................... 5-1

5.3

Materials ........................................................................................................................ 5-4

5.3.1

Uncoated Reinforcement ........................................................................................ 5-4

5.3.2

Coated Reinforcement ............................................................................................ 5-4

5.3.2.1

Requirements for Coated Bars at Coating Applicator's Plant ........................... 5-5

5.3.2.2

Inspection ........................................................................................................ 5-7

5.3.2.3

Rejection ......................................................................................................... 5-7

5.3.2.4

Certification ...................................................................................................... 5-7

5.3.3

Stainless Steel Reinforcing Bars ............................................................................. 5-8

5.3.3.1

Binding Wire .................................................................................................... 5-8

5.3.3.2

Certificates and Tags ....................................................................................... 5-8

5.3.3.3

Bar Markings and Appearance ......................................................................... 5-8

5.3.3.4

Surface Contamination and Mechanical Defects .............................................. 5-9

5.3.4

Low-carbon, Chromium, Steel Reinforcing Bars...................................................... 5-9

5.3.4.1

Acceptance Requirements ............................................................................... 5-9

5.3.4.2

Identification .................................................................................................. 5-10

5.3.4.3

Independent Testing Laboratories ................................................................. 5-10

5.3.4.4

Test Reports .................................................................................................. 5-10

5.3.4.5

Product Sampling .......................................................................................... 5-10

5.3.4.6

Product Evaluation ......................................................................................... 5-11

5.3.4.7

Mechanical Properties ................................................................................... 5-11

5.3.4.8

Dimensions .................................................................................................... 5-11

5.3.4.9

Chemical Composition ................................................................................... 5-11

5.3.4.10

Quality Control ............................................................................................... 5-11

5.3.5

Bar Lists and Bending Diagrams ........................................................................... 5-12

5.4

Fabrication ................................................................................................................... 5-12

5.4.1

Cutting and Bending ............................................................................................. 5-12

5.4.2

Hooks and Bend Dimensions ................................................................................ 5-12

5.4.3

Mill Test Reports ................................................................................................... 5-13

5.4.4

Identification ......................................................................................................... 5-13

5.5

Application Methods..................................................................................................... 5-13

5.5.1

Handling and Storing Reinforcement Steel ........................................................... 5-13

5.5.1.1

Handling Uncoated Bars ................................................................................ 5-13

5.5.1.2

Handling Epoxy-coated Bars.......................................................................... 5-13

5.5.2

Placing and Fastening Reinforcement Steel ......................................................... 5-14

5.5.2.1

Support Systems for Reinforcing Steel .......................................................... 5-14

5.5.2.2

Precast Concrete Blocks ................................................................................ 5-14

5.5.2.3

Wire Bar Supports ......................................................................................... 5-14

5.5.2.4

Adjustments ................................................................................................... 5-14

5.5.2.5

Repairing Damaged Epoxy Coating ............................................................... 5-15

5.5.3

Minimum Test Procurement .................................................................................. 5-15

5.5.4

Splicing of Bars ..................................................................................................... 5-16

5.5.4.1

Lap Splices .................................................................................................... 5-16

5.5.4.2

Welded Splices .............................................................................................. 5-16

5.5.4.3

Mechanical Splices ........................................................................................ 5-17

5.5.4.4

Splicing of Welded Wire Fabric ...................................................................... 5-17

TEEL

Second Edition -SEP 2020

5.5.5

Substitutions ......................................................................................................... 5-17

5.5.6

Calculated Weights ............................................................................................... 5-17

Index 5-20

TEEL

Second Edition -SEP 2020

IST OF

ABLES

Table 5-1: Designations and titles for AASHTO and ASTM standards that apply to reinforcing steel
works ........................................................................................................................................... 5-2

Table 5-2: Designations and titles for BS, and BS EN standards that apply to reinforcing steel works
.................................................................................................................................................... 5-3

Table 5-3: Mandrel diameters for evaluation of epoxy-coated test bars ........................................ 5-6

Table 5-4: Reinforcing bars - nominal weights and areas ........................................................... 5-17

Table 5-5: Standard wire reinforcement - nominal weights and areas ........................................ 5-18

TEEL

REINFORCING STEEL

This work shall consist of furnishing and placing concrete reinforcing steel in accordance with these
Specifications and in conformity with the Contract Documents.

5.1

General

Unless otherwise specified in the Contract documents, all reinforcement steel bars shall be grade 60
(grade 420) uncoated deformed billet steel that meets the requirements of the American Association
of State Highway and Transportation Officials (AASHTO) and the American Society for Testing and
Materials (ASTM), as outlined in Standard Specification for Deformed and Plain Billet-Steel Bars for
Concrete Reinforcement (AASHTO M 31M/M 31-10 (2011)) and (ASTM A615 / A615M - 12). Type
2 deformed bars to BS 4449:2005+A2:2009 grade B500B may be proposed as an alternative.

When coated reinforcement is specified in the Contract documents, coated steel bars shall comply
with requirements of AASHTO and ASTM, as outlined in

Standard Specification for Epoxy-Coated

Reinforcing Bars: Materials and Coating

Requirements (AASHTO M 284M/M 284-09) and (ASTM A

775/A 775M-07b), or Stand

ard Specification for Fabrication and Jobsite Handling of Epoxy-Coated

Steel Reinforcing Bars

(AASHTO M 317M/M 317-03 (2007)) and (ASTM D3963 / D3963M -

01(2007)). Coated steel wire and welded fabric, as appropriate and as specified in this chapter, shall
comply with requirements outlined in

Standard Specification for Epoxy-Coated Steel Wire and

Welded Wire Reinforcement

(ASTM A884 / A884M - 12).

In post-tensioned members, spirals, or wire mesh behind anchorages, spiral reinforcement steel
shall comply with the requirements of

ASTM’s

Standard Specification for Steel Wire, Plain, for

Concrete Reinforcement

(ASTM A82 / A82M - 07).

In reinforced concrete compression members, spiral reinforcement shall be grade 60 (grade 420) as
defined in ASTM A615 / A615M

– 12 (AASHTO M 31M/M 31-10 (2011)).

The Contractor shall furnish, place and test reinforcing steel in accordance with these specifications
and in compliance with AASHTO/ ASTM or BS standards. Where reinforcing steel are manufactured,
fabricated, placed and tested by other standards not included in this chapter, products conforming
to equivalent or higher standards may be acceptable if proven to be suitable.

5.2

Reference Standards and Codes

Standards and codes for reinforcing steel shall be as specified in these specifications, in the Contract
documents, if any, and the following, in their latest edition.

AASHTO LRFD

American Association of State Highway and Transportation Officials - Load

and Resistance Factor Design, Bridge Construction Specifications;

AASHTO LRFD

American Association of State Highway and Transportation Officials - Load

and

Resistance Factor Design, Bridge Design Specifications;

AASHTO

Standard Specifications for Transportation Materials and Methods of

Sampling and Testing;

ACI

American Concrete Institute;

ACI 315-99

Details and Detailing of Concrete Reinforcement;

ACI SP-66(04)

ACI Detailing Manual-2004;

ADQCC (TR-516)

Road Structures Design Manual;

AISI

American Iron and Steel Institute;

ASTM

American Society for Testing and Materials;

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