Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 2 - ROAD STRUCTURES, 2020)

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-79

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

•

Details and locations of all other items to be embedded in the segments, such as inserts,

lifting devices, and post-tensioning hardware, shall be shown.

•

Prestressing details shall include sizes and properties of tendons, anchorages, plates,

assemblies, and stressing equipment

— as well as details of the stressing procedure and

stressing sequence, details and locations of all couplers, and additional reinforcement
necessary to resist anchor block stresses.

•

A table giving jacking sequence, jacking forces, and initial elongation of each tendon at each

stage of erection for all post-tensioning.

•

A table showing elevations and geometry to be used in positioning the forms for the next

segment to be cast.

•

Graphs, charts, or tables showing the theoretical location of each segment, as erected or

placed, shall be furnished to the Engineer for use in checking the erection of the
superstructure. Detailed procedures for making geometry corrections shall be described.

•

Details of tie-down tendons and temporary and permanent bearing assemblies as required.

•

Details of grouting equipment, grout mix design, method of mixing, and placing grout shall be

provided.

21.20.4

Forms

Shop drawings shall be submitted for forms and form travellers, as required by the Contract
documents.

In addition to the requirements of the Contract documents, the forms used to cast the concrete
segments shall be capable of the following:

•

Match-casting for precast segmental construction.

•

Producing the segments within the tolerances permitted.

•

Accommodating block outs, openings, and protrusions.

•

Adjusting to changes in segment geometry as shown in the Contract documents, or for

correcting previous minor casting errors to prevent accumulations.

•

Stripping without damage to the concrete.

•

Providing a tight, leak-proof joining to the previous segment.

Bulkheads must be capable of connecting the ducts in a manner to hold their position and prevent
intrusion of grout.

Where sections of forms are to be joined on the exterior face of the segment, an offset in excess of
1.5 mm for flat surfaces and 3 mm for corners and bends shall not be permitted. Offsets between
adjacent matching faces of cast-in-place segments shall not exceed 6 mm.

Forms  shall  not  be  removed  until  the  concrete  has  attained  the  release  strength  specified  in  the
Contract  documents,  as  evidenced  by  test  cubes  made  and  cured  in  the  same  manner  as  the
segment.  Alternatively,  maturity  metres  or  instrument  control  cubes  may  be  used  to  evaluate  the
strength of the concrete in the segment. Care shall be exercised in removing the forms to prevent
spalling and chipping of the concrete.

21.20.4.1 Forms for Precast Segmental Construction

All side, bottom, inside, and header forms for precast segmental construction shall be constructed
of steel unless use of other materials is approved by the Engineer.

Forms shall be of sufficient thickness, with adequate external bracing and stiffeners, and shall be
sufficiently anchored to withstand the forces due to placement and vibration of concrete. Internal
bracing and holding devices in forms shall be limited to stay bolts in webs that can be removed from
the concrete surface to permit patching following form removal. Joints shall be designed and
maintained for mortar tightness.

Form grades and alignments shall be checked each time they are set and shall be maintained during
the casting of concrete. Slab finish grades will be checked after the concrete is in place.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-80

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Metal forms shall be reasonably free from rust, grease, or other foreign materials. All forms shall be
cleaned thoroughly prior to each casting operation. End headers shall be maintained to provide a
smooth casting surface.

Wood forms may be used on the cast-in-place longitudinal and transverse closure strips.

All form surfaces for casting members shall be constructed and maintained to provide segment
tolerances in accordance with Section 21.20.2, Segmental Bridge Tolerances.

The faces of all forms, other than end headers, shall be properly cleaned and treated with form oil
or other bond-breaking coating prior to placing concrete. Bond-breaking material between segments
and headers shall be provided in accordance with Article 21.20.7.2, Separation of Match-cast
Segments. Oil or other materials used for this purpose shall be of a consistency and composition to
facilitate form removal. Materials that appreciably stain or react with the concrete shall not be
constructed to facilitate segment removal without damage to the concrete.

21.20.5

Permanent Bearings

This work shall furnish all materials, fabrication, and installation of the permanent bearings, as shown
in the Contract plans, as herein specified conforming to Chapter 25, Bearing Devices, and as
directed by the Engineer.

Bearings shall be fabricated in conformance with the Contract plans, except as otherwise and
specifically approved by the Engineer.

Prior to approval of the bearings to be used, the Contractor shall submit a certification by the
Manufacturer stating that it and the accessory items meet the requirements set forth. This shall not
constitute a waiver on the part of the Owner of any requirements with respect to samples and
sampling, and the right is retained to perform any of the tests specified or such test deemed by the
Engineer as necessary to qualify the material.

Installation  instructions  shall  be  obtained  by  the  Contractor  from  the  Supplier  of  the  bearing
assemblies  and  shall  comply  with  the  procedures  specified  in  the  installation  of  the  bearing  and
Chapter  25,  Bearing  Devices.  Shop  drawings  shall  be  submitted  to  the  Engineer  for  approval  in
accordance  with  the  provisions  of  the  section  of  these  Standard  Specifications  applicable  to  the
bearing being provided. Adequacy of the design and installation details shall meet with the approval
of the Engineer, whose decision shall be final.

21.20.6

Special Provisions for cast-in-place Segmental Construction

The Contract plans shall be prepared on the assumption that the superstructure will be constructed
by a selected method of cast-in-place reinforced-concrete segmental construction. Alternate
construction methods may be permitted in accordance with the Contract documents.

21.20.6.1 Forming System

In addition to the submittals required in Section 21.20.3, Shop Drawings and design calculations for
construction procedures, the following computations and working drawings shall be submitted for
the Engineer’s review and for compliance with the Contract documents:

•

Complete details and computations for the forms and form support system, including

maximum loadings and stresses created in the completed segments due to equipment forms
and concrete placement. Design of form support system shall include adequate allowances
for impact loadings which may occur during concrete placement and advancement of forming
system.

•

Computations of deflection of the forming system during concrete placement.

•

Details for temporary supports and tie-downs as needed to stabilize the cantilevers during

construction.

•

Detailed step-by-step procedures for concrete placement, stressing and advancing the form

support system, and adjusting the system for calculated deflection.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-81

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

•

Detailed procedures for fixing the cantilever ends against changes in position or rotation of

one cantilever relative to the other during and following placement of concrete for the closure
between the cantilevers.

In every stage of construction, the stability of the partially completed structure is a major concern.
Therefore, the Contractor shall evaluate the stability of partial structures to avoid any collapse due
to various combination of loads, including construction, wind loading, and vibration from equipment.

21.20.6.2 Superstructure Construction

This work shall consist of setting temporary bearings, if applicable; casting segments in place; and
setting the superstructure on permanent bearings.

Complete details and description of the methods, arrangements, and equipment shall be submitted
by the Contractor for t

he Engineer’s approval before superstructure construction is started.

Chosen  construction  methods  shall  include  casting  of  the  segments,  methods  of  the  tie-down  of
superstructures during cantilever erection, and methods of application of all temporary forces to be
used  for  adjusting  horizontal  and  vertical  alignments  and  to  place  the  structure  on  permanent
bearings.  This  shall  also  include  control  methods  to  ensure  the  accuracy  of  alignment  of  the
completed superstructure.

Work  equipment  includes  all  machinery,  devices,  labour,  and  materials  that  are  to  be  used  for
erection but shall not become a permanent part of the completed superstructure. Equipment must
not be operated from or placed upon any part of erected superstructure at any stage of construction
other  than  that  which  specifically  meets  the  requirement  of  total  working  load  per  segment,  as
allowed  by  the  Contract  documents,  or  as  approved  by  the  Engineer.  This  includes  the  post-
tensioning hardware; jointing, jacking, and grouting equipment; and personnel and materials of any
kind.

In addition to segment unbalanced loads that are permitted for the construction method, a (4.8 × 10

MPa) load is permissible and shall include personnel, miscellaneous equipment, and stored

material. It shall be the Contractor's responsibility to ensure that this allowable load is not exceeded.

Stressing may be performed in accordance with the following schedule:

•

Fifty percent of the post-tensioning force may be applied when field cured compression cubes

indicate the compressive strength of the segment concrete is 17.2 MPa, and 18 hours have
elapsed after completion of concrete placement.

•

Form support system may be released and advanced when 50 percent of the post-tensioning

stress has been applied.

•

Transverse stressing shall be staged to avoid exceeding the allowable stresses in the top

slab.

•

Tendons shall be fully tensioned prior to placement of concrete for the next segment, except

the transverse tendon nearest the segment to be constructed. That tendon shall be stressed
to 50 percent, and then stressed the remainder when tendons in the new segment are
stressed. Form support systems shall be designed to avoid overstressing the top slab in the
area of the partially stressed tendon.

Construction joints shall be limited to locations shown in the Contract documents or as approved, in
advance, by the Engineer. All construction joints shall be thoroughly cleaned of laitance and foreign
material prior to placing concrete for the abutting section.

Surface of the segment joints shall be prepared in accordance with the Contract documents
immediately prior to placement of concrete for the next segment.

For placement of closure concrete between cantilevers, the cantilevers shall be fixed to prevent
rotation or movement of one cantilever relative to the other. Systems for locking the cantilevers and
forming for the closure and the procedure for placing the concrete for the closure shall be such that
the concrete after the initial set shall not be subjected to tension that could cause cracking.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-82

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

A construction schedule or check list that shows the chronological order of every phase and stage
of erection and construction of the superstructure shall be submitted by the Contractor. Additionally,
the Contractor shall prepare a table of elevations and alignments required at each stage of erection,
as required by the Contract documents, at the check points listed below, or an alternative at the
Contractor's option, and submit the same to the Engineer.

•

One of the lowest corners at the top surface of any temporary bearing pads to be used as

datum during erection and to establish a reference point with the actual elevations and
alignment required of the permanently positioned superstructure.

•

All four corners and centreline (at segment faces) of top slab of pier segments to establish

grade and crown.

•

Two points on the longitudinal centreline of each pier segment, one on each edge, to

establish alignment.

•

One point on the longitudinal centreline and at least one corner of each segment along every

joint between cast-in-place segments to establish elevations and alignment at every stage of
erection.

Temporary bearing pads, if applicable, at the piers shall be carefully placed. Surfaces tops of these
pads shall have the correct elevations, alignments, and slopes

— as required by the Contract plans

and so established by the provisions above for temporary bearing pads. Shims may be used
underneath the pads to accomplish accuracy. Measures to hold temporary bearing pads in position
while the pier segment is being cast shall be devised and provided by the Contractor.

Elevations and alignment of the structure shall be checked by the Contractor at every stage of
construction, in accordance with the geometry control plan submitted in accordance with the
provisions of Section 21.20.1, Geometry Control, and shall maintain a record of all these checks and
of all adjustments and corrections made.

21.20.7

Special Provisions for Precast Concrete Segmental
Construction

Superstructure erections shall be executed by the method designed and detailed in the Contract
documents or by an alternate method submitted by the Contractor. Alternate erection methods may
be permitted, when specified in the Contract documents.

When required by the  Contract documents, the stressing system  and all reinforcement and lifting
details shall be successfully demonstrated on a segment designated in the Contract documents prior
to  casting  any  permanent  segments.  The  segment  shall  conform  to  the  size  and  configuration
required by the Contract documents, including post-tensioning anchorage pockets, reinforcing steel,
concrete,  and  conduits,  including  curvature  and  spacing.  Tendons  designated  in  the  Contract
documents for this test shall be stressed to the forces shown. No additional payment shall be made
for this test.

Casting beds and forms shall be structurally adequate to support the segments without settlement
or distortion. Casting beds shall be designed for a method and the hardware needed to adjust and
maintain grade and alignment. Details for hardware and adjustment procedures shall be included in
the Contract plans and specifications for the casting bed.

Grading of the soffit form and the top portion of each segment shall take into consideration the
relative position of the member in the structure.

After the first segment of each unit is cast, all succeeding segments shall be cast against previously
cast segments to ensure complete bearing and proper alignment on all mating surfaces.

Anchorage systems shall permit tendons to be inserted in the member after erection of segments.

Tendon couplers shall be used only at locations specifically shown in the Contract documents or
when approved by the Engineer. Not more than 50 percent of the tendons shall be coupled at anyone
section. When temporary external tendons are required by the Contract documents, the tendons and
anchors shall be in a protective enclosure capable of protecting the tendons from damage by erection
equipment and capable of confining a strand or bar tendon that breaks or otherwise releases tension

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-83

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

rapidly during or after tensioning and anchorage. Protective enclosure proposals shall be submitted
to the Engineer for approval.

Care shall be taken to ensure that deformations of match-cast segments due to thermal gradients
caused by the heat of hydration of the new cast concrete do not exceed, at the time of initial set of
the new concrete, 0.8 mm for a single segment or 19 mm cumulative for an entire span. These
deformations shall be prevented by properly protecting both the match-cast and new cast segments
in an isothermal enclosure or with curing blankets and plastic sheeting. The design gradient in the

AASHTO LRFD Bridge Design Specifications

can assist the Contractor in determining to what extent

this type of deformation will occur and if additional protection of the match-cast segment is
necessary.

21.20.7.1 Fabrication

Reinforcing steel shall be fabricated and placed according to the Contract documents. Any conflict
or interference with the proper location of ducts, reinforcing, or block outs shall be promptly resolved
and corrections made

— as directed by the Engineer. No reinforcing steel shall be cut and removed

to permit proper alignment of stressing conduits. Any bar that cannot be fabricated to clear the post-
tensioning duct shall be replaced by additional bars with adequate lap lengths and shall be submitted
to the Engineer for approval.

All segments shall be marked on the inside with a unique identification at the time of form removal.
This identification shall be used to identify each segment on shop drawings, post-tensioning details
and calculations, and any other document pertaining to the fabrication and erection of precast
concrete segments.

Positive means of holding the conduit in its correct position shall be provided in all cases and shall
be indicated on the working drawings submitted for approval. The conduit shall be supported at
intervals as specified in Chapter 22, Prestressing Systems, Section 22.8.4.2, Placement of Ducts,
or as shown in the Contract documents, and shall be securely fastened to prevent movement during
placement of concrete.

21.20.7.2 Separation of Match-cast Segments

Equipment to be used for uniform separation of match-cast segments shall be provided by the
Contractor without damage. Methods, as well as details of the equipment to be used for separating
match-cast segments, shall be included in the shop drawings. A bond-breaking material shall be
used on the web and flanges of the previously cast segment to facilitate separation of segments.
Bond-breaking materials shall be used to break the bond of concrete between the face of previously
cast segments and a newly cast segment, as well as the end headers, when required. Bond breakers
shall consist of flax soap and talc, or another material approved by the Engineer. A demonstration
shall be performed on a 600-mm by 1,200-mm specimen, prior to the casting of segments, to prove
the adequacy of the material. Materials shall not be injurious to the concrete and shall permit removal
of a segment without pullouts caused by adhesion of the concrete.

21.20.7.3 Handling and Erection of Segments

Proper handling, lifting, storing, transporting, and erection of all segments shall be the responsibility
of the Contractor so that they may be placed in the structure without damage.

Segments shall be maintained in an upright position at all times and shall be stored, lifted, or moved
in a manner to prevent torsion and other undue stress. Members shall be lifted, hoisted, or stored
with lifting devices approved on the shop drawings or by another method approved by the Engineer,
in writing.

Segments shall not be moved from the casting yard until all curing and strength requirements have
been attained and shall be supported in a manner that will minimize warping.

A full-scale test of the lifting and temporary holding hardware shall be performed to demonstrate the
adequacy of this equipment prior to beginning any erection of the segments.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-84

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

21.20.8

Special Provisions for Incremental Launching

Structures built by the incremental launching method shall comply with the provisions of Section
21.20.3, Shop Drawings and design calculations for construction procedures, and the additional
provisions of the following section.

21.20.8.1 Casting of Segments

Construction of incrementally launched bridges shall be based on a weekly cycle for the construction
of each segment. When the bottom flange and webs, or portions of webs, of segments are cast first
and the top flange afterward, the time between concrete placements shall not exceed three days.

21.20.8.2 Geometric Tolerances

The following tolerances shall not be exceeded in the region of the sliding surfaces:

•

In the Forms:

•

Vertical deviations in longitudinal and transverse direction: ±0.8 mm

•

Horizontal deviation at the outside of webs: ±1.5 mm

•

On the Launching Bearings:

•

Vertical: Longitudinally between piers: ±1.5 mm

•

Transversely between bearings: ±0.8 mm

•

Horizontal: Deviation of lateral guides: ±1.5 mm

21.20.8.3 Launching Force

Launching forces shall be monitored continuously and checked against the theoretical value. A
friction value between 0 percent and 4 percent shall be maintained. Grease may be used on the
sliding plates, as required to maintain friction values. Friction values of zero shall be considered in
calculation of the force required to hold back a structure launched on a negative gradient.

21.20.8.4 Pier Monitoring

Pier top deflection shall be continuously monitored. Monitoring devices that automatically switch off
the launching equipment in case the permissible pier deflections are exceeded are recommended.
Communication between each sliding bearing and the launching equipment shall be provided.

At regular intervals, the Contractor shall check the correct level of all sliding bearings. Shim plates
shall be kept in stock for all sliding bearings to compensate for pier settlements, if any.

21.20.9

Defects and Breakage

Failure of individual wires in a seven-wire strand is acceptable with the approval of the Engineer,
provided the total area of wire failure is not more than 2 percent of the total cross-sectional area of
the tendon.

Minor or non-structural cracks or checks on the surface of the member which, as determined by the
Engineer, do not extend to the plane of the nearest reinforcement, will be acceptable unless they
are numerous and extensive. Diagonal cracks that indicate damage from torsion, longitudinal cracks
that follow stressing tendons, or any cracks that extend into the plane of the reinforcing steel or
prestressed tendons shall be subject to a structural review prior to acceptance. If found acceptable,
the cracks shall be repaired by veeing out 6 mm deep and wide and sealing with epoxy or shall be
repaired by epoxy injection.

Prior  to  the  start  of  segment  fabrication,  the  Contractor  shall  repair  minor  breakage,  spalling,  or
honeycombing not more than 25 mm deep in accordance with an established repair procedure, as
approved by the Engineer. Major breakage or honeycombing in excess of that specified herein shall
be subject to structural review. If  the established repair procedure is found to be satisfactory, the
Contractor  shall  repair  these  areas  as  directed  by  the  Engineer.  Breakage,  spalling,  or

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-85

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

honeycombing on any mating surface found to be acceptable shall be repaired and the concrete
cured prior to casting the mating segment

— if such segment has not yet been cast.

21.21

Architectural Surface Treatment for Tunnel and
Underpass Walls

The Contractor shall furnish and install the architectural surface treatment on the tunnel and
underpass walls and any associated structures as shown on the Contract plans, as specified herein,
or as directed by the Engineer.

The Engineer shall provide the Contractor with conceptual design details and the Contractor shall
develop complete design details and shop drawings for the Owner

’s review and approval.

21.21.1

Types of Surface Treatment

The Contractor shall furnish and install surface treatments of the types specified herein, as shown
on the Contract plans, or as directed by the Engineer.

The specific type of finishing technique and materials to be applied at the various structures may be
subject to change and the Contractor shall take account of this likelihood as no additional
reimbursement shall be made for such revisions. All finishes shall be of the highest quality, and the
Contractor shall provide samples and mock-up for all the types of finishes on the Project for the
Engineer’s approval. The surface treatment for each structure shall be one or more of the following:

1.  Ceramic wall tiles
2.  Textured concrete finish
3.  Painting of exposed concrete
4.  Fire protection boards

All concrete surfaces not in contact with soil and not shown on the Contract plans to be painted, shall
be sealed as per the requirements of Section 29.6 of Chapter 29, Miscellaneous Items for Structures,
of these standard specifications.

21.21.1.1 Ceramic Wall Tiles

Ceramic wall tiles shall be clay body, heavy duty type with nominal sizes as noted on the Drawings,
and thickness not less than 6mm. The tiles shall have reasonably flat matte surface and bondable
back and shall be UV, and acid/alkali resistant.

Ceramic wall tiles shall contain a wide range of shades and colours matching with the colours shown
on the approved design or pattern. The final shades and colours shall be selected by the Engineer
and approved by the Owner. The surface finish of all the selected shades and colours shall be
uniform and consistent unless otherwise required by the Engineer.

Where required, the Contractor shall cut tiles to achieve the required design or pattern approved by
the Owner. Cutting shall be by water jet cutting or another approved technique.

Final colours shall be selected by the Engineer, installed at locations indicated on the Contract plans
and as directed by the Engineer. Five full size sample units of each of the selected colours and
representative of the anticipated shade range of each colour shall be submitted to the Engineer for
approval. Upon delivery, all tiles furnished shall be inspected by the Engineer and shall match the
previously approved samples within the approved shade range. Tiles outside the approved shade
range will be rejected, removed from the job site, and replaced with approved material at no
additional cost to the Owner.

Sampling, Inspection and Test Procedures for Tiling

In addition to the visual colour inspection specified above, the sampling, inspection, and test
procedures and the basis for acceptance and rejection shall be as specified hereinafter.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-86

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

1. Samples

Samples of tile for test purposes shall be selected by the testing laboratory's inspector at the place
of manufacture. Each sample shall consist of 5 tiles taken at random from each manufactured lot of
8,000 units, furnished at the Contractor's expense. No tile from any lot shall be shipped from the
point of manufacture until the samples from that lot have successfully passed all tests. If a sample
fails to meet the requirements and a maximum of two additional samples also fail, the lot shall be
rejected. Tile which has been rejected at the place of manufacture shall not be shipped to the work
site, and any tile which may be rejected at the work site shall be promptly removed from the site.
Such rejected tiles shall not be resubmitted for inspection or tests.

2. Certification of Tests

Tests shall be performed by an engineer approved independent testing laboratory at the Contractor's
expense. The Contractor shall submit duplicate certified reports to the Engineer. Such test reports
shall clearly identify the tile tested and the boxed tiles represented by the tile tested, which shall be
clearly identified.

3. Inspection

Tile  samples  shall  be  carefully  inspected  for  compliance  with  dimension  requirements  specified
herein. The backs shall be free from glaze, glaze sheen or film. The edges shall be reasonably free
from a glaze coating and shall not have drops or globules exceeding 0.4mm thickness. The body
shall be free from concave warpage exceeding 0.2 of one percent of the diagonal of the rectangle
and shall be free from convex warpage 0.3 of one percent of the diagonal. They shall be free from
wedging  or  crooked  edges  exceeding  0.5  of  one  percent.  Tiles  shall  also  be  free  from  other
imperfections such as pressing cracks, dents, swelling, and chipping. The glazed surface shall be
smooth,  easily  cleaned,  and  free  from  all  imperfections  or  defects  such  as  waviness,  pinholes,
specks,  spots,  blisters,  feathering,  crawling,  crazing,  scumming,  discolouration,  or  sanding  to  an
extent which would affect the appearance of the tile.

4. Absorption Test

A sample lot of tiles shall be dried in an oven for 2 hours at 100°C, cooled to room temperature, and
weighed separately on a scale sensitive to 0.5 gram. The dry samples shall then be placed in water
at a temperature of 15 to 30°C. The tile samples shall be boiled in water for two hours and permitted
to cool gradually to within 15 to 27°C. The samples shall be removed from the water 24 hours after
the initial immersion, their surfaces wiped dry with a clean damp cloth, and the tiles quickly weighed
separately. The percent absorption of each sample shall be calculated on the basis of its dry weight.
The average water absorption of the 5 samples tested shall not exceed 2 percent. The water
absorption of any individual sample shall not exceed 2.75 percent.

5. Crazing Test

An autoclave with sufficient capacity to contain a sample lot of tiles shall be used. The apparatus
shall be equipped with a safety valve, blow-off valve, pressure gauge whose accuracy is within 2
percent of the scale range, and a burner of sufficient capacity to ensure a constant steam pressure.
A sufficient amount of water shall be placed in the autoclave so that after a one-hour test at 1.38
MPa steam pressure, a slight excess of water will remain. A sample lot of tiles shall be loosely placed
on edge in a suitable wire container above the water line within the autoclave at room temperature.
The autoclave head shall be securely fastened in place. The water in the bottom of the autoclave
shall be heated from an external source. The blow-off valve shall be kept open until steam begins to
escape, thereby expelling most of the air. After closing the blow-off valve, the water shall be kept
boiling and the steam pressure increased at a uniform rate until 1.38 MPa of pressure is reached
within a period not exceeding one hour. Sufficient heat shall be applied to maintain constant steam
pressure of 1.38 MPa for an additional hour. The burner shall be shut off and the steam pressure
immediately released by opening the blow-off valve. The autoclave head shall be loosened but not
removed until the samples have cooled slowly to room temperature in a period not less than one
hour. The samples shall then be removed and a liquid dye rubbed on their surfaces to aid in the

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-87

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

detection and examination for failure. After being subjected to 5 consecutive cycles of the foregoing
crazing test, the sample lot tested shall show no crazing, chipping, spalling, or cracking of either the
body or glaze. The glazed surface of the tile shall show no permanent clouding, dulling, or pitting.
Slight dull streaks will be permitted, provided they do not comprise more than 20 percent of the
glazed surface area.

6. Thermal Shock Test

A sample of tiles shall be placed in an oven at room temperature. The temperature within the oven
shall be uniformly raised to 110

C, in a period of one hour after which the tiles shall be removed

from the oven and immediately plunged into a mixture of ice and water having a temperature of not
more than two degrees C. At the end of 10 minutes the tiles shall be removed from the water mixture
and a liquid dye applied upon the glazed surfaces and bodies to aid in the detection and examination
of failures. After being subjected to 5 consecutive cycles of the foregoing thermal shock test, the
sample lot shall show no crazing, chipping, spalling, or cracking of either the body or glaze.

7. Weather Test

A sample lot of tiles shall be placed in water at room temperature. The water shall then be boiled for
a period of 2 hours and permitted to cool gradually to room temperature. The tiles shall then be
removed from the water and their surfaces wiped dry with a clean damp cloth. Immediately thereafter
they shall be placed in a freezing chamber (not immersed in water) for a period of 4 hours. The
freezing chamber shall be maintained at a temperature of -12

C. The tiles shall then be immediately

immersed in water at room temperature. After the tiles have completely thawed in the water they
shall be removed, their surfaces wiped dry with a clean, damp cloth and a liquid dye rubbed upon
their surfaces. After being examined, the tiles shall again be immersed in water until such time as is
convenient to again place them in the freezing chamber for the additional cycles of the weather test.
After being subjected to 5 consecutive cycles of the foregoing weather test, the 5 samples tested
shall show no crazing, chipping, spalling, or cracking of either the body or glaze.

8. Glaze Hardness Test

A sample lot of tiles shall be used in the glaze hardness test utilizing Mohs Scale of Minerals. A piece
of mineral having a hardness of 4 as measured by Mohs Scale shall be slowly drawn across the
glazed surface of the tiles with a steady, uniform pressure approximately 11.3 kg. When subjected
to the above test, the glaze shall not show a scratch.

9. Flexural Strength

When tested according to EN 100 the flexural strength

shall be ≥ 27 PMa.

Standards and Codes for Tiling

Unless otherwise specified herein, installation procedures for ceramic tiles shall comply with the
current edition of the Tile Council of America (TCA) Installation Guide Handbook, ASTM Standards
listed herein, the American National Standards Institute (ANSI), as endorsed by the tile
Manufacturer, and as listed below:

•

ANSI A108.1B-1999

•

ANSI A108.5-1999

•

ANSI A108.10-1999

•

ANSI A108/A118/A136.1-2012

•

ANSI A137.1:2008

•

ASTM C150 / C150M - 12

•

ASTM C207 - 06(2011)

•

ASTM C778 - 12

•

ASTM C126 - 12

•

ASTM C499 - 09

•

ASTM C627

– 10

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-88

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Submittals for Tiling

The Contractor shall submit shop drawings to the Engineer showing, in detail the dimensions,
sections, jointing, anchoring devices, and tile setting numbers. No final sizing or finishing shall be
done until the shop drawings for that part of the work have been approved. Typical sections of the
wall shall be included on the shop drawings showing all configurations to be utilized on the walls.
Also full size details of perimeter terminations and details of joint conditions at concrete structural
wall expansion joints as well as at intermediate control joints in tile field between wall expansion
joints shall be shown.

The Contractor shall submit, for selection by the Engineer, samples of available stock tile colours in
the size and face finish specified, and available stock shades of tile grout compound and expansion
joint and control joint sealant proposed for use. After selection by the Engineer, the Contractor shall
prepare a site mock-up for review.

The Contractor shall submit for approval, as applicable, three samples for each of the following:

1.  Waterproofing and anti-fracture membrane
2.  Latex liquid, one-half litre with manufacturer's data
3.  Dry set mortar compound, one kilogram
4.  Dry set tile grout, one kilogram

Also, the Contractor shall submit the following:

A detailed method statement for tile fixing with specific Manufacturer’s recommendations.

2. Certified copies of results of tests performed on the facing tile as specified hereinafter.

Delivery, Storage, and Handling for Tiling

Where applicable, the Contractor shall deliver the materials in original unopened containers with
labels legible and intact, identifying brand name and contents. Manufactured mortars, additives, and
grouts shall bear hall-marks certifying compliance with specified standards. Materials shall be stored
under cover in a manner to prevent damage and to keep all material dry.

Site Conditions for Tiling

The Contractor shall adapt techniques approved by the Engineer to ensure that storage, handling,
and execution methods suit the environmental conditions that are encountered at the site and cause
no damage to the products or to the performance of the products in use. The Contractor shall follow
the recommendations of the product Manufacturers for storage of their products on site.
Environmental conditions shall include, but shall not be limited to, ambient temperature, humidity,
excessive sand/dust laden winds moisture in the air and on the products and surfaces with which
they are in contact, moisture content of the products and materials with which they are in contact,
and temperature of the product and the materials with which they are in contact.

Sealing for Tiling

The joints to be sealed shall be raked out free of mortar and grout compounds, dust and other foreign
material. The joints in contact with the sealant shall be primed or surface conditioned if
recommended by the sealant Manufacturer. A joint backer rod of proper diameter for the joint width
and to the depth recommended by the sealant Manufacturer shall be installed to provide the proper
sealant depth for the product used. Proper sealant as specified for the different joint widths shall be
applied, in a continuous operation, using positive pressure adequate to properly fill and seal the joint
against the backer rod and joint surfaces. The joints shall be lightly tooled to a smooth, slightly
concave surface. Surfaces adjacent to the sealant shall be protected by an approved means and
misplaced sealant removed from surfaces outside the recess provided for the sealant.

Cleaning for Tiling

Tiles  shall  be  cleaned  as  the  work  progresses,  and  tile  setting  and  grouting  material  shall  be
prevented  from  accumulating  on  the  tile  faces.  The  area  of  the  work  shall  be  kept  clean  and  all
cuttings,  droppings  and general  debris  shall  be  removed.  Upon  completion  and  curing  of  sealant

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-89

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

material, the tiles shall be washed down with a solution of detergent and water only, using soft fibre
brushes and clean cloths. No acids or metal tools of any kind shall be used. The tile surface shall be
rinsed with clean water and wiped dry with clean, soft cloths.

21.21.1.2 Textured Concrete Finish

Textured architectural concrete surfaces shall be as indicated on the Contract drawing, or as directed
by the Engineer, and shall be formed using proprietary architectural form liners.

21.21.1.3 Painting of Exposed Concrete

The surface preparation and painting of the exposed surfaces of the structures shall be as indicated
on the Contract drawings, as specified herein, and as directed by the Engineer.

Painting of exposed concrete shall comply with the requirements of Section 24.7 of Chapter 24,
Painting, of these Standard Specifications.

21.21.1.4 Fire Protection Boards

This section includes, but is not limited, to the supply and installation of fire boards to provide fire
protection to the tunnel/underpass ceiling and critical areas of the side walls, as shown on the
Contract plans, including fixing screws and anchors, and all accessories, to prevent the concrete
spalling in the event of a fire.

Tolerances

Fire protection boards shall be installed within 3 mm of the dimensioned height above the finish floor
level at any location, and shall be level within a maximum tolerance of 3 mm in 3 meters. Each
individual component shall have length and width tolerance of ± 1 mm in 2 meters and thickness
tolerance of ± 0.5 mm in 20 millimeters.

Quality Assurance

The installation of the fire boards shall be performed by a firm who has adequate equipment and
skilled mechanics to perform it expeditiously, and is known to have been responsible for satisfactory
installations similar to that specified during a period of at least five years.

Submittals

The Contractor shall submit shop drawings and material submittals showing, but not limited to,
details of all materials, boards layout, and the fixing screws and anchors layout with their type and
weight supported. A 600 mm x 600 mm sample of the fire board, and samples of screws and anchors,
shall be submitted to the Engineer for approval.

Materials

The following requirements are for the fire boards and their fixing system to the concrete. The fire
boards shall have a minimum two (2) hour fire rating as measured against the Rijkswaterstaat (RWS)
time-dependent curve. The temperature at the contact between the concrete and the fire board shall
not exceed 380

C and the temperature of the reinforcement within the structure shall not exceed

250

C. The thermal performance of the fire protection system shall be such that spalling of the

concrete is prevented. A fire test report of a certified test laboratory shall be submitted by the board
manufacturer. The test report shall describe fire test in which boards are tested on a similar concrete
surface. Extrapolations on the basis of other test reports are not permitted. The fire boards shall be
noncombustible in accordance with ASTM E136 - 12, and/or as defined in EN 13501, and shall meet
the requirements of NFPA 502 with a melting point of not less than 1350

C. It shall not produce toxic

smoke or fumes under fire exposure in accordance with ASTM E84 - 12b or equivalent international
standards. The complete fire protection system shall be designed to withstand a maximum wind
speed through the tunnel/underpass of 12m/s.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-90

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Site Conditions

The Contractor shall adapt techniques specified by the manufacturer and approved by the Engineer
to ensure that storage, handling, and execution methods suit environmental conditions that are
encountered at the site, and cause no damage to the products or to the performance of the products
in use. The Contractor shall follow the M

anufacturer’s recommendations for storage of their products

on site. Environmental conditions shall include, but shall not be limited to, ambient temperature,
humidity, moisture in the air and on the products and surfaces with which they are in contact, and
temperature of the products and the materials with which they are in contact.

Products

Where indicated on the Contract plans, the system shall consist of light weight boards complete with
all accessories, fixing screws and anchors, and other standard metal accessories of strength and
design compatible with Lost Formwork method and system specified by the Manufacturer. The board
thickness shall not exceed 270mm and shall be as recommended by the manufacturer to meet the
requirements of the relevant supporting fire test. All fixings used to secure the boards to the structure
shall be Stainless steel as follows. For boards fixed as “Lost Formwork” screws shall be stainless
steel

Grade 304 or A2 (1.4567). For boards “Post Fixed” anchors shall be stainless steel Grade 316

or A4 (1.4401). The complete fixing and anchoring system shall be such that, when used in practice,
will not fail or collapse during tunnel/underpass operation and during a fire. The fixing details shall
have an adequate level of redundancy to prevent any failure during its service life, as recommended
by the manufacturer and as approved by the Engineer.

Execution

Prior to installation of the fire protection system, the Contractor shall prepare a complete mock-up
(approximately 2.5m x 2.5m) for the Engineer’s approval. The Contractor shall coordinate the
installation of the fire boards specified in this article with that of other sections and articles. Adequate
preparation shall be made for attachment of fixing screw and anchors. Provision shall be made for
support and incorporation of flush-mounted and recessed service components. The fire protection
system shall be installed in accordance with the M

anufacturer’s recommendations and as approved

by the Engineer. Where boards are to be installed at the concreting stage they shall be anchored to
the concrete by means of 50mm screws set into the boards prior to concreting. Type of screws and
spacing of same, must be as recommended by the board Manufacturer and in compliance with the
relevant supporting fire test as approved by the Engineer. Where boards are to be fixed to the
finished concrete surface stainless steel anchors are to be used. Size, type and spacing of same to
be as per the board M

anufacturer’s recommendation and in accordance with the relevant supporting

fire test, as approved by the Engineer.

Extra Stock

The Contractor shall provide 2 percent of the quantity of each specified fire protection board, in each
finish, for extra stock. Extra stock shall be delivered in sealed labeled packages to a location as
directed by the Owner at completion of the maintenance period.

21.21.2

Miscellaneous Materials

Other miscellaneous materials used in conjunction with the surface finishing shall include, but not
be limited to the following.

1. Waterproofing and anti-fracture membrane shall be used in wet tiled areas and shall be thin,

cold applied, load bearing and non-toxic. The waterproof membrane shall be resistant to
urine, dilute acid, alkali, sugar, brine, and food waste products. Reinforcing fabric shall be
nonwoven rot-proof fabric specifically for use with waterproof membrane. All materials shall
be non-toxic, non-flammable, and non-hazardous during storage, mixing, application and
when cured. Waterproofing, crack suppression and anti-fracture membranes shall meet the
following requirements:

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-91

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Water Permeability

(at 91.2 kPa) Nil

Elongation at break

(ASTM D751 - 06(2011)) 40%

Service Temperatures

-28° to +137°C

Tensile breaking strength

20.4 MPa

Thickness

0.5mm

Bond strength to concrete

2.4MPa

Resistance to chemicals (90 day immersion):

Brine solution

not affected

Sugar solution

not affected

Milk

not affected

10% Acid

not affected

10% Alkali

not affected

Rubber solvents or ketones

not recommended

Calcium chloride

excellent

Aromatic solvents

not recommended

Floor tile installation evaluation

(ASTM C627 - 10) 900 cycles

Service Rating (TCA)

extra heavy duty

2. Cement shall be Portland Cement complying with ASTM C150 / C150M - 12, SRC Type V.
3. Aggregate shall be washed, sharp, natural sand complying with ASTM C144 - 11. Rounded

shape sand will not be acceptable.

4. The mortar bed shall be 15 mm thick (-2 and +5 mm) with styrene butadiene rubber (SBR)

emulsion additive, and meet the following requirements:

Sand 5.0 mm (max.)

Natural

As per BS EN 12620:2002+A1:2008

Cement

SRC Type V

ASTM C150 / C150M - 12

Compressive Strength (MPa)

28 days



27.0 (ASTM C109 / C109M - 11b)

Tensile Strength (MPa)

28 days



2.5 (ASTM C496 / C496M

– 11)

With at least 70.0% strength recovery in 7 days

5. Tile adhesive shall be cementitious with a thickness of 3.0 mm



1.0 mm, and meet the

following requirements:

Compressive Strength (MPa)

1 day



5.0

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-92

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Tensile Strength (MPa)

3 days



1.5

6. Tile grout shall be cementitious and have the following properties.

Compressive Strength (MPa)

1 day



4.0

Tensile Strength (MPa)

28 days



2.7

7. Joint sealant for application at 15 and 30 mm wide expansion joints shall be a

multicomponent, non-sag expoxidised polyurethane complying with ASTM C920 - 11, Type
II, Class A, 19-GP-24. Sealant for application at 10 mm wide control joints shall be single
component acrylic terpolymer complying with U.S. Federal Specification TT-S-230, non-sag,
19-GP-5b,  AAMA  808.3;  or  single  component  polyurethane  complying  with  U.S.  Federal
Specification TT-S-230, Type II, Class A; or single component silicone complying with U.S.
Federal Specification TT-S-1543, Class A or TT-S-230, Type II, Class A, 19-GP-9M. Colour
shall be dark brown or dark bronze as approved by the Engineer. The Contractor shall provide
joint  primer  or  conditioner  if  required  by  the  sealant  Manufacturer.  The  Contractor  shall
provide expanded, flexible and compressible closed cell polyethylene or butyl rubber backer
rod for all joints to be sealed. Backer rod shall be 12.7 mm in diameter for 10 mm wide joints,
19 mm in diameter for 15 mm wide joints and 38 mm in diameter for 30 mm wide joints.

Debonders shall be bituminous or tar based paint (two coats) as per the Manufacturer’s
recommendations and as approved by the Engineer.

9. Wire mesh reinforcement shall be galvanized welded steel wire fabric, 50mm by 50mm, 16

ga. (U.S. Std.).

10. Powder actuated fasteners shall be standard velocity, 31.75mm long by 3.57mm diameter

shank, tempered steel drive pins meeting the requirements of U.S. Federal Specifications
FF-P-395 and QQ-Z-325. The Contractor shall provide 38mm diameter galvanized sheet
steel washers for use with each drive pin in fastening wire reinforcement.

21.22

Scarifying Concrete Bridge Slabs

This work consists of scarifying concrete bridge slabs; removing and disposing of the cuttings
produced in accordance with these specifications; and conforming to the depths, profile grades, and
cross slopes at locations shown in the Contract documents.

21.22.1

Scarifying Equipment

Scarifying equipment provided by the Contractor shall be capable of the following:

•

Maintaining accurate depth of cut and slope;

•

Accurately establishing profile grades along each edge of the machine;

•

Automatically controlling cross slope at a given rate;

•

Uniformly varying the depth of cut while the machine is in motion; and,

•

Controlling dust created by the cutting action.

Unless otherwise permitted by the Engineer, the Contractor shall provide a machine equipped with
integral loading and reclaiming devices to immediately remove the cuttings from the surface of the
roadway and discharge them into a truck, all in a single operation.

Chipping tools shall be provided by the Contractor to remove concrete in small areas not accessible
to the mechanical scarifier.

21.22.2

Concrete Bridge Slab Construction

Existing concrete slabs shall be scarified to a uniform, rough surface having a chipped appearance
suitable for bonding a concrete overlay. Locations shown in the Contract plans, or as directed by the
Engineer, shall be scarified by the Contractor to the depths shown in the Contract plans. Depths

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-93

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

shall be measured by the Contractor from the level of the existing surface to the high points on the
scarified surface.

Appropriate care shall be taken by the Contractor to prevent damage to the bridge slab reinforcing
steel, armoured joints, slab joints, drainage hardware, and other appurtenances.

When appropriate, or required, the Contractor shall establish and maintain independent grade
control for concrete scarifying operations.

Chipping tools shall be used to remove concrete in small areas not accessible to the mechanical
scarifier.

Deck surfaces shall be immediately cleaned by the Contractor to remove all cuttings and debris,
which shall be disposed by the Contractor in locations outside the right-of-way (ROW).

21.23

Extending Concrete Structures

This work shall prepare and construct extensions and widenings of existing structures in accordance
with these specifications and conforming to requirements and details shown in the Contract
documents. Materials shall be furnished by the Contractor in accordance with the pertinent
requirements of the following:

•

Chapter 4, Concrete Works, of these Standard Specifications;

•

Chapter 5, Reinforcing Steel, of these Standard Specifications; and,

•

Chapter 21, Concrete Structures, of these Standard Specifications.

21.23.1

Concrete Structure Construction

Work shall be performed by the Contractor in accordance with Section 4.4 of Chapter 4, Concrete
Works, of these Standard Specifications; and the requirements of this chapter and this section.
Pertinent dimensions and elevations of existing structures shall be verified by the Contractor before
ordering any required materials.

21.23.1.1 Removal of the Existing Structure

Portions of the existing structure shall be removed by the Contractor to the lines and dimensions
shown in the Contract plans, or as directed by the Engineer. These materials shall be disposed of
by the Contractor as shown in the Contract plans, or as directed. Any metal railing shall be removed
without damaging it, and shall be stacked neatly along the ROW, at locations that do not interfere
with traffic or construction or at locations shown in the Contract plans. All removed metal railing
remains the property of the Owner, unless otherwise shown in the Contract plans. Any portion of the
remaining structure damaged as a result of construction shall be repaired by the Contractor.

Explosives shall not be used to remove portions of the existing structure, unless approved in writing
by the Owner. A demolition ball, other swinging weight, or impact equipment shall not be used by
the Contractor, unless show in the Concrete plans. Pneumatic or hydraulic tools shall be used for
final removal of concrete at the break line. Removal equipment shall be used as approved in a
manner not to cause any damage to the remaining concrete.

21.23.1.2 Reuse of Removed Portions of the Structure

All portions of the old structure that shall be incorporated into the extended structure shall be
detached and removed to the lines and details as specified in the Contract plans, or as directed by
the Engineer. Units to be reused shall be moved by the Contractor to new the new location specified
using approved methods. Reinforcement and extension concrete shall be placed according to the
Contract plan details.

21.23.1.3 Breaking Back Bridge Slabs

For bridge slabs and direct traffic slabs of box culverts, the Contractor shall saw the top surface of
the slab along the break line to a depth of 12.5 mm before breaking back. Reinforcements shall not

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-94

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

be cut at the break line and shall sever the concrete at the break line. During removal of the
designated portion of the existing structure, the Contractor shall not damage the remaining
reinforcement within 1 lap length of the break line.

21.23.1.4 Splicing Reinforcing Steel

New reinforcing bars shall be spliced by the Contractor to exposed bars in the existing structure
using lap splices in accordance with Section 5.5.4 of Chapter 5, Reinforcing Steel, of these Standard
Specifications

unless otherwise shown in the Contract plans. New reinforcing steel does not need

to be tied to the existing steel, where spacing or elevation does not match that of the existing steel,
provided that the lap length is attained. Welding shall be in accordance with Article 5.5.4.2 of Chapter
5, Reinforcing Steel, when welded splices are permitted. Any required dowels shall be installed by
the Contractor in accordance with Section 21.8 and Section 4.4.4 of Chapter 4, Concrete Works, of
these Standard Specifications

21.23.1.5 Concrete Preparation

Concrete surfaces that are in contact with new construction shall be roughened and cleaned by the
Contractor before placing of the forms. These construction joint surfaces shall be prepared in
accordance with this chapter. Roadway slabs shall be finished and cured in accordance with this
chapter.

21.24

Raising Existing Structures

This work consists of raising existing structures in accordance with these specifications and
conforming to requirements and details shown in the Contract plans. Materials shall be furnished in
accordance with the pertinent requirements of the following:

•

Chapter 4, Concrete Works, of these Standard Specifications;

•

Chapter 5, Reinforcing Steel, of these Standard Specifications; and,

•

Chapter 25, Bearing Devices, of these Standard Specifications.

21.24.1

Construction While Raising Existing Structures

Detailed plans to raise the structure shall be submitted by the Contractor. Approval of plans is
required before work may begin. A licensed professional engineer must sign and seal the plans and
the methods, materials, cribbing, falsework or other supports, and equipment proposed shall be
clearly indicated by the Contractor. Any portions of the structure damaged by the raising operation
shall be repaired or replaced by the Contractor. Approval of these plans by the Engineer does not
relieve the Contractor from responsibility for the completion of the work nor from liability for repair or
replacement of damaged portions of the structure due to the methods approved and employed.

21.24.1.1 Preparation of Plans

Loads shall be applied so that the load capacities in bearing, shear, and flexure are not exceeded
for any material or member carrying the load. Jack positions and capacities and temporary hardware
attachments shall be indicated on the plan. Jackings shall be avoided by the Contractor against the
bottom of the slab. A jack with a minimum capacity of two times the dead load shall be used. Traffic
on the structure shall be prohibited until the structure is supported by cribbing, falsework, or the final
supports.

Suitable cribbing, falsework, or other supports shall be provided by the Contractor until the span or
unit is resting on its final supports to prevent the various spans or units from dropping due to jack
failure or other causes during the lifting operation. Supports shall be designed to carry the greater of
the following loads:

•

Two times the dead load if traffic is not allowed on the structure; or,

•

One and one-quarter times the dead load plus 1.75 times the live load, including impact if the

plans allow traffic on the structure before it is placed on the final supports.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-95

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

21.24.1.2 Raising of Spans

Before jacking, the Contractor shall verify that anchor bolts, closed joints, or other appurtenances do
not  restrict  vertical  movement.  Spans  shall  be  jacked  from  the  existing  bent  cap  or  temporary
falsework, unless otherwise shown on the  Contract plans.  All anchor bolts shall be loosened and
removed  by  the  Contractor;  or  shall  cut  the  anchor  bolts  to  allow  free  vertical  movement  before
raising. All damaged or cut anchor bolts shall be replaced either by butt welding to existing bolts or
by drilling into the existing concrete cap a minimum of 300 mm and grouting in new bolts. Bent cap
reinforcing steel shall not be damaged when installing new anchor bolts. All damaged or lost anchor
bolt  nuts  shall  be  replaced.  Welding  shall  be  in  conformance  with  23.4.11  of  Chapter  23,  Steel
Structures.

Adequate guides or force shall be provided by the Contractor to ensure vertical lifting and prevent
drifting of the structure during the jacking operation. Pedestals shall be provided as shown in the
Contract plans.

Simple Spans with an Expansion Joint in the Deck at Every Bent

Spans shall be raised by jacking, as shown in the Contract plans. All of the beams shall be raised
on one side of the bent simultaneously. Raising one end of a simple span more than 100 mm before
raising the opposite end shall not be allowed.

Simple Beam Spans with a Continuous Deck over the Bent

All beams shall be raised on both sides of the bent simultaneously by jacking, according to the
Contract plans. Raising one end of a span more than 50 mm before raising the opposite end of the
span shall not be allowed.

Continuous Beams

Units shall be raised by jacking, according to the approved Contract plans. All beams shall be raised
at a single bent simultaneously. Units may be raised incrementally from bent to bent. Raising the
unit more than 50 mm at any bent before raising it at the adjacent bents shall not be allowed.

21.25

Spread Footings

This  work  shall  construct  reinforced-concrete  spread  footing  foundations  and  shall  include
dewatering,  when  necessary;  excavating to the required  limits;  compacting  the  underlying  soil  as
required;  and  constructing  seals,  when  required

—in accordance with these specifications and

conforming to requirements and details shown in the Contract documents. Materials shall be
furnished by the Contractor in accordance with the pertinent requirements of the following:

•

Chapter 4, Concrete Works, of these Standard Specifications;

•

Chapter 5, Reinforcing Steel, of these Standard Specifications; and,

•

Chapter 21, Concrete Structures, of these Standard Specifications.

21.25.1

General Requirements for Spread Footings

The Contractor shall meet the following requirements for all spread footings:

•

Perform excavations, including the removal of all material, of whatever nature, necessary for

the construction of spread footings. As used herein, the term soil shall constitute any material,
whether soil, rock, or other materials.

•

Slope excavations, as required, or support them with sheeting, and shore them to provide a

safe excavation that is adequate for construction purposes and that will adequately protect
any existing adjacent structures.

•

Ensure that the foundation soils are firm, stable, and, in the opinion of the Engineer, meet or

exceed the design bearing and compressibility requirements before constructing the footings
or any required seals. Owner may elect to use any type of tests to evaluate the foundation
soils that is appropriate in the opinion of the Engineer. When evaluating the foundation soils,

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-96

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

the Contractor shall cooperate and assist the Engineer, as necessary, to provide access to
the site.

•

Elevations of the bottom of footings or seals or the depth of over-excavation shown in the

Contract plans is approximate and the Engineer may order, in writing, such changes as may
be necessary to secure a satisfactory foundation.

•

Place all spread footing concrete in the dry.

21.25.2

Protection of Existing Structures

Existing  structures  shall  be  protected  in  accordance  with  Section  1.16.6  of  Chapter  1,  General
Requirements. Also, if not otherwise provided in the  Contract plans, the Contractor shall evaluate
the  need  for,  design,  and  provide  all  reasonable  precautionary  features  to  prevent  damage,
including, but not limited to, the installation of sheet piling, shoring as necessary, maintenance of the
water table beneath such structures as nearly as practical to existing conditions, and monitoring and
controlling vibrations from construction activities including driving of sheeting or from blasting.

21.25.3

Dewatering

Design, installation, and operation of an adequate dewatering system to dewater excavations for
spread footings is the responsibility of the Contractor, which shall use a well point or well system,
and submit a dewatering plan to the Engineer for its records before beginning construction.

Well points or wells shall be used by the Contractor where the piezometric water level is above an
elevation of 0.9 m below the bottom of the excavation. Water tables shall be maintained at 0.9 m or
more  below  the  maximum  depth  of  excavation.  Continuous  dewatering  shall  be  provided  until
completing  construction  of  the  footing  and  backfill  the  excavation  at  least  0.9  m  above  the
piezometric water table elevation. During dewatering operation, the shoring system shall be carefully
monitored  until  construction  is  completed  and  shoring  system  is  no  more  needed,  to  avoid  any
migration  of  soil from  behind  the  shoring system  to  avoid  any  caving  under  adjacent  locations  to
deter  the  collapse  of  soil  /  structures.  Dewatering  shall  continue  until  the  Engineer  considers
conditions safe to discontinue dewatering. If a dewatering failure occurs, the Contractor shall assist
the Engineer, as required in determining the effects of such a failure on the foundation soils, and
take whatever corrective measures are required at no additional expense to the Owner. When the
Engineer  approves  the  discontinuing  of  dewatering,  the  Contractor  shall  decrease  the  rate  of
pumping, allowing the water level to rise slowly. Rates measured in metres per hour shall be used
by the Contractor to ensure that the water table is allowed to rise equal to the total number of metres
the water table was lowered, divided by ten hours or a rate of 1 m/hr, whichever is less.

One piezometer well shall be installed by the Contractor approximately every 4.5 m of footing
perimeter. A minimum of two and a maximum of six piezometers shall be provided at locations within
0.6 m from the outside of the footing perimeter. Piezometer wells shall be installed by the Contractor
to a depth at least 3 m below the bottom of footing elevation, or as directed by the Engineer. Water
elevation shall be measured in the piezometer wells prior to excavation and at 12-hour intervals
between excavation and discontinuation of dewatering. Piezometers shall be maintained in working
condition throughout the dewatering process, and the Contractor shall repair or replace them when
damaged at no expense to the Owner.

21.25.4

Excavations

21.25.4.1 Dry Excavations

Dry excavations are excavations that can be completed without the need to lower the piezometric
water level. Dry excavations shall be performed by the Contractor when the piezometric water level
at the time of construction is and, in the opinion of the Engineer, will remain at least 0.9 m below the
bottom of the authorized excavation or over-excavation. It shall be demonstrated by the Contractor
to the Engineer that a stable excavation can be made without dewatering. Adequate provisions shall
be made to divert surface runoff and to collect and remove any water entering the excavation.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-97

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Excavation shall occur to the bottom of the footing, to the over-excavation limits shown in the
Contract plans, or as directed by the Engineer. Any suitable materials shall be saved for backfill.
Areas for the disposal of all unsuitable materials shall be provided by the Contractor, which shall
dispose of them in a satisfactory method. Foundation soils shall be compacted below the footing, as
shown in the Contract plans or described herein before constructing the footing.

21.25.4.2 Dewatered Excavations

Dewatered excavations are excavations made after first lowering the piezometric water level with
well points or wells. Dewatering shall be performed as described in Section 21.25.3, Dewatering.
Excavation shall occur in the dry after lowering of the water table.

When dewatering is required, the Contractor may excavate within 0.9 m of the ground water table
before dewatering begins

— if the dewatering system is operating and the Contractor has

demonstrated that the water level has been lowered to and maintained at acceptable limits. Where
large excavations require stage lowering of the water table, and where additional well point systems
are installed at lower elevations, the Contractor may continue excavating as long as the water
elevation is maintained at least 0.9 m below the excavation.

Surface runoff shall be diverted from the excavation. Foundation soils shall be compacted as shown
in the Contract plans or as described herein before constructing the footing.

21.25.4.3 Wet Excavations

Wet excavations are excavations made below the existing water table, without prior dewatering.
When the Contract plans show a cofferdam and seal, the Contractor shall perform the excavation in
the wet. Water levels shall be maintained during excavation at or above the water level outside the
cofferdam.

Seals shall be placed by the Contractor directly upon the foundation soils or rock when using wet
excavations. Foundation soils shall not be compacted for wet excavations. Foundation soils or rocks
shall be disturbed by the Contractor as little as practical. All materials that are determined by the
Engineer to be loose or disturbed before placing the seal concrete shall be removed.

21.25.5

Fill or Backfill

The Contractor shall only use fill or backfill, including over-excavations below the footing that is clean
cohesionless material, free of rubble, debris, or rocks that would prevent uniform placement and
compaction. For backfill materials, the Contractor shall use A-1, A-2, or A-3 materials conforming to
AASHTO M 145-91 (2008), materials as shown in the Contract plans, or materials approved by the
Engineer.

21.25.6

Compaction and Density Requirements

Excavation bottoms shall be compacted by the Contractor with suitable equipment. Soils beneath
footing excavation shall be compacted

— whether dug to the bottom of footing or over-excavated —

to a density not less than 95 percent of the maximum density, as determined by AASHTO T180, for
a minimum depth of 60 mm below the bottom of the excavation or to the depth shown in the Contract
plans before backfilling begins. At least one density determination shall be performed by the
Contractor at each footing excavation at a depth of 0.3 m to 0.6 m below the bottom of the excavation.
Backfill shall be compacted by the Contractor in footing excavations that have been over-excavated
in 0.3-m maximum loose lifts to a density not less than 95 percent of the maximum density

— as

determined by AASHTO T180 to the bottom of footing elevation. At least one density determination
shall be performed in each lift of backfill at each footing excavation.

For compaction, the Contractor shall use an approved heavy vibratory roller with a static drum weight
of at least 4 tons. Each lift shall be compacted to the required density. Also, the Contractor shall
compact the final lift below the footing with a suitable sled vibratory compactor to remove any upper
disturbance caused by the drum roller. When conditions require use of smaller compaction

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-98

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

equipment, the Contract

or shall obtain the Engineer’s approval for the equipment, and reduce the lift

thickness to achieve the required density.

Backfilling shall be performed by the Contractor to the original ground surface, finished grade, or
subgrade

— as required by the Contract plans in the immediate vicinity by approved mechanical

compactors weighing less than 450 kg. Backfill located more than 4.5 m away from the exterior
periphery of the footings may be compacted by the Contractor with heavier compactors. Backfill shall
not be placed on the footings until the Engineer has given permission and until the concrete is at
least seven days old.

21.25.7

Forming

Spread footings shall be formed by the Contractor if it cannot be demonstrated that the natural soil
or rock is strong enough to prevent caving during construction. For forms, the applicable
requirements of Section 1.20 of Chapter 1, General Requirements, shall be met. When forms are
not required, where footing concrete can be placed in dry excavation, the Contractor may omit cribs,
cofferdams, and forms, subject to compliance with the following limitations and conditions:

•

Use this procedure only in locations not exposed to view from travelled roadways.

•

Obtain required elevations shown in the Contract plans.

•

Obtain neat line dimensions shown in the plans.

•

Fill the entire excavation with concrete to the required elevation of the top of the footing.

•

The Engineer will determine the volume of footing concrete to be paid for from the neat line

dimensions shown in the Contract plans.

21.25.8

Reinforcing Steel Placement

Reinforcing steel for footings shall be placed and fastened by the Contractor according to the
applicable provisions of Section 5.5.2 of Chapter 5, Reinforcing Steel, of these Standard
Specifications.

21.25.9

Concrete Placement

21.25.9.1 Placement

All footing concrete shall be placed by the Contractor in the dry and according to the applicable
provisions of this chapter. Joints shall not be constructed in the footings.

21.25.9.2 Finish

After placing and consolidating the concrete, the Contractor shall strike-off the top surface to the
grades shown in the Contract documents, leaving the surface smooth and free of undesirable
cavities and other defects. A special finish shall not be provided by the Contractor unless the footing
will be visible after construction, in which case, the applicable provisions of this chapter shall be met.

21.25.9.3 Curing

Continuous-moisture-curing for footings shall be provided by the Contractor. For cover materials, the
Contractor shall use clean sand, sawdust, or other materials meeting the approval of the Engineer.
Continuously the cover materials shall be wetted for a period of 72 hours.

21.26

Steps

Steps, ramps, or other grade adjustment-type concrete works shall be constructed where final
sidewalk grades are too low or too high to match existing plot entries, building floor levels or other
existing paving or sidewalk areas. When required, each site shall be designed site-specific by the
Contractor, and shown in the plans and sections in the shop drawings for approval by the Engineer.
This section covers any concrete work required to match paved pedestrian areas to existing

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-99

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

pedestrian areas or other features that require some type of concrete grade adjustment structure
such as steps, ramps, barriers or low retaining walls.

Although each site is to be designed site-specific, steps shall be maintained as close as possible to
the ideal dimensions of 30-cm tread width to 15-cm rise, with the tread sloping down 12.5 percent
from inner to outer edges, and the riser sloping inwards 14.3 percent from top to bottom. Step edges
shall also be rounded 1.5 cm and provided with a nonslip surface by lightly brooming the finished
tread surface lengthwise, all as approved by the Engineer. Steps, ramps, and other concrete grade
adjustment works shall be reinforced with minimum shrinkage and cracking reinforcement, or to the
reinforcement percentage required for structural load bearing capacity as per American Concrete
Institute (ACI) codes, as required and approved by the Engineer.

21.26.1

Materials for Steps

All reinforcing steel and concrete shall comply with the requirements under Chapter 5, Reinforcing
Steel, of these Standard Specifications; and this chapter. The class of concrete shall be C35/20.
Reinforcement shall be Grade 60 rebar or welded wire mesh complying with Section 5.3 of Chapter
5, Reinforcing Steel, of these standard specifications. Concrete surface sealants shall meet the
requirements of Section 29.6 of Chapter 29, Miscellaneous Items for Structures, of these standard
specifications.

21.26.2

Steps Construction

All steps, ramps, and other concrete works under this section shall be cast-in-situ. Forms shall be
smooth and tight-fitting, which can be held rigidly to line and grade during placing of concrete, and
which can be readily removed without injuring the green concrete. All form detail work shall comply
with the requirement as specified in Section 1.20 of Chapter 1, General Requirements.

Expansion and contraction joints shall be placed in all concrete sections larger than 3 m in any one
direction, and between existing concrete works and the new concrete. Where steps and ramps abut
existing concrete grade structures, the new concrete shall be tied to the existing concrete by shear
dowels drilled and epoxied into the existing concrete face, which shall be used where the possibility
of excessive load transfers may exist or where the foundation for the steps or ramps is of marginal
support capability.

Tread surfaces of steps and ramps shall be finished with at least two passes of a trowel to a smooth,
even finish, then roughed up for a nonslip surface by lightly brooming 90 degrees to the travel axis
of the ramp or steps with a wet straw broom. Step riser faces, sidewalls, and fronts of barriers and
retaining walls shall receive a Class 2, Rubbed Finish. In some instances, the steps or ramp treads
may be faced with Quarry Tiles, in which case the tread shall be finished to a level surface with the
Quarry Tiles grouted into place

— as per the requirements of Article 7.6.2.1 of Chapter 7, Incidental

construction, of these Standard Specifications. Exposed surfaces of all steps, ramps, and other
concrete grade adjustment structures shall be protected by a clear penetrate sealer

— as per the

requirements of Section 29.6 of Chapter 29, Miscellaneous Items for Structures, of these standard
specifications.

21.27

Concrete for Minor Structures

This work shall construct minor concrete structures, such as pipe culvert headwalls, wing-walls and
aprons, spillways, slope paving, sidewalks, curbs, and other minor concrete structures in accordance
with these specifications and in reasonable close conformity with the lines, grades, details and
locations shown on the Contract plans or established by the Engineer.

21.27.1

Materials for Minor Structures

All minor concrete structure materials shall conform to the requirements contained in Chapter 4,
Concrete Works, of these Standard Specifications

;

and this chapter.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-100

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

21.27.2

Composition of Concrete for Minor Structures

Concrete for minor structures shall conform to the requirements of Chapter 4, Concrete Works, of
these Standard Specifications

;

and this chapter. Before batching concrete, the Contractor shall

submit the proposed concrete proportions for approval. As a minimum, the following shall be
submitted:

•

Type and sources of all material proposed for use.

•

Material certification for all material proposed for use including cement.

•

Saturated surface dry weight of the fine and coarse aggregate per cubic metre of concrete.

•

Gradation of fine and coarse aggregate.

•

Weight of mixing water per cubic metre of concrete.

•

Weight of cement per cubic metre of concrete.

For structural applications, Class C35/20 concrete complying with Chapter 4, Concrete Works, of
these Standard Specifications

will be acceptable as an approved mixture with appropriate

certification.

Preparatory work shall be performed by the Contractor in accordance with the applicable
requirements of Chapter 1, General Requirements, and Chapter 2, Earthworks, of these Standard
Specifications, for the structure excavation and backfill. Forms shall be designed and constructed by
the Contractor in accordance with Section 1.20.8 of Chapter 1, General Requirements. Forms shall
be free of bulge and warp and allow for removal without injuring the concrete. Reinforcing steel shall
be placed in accordance of Chapter 5, Reinforcing Steel, of these Standard Specifications. When
concrete contains a retarding admixture, fly ash, or other pozzolan replacement for cement, forms
shall be designed for a lateral pressure equal to that exerted by a fluid having a mass of 2,400 kg/m3.
Wood, metal, or other suitable material shall be used. Forms shall be kept clean and coated with
form release agent or form oil before placing concrete.

21.27.3

Placing of Concrete

Forms and foundations shall be moistened immediately before placing concrete. Concrete shall be
discharged within the proper time limit specified in Chapter 4, Concrete Works, of these Standard
Specifications

Concrete shall be handled and placed to avoid segregation in accordance with Section 21.7,
Handling and Placing Concrete. Aluminium pipe for transporting or placing concrete shall not be
used. Intervals between batch deliveries for a single pour on a structure shall not exceed 20 minutes,
unless suitable concrete admixtures are used. The formation of cold joints shall be strictly avoided.

Placement of concrete shall conform to the requirements of Section 21.6, Protection of Concrete,
when there is a forecast of air temperatures above 32 degrees Celsius.

Water shall not be supplied to plastic concrete finishes during finishing operations.

21.27.4

Curing of Concrete

Minor concrete shall be cured a minimum of seven days. Curing shall be according to Section 21.11,
Curing Concrete.

21.27.5

Acceptance

Concrete for minor structures will be subject to acceptance or rejection by visual inspection and
review of the load certification at the placement site. Re-tempering of concrete shall not be permitted.
Quality control shall be as per Chapter 4, Concrete Works, of these standard specifications.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-101

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

NDEX

abutments, 21-46, 21-73
Accessories, 21-11
additional testing, 21-10
anchorages, 21-50, 21-55, 21-67, 21-70, 21-

anodic, 21-16
Approach slabs, 21-27
Arch ring, 21-23
architectural rustication, 21-46
armour, 21-32, 21-33, 21-35
autoclave, 21-86
backfill, 21-75, 21-96, 21-97, 21-100
base slab, 21-24, 21-33, 21-36, 21-73
beams, 21-20, 21-23, 21-27, 21-49, 21-50, 21-

55, 21-62, 21-95

Bituminous protective coating, 21-67
Blinding concrete, 21-27, 21-28
bonding agents, 21-11, 21-55, 21-56, 21-57,

21-58, 21-59

bridge decks, 21-1, 21-20, 21-21, 21-37, 21-

38, 21-39, 21-41, 21-42, 21-44, 21-71, 21-
75

bridges, 21-1, 21-9, 21-12, 21-23, 21-37, 21-

38, 21-40, 21-44, 21-76, 21-77, 21-84

brooming, 21-40, 21-41, 21-49, 21-99
burlap, 21-40, 21-42, 21-45
camber, 21-27, 21-38, 21-40, 21-49, 21-54,

21-61, 21-63, 21-64, 21-65, 21-66, 21-68,
21-76, 21-78

cathodic, 21-16
Cementitious materials, 21-9, 21-10
Ceramic, 21-2, 21-7, 21-85
Certificates, 21-67
chairs, 21-11, 21-60
chemical admixtures, 21-9
Coarse aggregate, 21-10
coated reinforcement, 21-11
columns, 21-22, 21-50
compaction, 21-29, 21-60, 21-61, 21-69, 21-

Concrete classes, 21-9
concrete placement plan, 21-22
Concrete sequence placement, 21-23
concrete surface, 21-20, 21-26, 21-36, 21-38,

21-39, 21-41, 21-43, 21-44, 21-49, 21-59,
21-68, 21-73, 21-79, 21-89, 21-90

construction joints, 21-22, 21-23, 21-31, 21-

32, 21-36, 21-37, 21-42, 21-81

contraction joints, 21-32, 21-33, 21-34, 21-39,

21-99

copper, 21-35
core temperature, 21-28, 21-29

couplers, 21-67, 21-79, 21-82
crack controlling additive, 21-28
cracks, 21-22, 21-24, 21-39, 21-61, 21-66, 21-

71, 21-73, 21-84, 21-86

culverts, 21-1, 21-9, 21-12, 21-24, 21-93
dead-load deflection, 21-66
deck girder spans, 21-23
deck panels, 21-27, 21-50, 21-51, 21-54, 21-

55, 21-63, 21-66

defects, 21-33, 21-45, 21-61, 21-66, 21-74,

21-86, 21-98

Design calculations, 21-78
Dewatered excavations, 21-97
dimensional tolerances, 21-51, 21-61, 21-62,

21-63, 21-64, 21-65

Dry excavations, 21-96
ducts, 21-59, 21-66, 21-67, 21-68, 21-69, 21-

74, 21-77, 21-78, 21-79, 21-83

embedded items, 21-11, 21-48, 21-69, 21-77
enclosures, 21-20
environmental conditions, 21-20, 21-88, 21-90
epoxy-coated, 21-11, 21-25
equipment loads, 21-75
existing concrete, 21-32, 21-95, 21-99
Existing slabs, 21-27
existing structures, 21-93, 21-94
expansions joints, 21-37
exposed slabs, 21-20
falsework, 21-19, 21-23, 21-38, 21-39, 21-66,

21-68, 21-71, 21-78, 21-94, 21-95

Falsework, 21-1, 21-68
fascia elements, 21-55
fascia members, 21-10
filled joints, 21-32, 21-35
fine aggregate, 21-9, 21-18, 21-72
fire protection, 21-89, 21-90
flexural strength, 21-33, 21-36, 21-57, 21-74,

21-87

fog sprayers, 21-21
footings, 21-22, 21-24, 21-73, 21-95, 21-96,

21-98

frequency, 21-10, 21-17
galvanic corrosion, 21-11
gel time, 21-56, 21-59
geometric control, 21-76
girders, 21-23, 21-44, 21-49, 21-52, 21-53, 21-

54, 21-55, 21-60, 21-63, 21-68, 21-69, 21-
71, 21-76

grout, 21-9, 21-10, 21-25, 21-32, 21-35, 21-37,

21-45, 21-50, 21-51, 21-54, 21-55, 21-67,
21-70, 21-71, 21-73, 21-74, 21-75, 21-78,
21-79, 21-88, 21-92

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-102

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

grouting, 21-66, 21-67, 21-70, 21-71, 21-75,

21-79, 21-81, 21-88, 21-95

Grouting, 21-70
hardboard, 21-33, 21-36, 21-74
high performance, 21-28
high temperatures, 21-21, 21-43
high-performance concrete, 21-41
high-strength, 21-11
hold-down devices, 21-11
honeycombed areas, 21-66
horizontal joints, 21-31
hot-dipped galvanized, 21-11
immersion-type vibrators, 21-25
inaccessible, 21-39
incremental launching, 21-84
independent laboratory, 21-10, 21-56, 21-75
injection, 21-37, 21-70, 21-84
keys, 21-24, 21-31
Laboratory tests, 21-12
Launching forces, 21-84
lifting devices, 21-11, 21-52, 21-79, 21-83
Lifting devices, 21-52
Liquid concrete admixture, 21-16
low humidity, 21-21
low-alloy carbon steel, 21-11
low-density, 21-9, 21-12
masonry plates, 21-41, 21-74
Mass concrete, 21-28
match-cast segments, 21-56, 21-76, 21-80,

21-83

mineral admixtures, 21-9, 21-15, 21-44
minor concrete structures, 21-99
miscellaneous, 21-1, 21-9, 21-12, 21-81, 21-

mix designs, 21-10, 21-14
mortar, 21-9, 21-10, 21-22, 21-24, 21-25, 21-

35, 21-36, 21-39, 21-40, 21-41, 21-45, 21-
46, 21-49, 21-54, 21-55, 21-66, 21-70, 21-
71, 21-74, 21-75, 21-79, 21-88, 21-91

mortar-tight, 21-49, 21-54, 21-71, 21-75
natural sand, 21-9, 21-10, 21-91
non-shrink, 21-10, 21-51, 21-74
Open time, 21-56, 21-57
pedestrian, 21-41, 21-98
permanent, 21-27, 21-77, 21-79, 21-80, 21-

81, 21-82, 21-87

pier shafts, 21-2
piers, 21-44, 21-46, 21-73, 21-82, 21-84
pigments, 21-43, 21-55
pipe sleeves, 21-11
plant batches, 21-12
Post-tensioned, 21-66, 21-67
Pre-moulded, 21-32
prestressed members, 21-10, 21-44, 21-49,

21-61

prestressing forces, 21-19

protection, 21-16, 21-19, 21-20, 21-21, 21-22,

21-36, 21-44, 21-55, 21-77, 21-83, 21-85,
21-89, 21-90

pumps, 21-25, 21-26
railing, 21-2, 21-93
ramps, 21-98, 21-99
reinforced-concrete bridge slabs, 21-26
Re-injectable, 21-36
retaining walls, 21-46, 21-73, 21-99
risks, 21-29
Rock surfaces, 21-24
sag, 21-27, 21-56, 21-92
salt water, 21-21, 21-22
Sampling, 21-2, 21-4, 21-16, 21-17, 21-51, 21-

scarifying, 21-92, 21-93
Screed concrete, 21-28
sealants, 21-32, 21-33, 21-35, 21-99
segmental construction, 21-76, 21-79, 21-80
settlement, 21-16, 21-23, 21-24, 21-38, 21-39,

21-82

shoring, 21-68, 21-96
Shrinkage, 21-10, 21-18
sidewalks, 21-35, 21-41, 21-99
skid-resistant surface, 21-37
slip form, 21-2
smoothness, 21-39, 21-40, 21-61, 21-64, 21-

65, 21-66, 21-72

solvent, 21-55
Spacers, 21-11
spread footing, 21-95, 21-96
stainless steel, 21-11, 21-36, 21-90
stainless-steel, 21-11, 21-51
standard deviation, 21-13
standard test cubes, 21-14
Stay-in-place (SIP) form, 21-66
steel shapes, 21-11, 21-71
Steel shims, 21-51
Steps, 21-98, 21-99
straightedge, 21-39, 21-40, 21-41, 21-61, 21-

strands, 21-19, 21-50, 21-51, 21-60, 21-61,

21-62, 21-65, 21-66, 21-67, 21-70

Stressing operations, 21-69
Stuttgart, 21-16
substructure, 21-22, 21-23, 21-73, 21-76
sulphate soils, 21-22
sulphate water, 21-22
superstructure, 21-23, 21-67, 21-69, 21-71,

21-73, 21-76, 21-77, 21-78, 21-79, 21-80,
21-81, 21-82

supports, 21-11, 21-38, 21-49, 21-52, 21-60,

21-78, 21-80, 21-94

surface mortar, 21-20
surface treatment, 21-85
T-beam, 21-23

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 21-103

HAPTER

21:

ONCRETE

TRUCTURES

First Edition -January 2018

Temperature deflection tests, 21-58
test specimens, 21-9, 21-10, 21-26, 21-57, 21-

58, 21-60

testing, 21-9, 21-10, 21-16, 21-17, 21-19, 21-

27, 21-40, 21-48, 21-51, 21-56, 21-57, 21-
58, 21-60, 21-71, 21-86

texture, 21-12, 21-40, 21-41, 21-45, 21-46, 21-

49, 21-54, 21-55, 21-72, 21-73, 21-74, 21-
75

thermal control, 21-28, 21-29
threaded inserts, 21-51
ties, 21-11, 21-45, 21-49, 21-50
time-dependent, 21-76, 21-89
trial batches, 21-12
tunnels, 21-1
underpasses, 21-1
underwater, 21-25, 21-26

variations, 21-13, 21-14, 21-41
Vehicles, 21-75
vertical joints, 21-31
Vibrators, 21-25
Water absorption, 21-10, 21-18
waterproof, 21-19, 21-35, 21-36, 21-42, 21-43,

21-51, 21-74, 21-90

water-reducing admixtures, 21-15
Waterstops, 21-32, 21-33, 21-34, 21-35, 21-

water-tightness, 21-1
Welding electrodes, 21-12
Wet excavations, 21-97
windbreaks, 21-20
wingwalls, 21-46, 21-73
wires, 21-70, 21-84
Workability, 21-12

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page i

HAPTER

22:

RESTRESSING

YSTEMS

First Edition -January 2018

Chapter 22: Prestressing Systems

ABLE OF

ONTENTS

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

List of Figures ................................................................................................................................. iii

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

Prestressing Systems ...................................................................................................... 22-1

22.1

Prestressing Definitions ............................................................................................... 22-1

22.2

Details of Prestressing Design ..................................................................................... 22-1

22.3

Reference Standards and Codes ................................................................................. 22-2

22.4

Prestressing Quality Assurance ................................................................................... 22-5

22.4.1

Qualifications of Prestressing Subcontractor ......................................................... 22-5

22.4.1.1

Precast Prestressed Girder ............................................................................ 22-6

22.4.1.2

Post-tensioned Concrete ............................................................................... 22-6

22.4.1.3

Supervision of Prestressing Operations ......................................................... 22-6

22.5

Supplementary Drawings ............................................................................................. 22-7

22.5.1

Working Drawings ................................................................................................. 22-7

22.5.2

Shop Drawings ..................................................................................................... 22-7

22.5.3

Composite Placement Drawings ........................................................................... 22-8

22.6

Submittals .................................................................................................................... 22-8

22.6.1

Qualification Details .............................................................................................. 22-9

22.6.2

Working Drawings ................................................................................................. 22-9

22.6.3

Certificates ............................................................................................................ 22-9

22.6.4

Test Reports ......................................................................................................... 22-9

22.7

Materials for Prestressing Operations .......................................................................... 22-9

22.7.1

Prestressing System Materials .............................................................................. 22-9

22.7.1.1

Post-tensioning Systems ............................................................................... 22-9

22.7.1.2

Prestressing Steel and Anchorage ............................................................... 22-10

22.7.1.3

Post-tensioning Anchorage and Couplers .................................................... 22-11

22.7.2

Grout .................................................................................................................. 22-14

22.7.2.1

Approval ...................................................................................................... 22-14

22.7.2.2

Mixing .......................................................................................................... 22-14

22.7.2.3

Grout Physical Properties ............................................................................ 22-15

22.7.3

Ducts for Prestressing Operations ...................................................................... 22-17

22.7.3.1

Metal Ducts for Prestressing ........................................................................ 22-18

22.7.3.2

Plastic Ducts for Prestressing ...................................................................... 22-18

22.7.3.3

Duct Area .................................................................................................... 22-19

22.7.3.4

Duct Fittings ................................................................................................. 22-19

22.8

General Prestressing Requirements .......................................................................... 22-19

22.8.1

Concrete Strength ............................................................................................... 22-20

22.8.2

Prestressing Equipment ...................................................................................... 22-20

22.8.2.1

Cutting ......................................................................................................... 22-20

22.8.2.2

Sequence of Stressing ................................................................................. 22-21

22.8.2.3

Measurement of Stress ................................................................................ 22-21

22.8.3

Pretensioned Members ....................................................................................... 22-21

22.8.3.1

Pre-tensioning Requirements....................................................................... 22-21

22.8.3.2

Placement of Prestressing Steel .................................................................. 22-23

22.8.3.3

Releasing of Prestressing Steel ................................................................... 22-24

22.8.4

Post-tensioned Members .................................................................................... 22-24

22.8.4.1

Post-tensioning Requirements ..................................................................... 22-24

22.8.4.2

Placement of Ducts ...................................................................................... 22-24

22.8.4.3

Placement of Concrete ................................................................................ 22-26

22.8.4.4

Placement of Post-tensioning Steel ............................................................. 22-27

22.8.4.5

Placement of Anchorage .............................................................................. 22-28

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 22-1

HAPTER

22:

RESTRESSING

YSTEMS

First Edition -January 2018

PRESTRESSING SYSTEMS

This chapter outlines requirements with which the Contractor shall comply when prestressing precast
or cast-in-place concrete by furnishing, placing, and tensioning prestressing steel. Such work shall
also comply with the particular specifications and details. This chapter applies to prestressing by
either the pre-tensioning method, the post-tensioning method, or a combination of these methods.

Work for which the specifications in this chapter apply includes furnishing and installing items that
are necessary to complete the prestressing system as part of the construction of the Project. Such
items may include, but are not limited to, ducts, anchorage assemblies, grout used for pressure
grouting ducts, and gauges and testing equipment for assessing various prestressing parameters.

When a structural member, such as a beam, girder, slab, or column, contains both pre-tensioned
steel and post-tensioned steel, both methods shall comply with the applicable requirements of this
chapter’s specifications.

This chapter of the standard specifications also include requirements for the supply, fabrication,
delivery, testing, installation, stressing, and permanent corrosion protection of structural cable
members such as hanger cables and transverse tie cables.

22.1

Prestressing Definitions

Pretensioned prestressed concrete is concrete in which prestressing strands or wire are tensioned
before placing the concrete and released after the concrete has gained sufficient strength to retain
the prestressing force by bond.

Post-tensioned prestressed concrete refers to concrete in which the stressing steel is placed in voids
or ducts installed within the concrete member, and is stressed and anchored after the concrete has
developed a specified strength. As a final operation, the voids or ducts are filled with grout under
pressure. For cast-in-place prestressed concrete, the term member, as used in this chapter, shall
mean the concrete that is to be prestressed.

22.2

Details of Prestressing Design

When the Contract plans do not fully detail the design for the prestressing work, the Contractor shall
furnish the details or type of prestressing system for use and select materials and details that conform
to these specifications, as needed, to satisfy the specified prestressing requirements. Each selected
system shall provide the magnitude and distribution of prestressing force and ultimate strength
required by the Contract plans without exceeding allowable temporary stresses. Unless otherwise
shown in the Contract plans, all design procedures, coefficients and allowable stresses, friction, and
prestress losses

— as well as tendon spacing and clearances — shall be in accordance with the

American Association of State Highway and Transportation Officials (AASHTO) Load and
Resistance Factor Design (LRFD) Bridge Design Specifications, the AASHTO Guide Specifications
for Design and Construction of Segmental Concrete Bridges, and the Road Structures Design
Manual (ADQCC TR-516) as applicable.

Prestressing may be performed by either the pre- or post-tensioning methods. If the Contract plans
show only pre-tensioning details, the use of a post-tensioning system will be allowed only if the
Engineer approves the complete details of any necessary modifications.

When the effective or working force

— or stress — is shown in the Contract plans, it shall be

considered to be the force or stress remaining in the prestressing steel after all losses, including
creep and shrinkage of concrete, elastic shortening of concrete, relaxation of steel, friction and take
up or seating of anchorages, and all other losses particular to the method or system of prestressing
have taken place or have been accounted for. When the jacking force is shown in the Contract plans,
it shall be considered to be the force applied to the tendon prior to anchorage and the occurrence of
any losses, including the anchor set loss.

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 22-2

HAPTER

22:

RESTRESSING

YSTEMS

First Edition -January 2018

22.3

Reference Standards and Codes

Standards and codes 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

Guide Specifications for Design and Construction of Segmental Concrete
Bridges;

AASHTO

Standard Specifications for Transportation Materials and Methods of
Sampling and Testing;

ACI

American Concrete Institute;

ACI 503 (1997)

Standard Specification for Bonding Hardened Concrete, Steel, Wood, Brick,
and Other Materials to Hardened Concrete with a Multi-Component Epoxy
Adhesive;

ADQCC (TR-516)

Road Structures Design Manual;

ASTM

American Society for Testing and Materials;

British Standards;

BS EN

European Standards;

CCRL

Cement and Concrete Reference Laboratory;

CEB-FIP Model

Code1990;

FDOT

New Direction for Florida Post-Tensioned Bridges, Florida Department of
Transportation;

Federal Specification MIL-P-3420F-87;

ISO

International Organization for Standardization;

PCI

Precast/Prestressed Concrete Institute;

PCI MNL-116-99

Manual for Quality Control for plants and production of Structural Precast

Concrete Products;

PCI MNL-117-77

Manual for Quality Control for Plants and Production of Architectural Precast
Concrete Products (1977);

PTI

Post-Tensioning Institute - Guide Specification for Grouting of Post-Tension
Structures, Post-Tensioning Institute;

PTI

Post-Tensioning Institute - Recommendations for Stay Cable Design, Testing,
and Installation;

U.S. Army

Corps of Engineers Method CRD C79;

U.S. Military

Specification and Standards MIL-P-24441/20.Table 22-1 and

TANDARD

ONSTRUCTION SPECIFICATIONS

PART

–

OAD

TRUCTURES

Page 22-3

HAPTER

22:

RESTRESSING

YSTEMS

First Edition -January 2018

Table 22-2 presents American Association of State Highway and Transportation Officials (AASHTO),
American Society for Testing and Materials (ASTM), British (BS), and European (BS EN) Standards
that are related to materials for prestressing steel works. It also includes designations and titles.

Table 22-1: Designations and titles for AASHTO and ASTM standards that apply to

prestressing steel works

AASHTO
Designation

ASTM
Designation

Title

AASHTO M
275M/M 275-08

ASTM A722/
A722M - 12

Standard Specification for Uncoated, High-Strength
Steel Bars for Prestressing Concrete

AASHTO M
204M/M 204-06
(2010)

ASTM A421/
A421M - 10

Standard Specification for Uncoated, Stress-Relieved
Steel Wire for Prestressed Concrete

AASHTO M
203M/M 203-12

ASTM A 416/
A416M - 12

Standard Specification for Steel Strand, Uncoated
Seven-Wire for Prestressed Concrete

ASTM C1152/
C1152M - 04e1

Standard Test Method for Acid-Soluble Chloride in
Mortar and Concrete

ASTM C33 /
C33M - 11a

Standard Specification for Concrete Aggregates

ASTM C1090 -
10

Standard Test Method for Measuring Changes in
Height of Cylindrical Specimens of Hydraulic-Cement
Grout

ASTM C942 - 10

Standard Test Method for Compressive Strength of
Grouts for Preplaced-Aggregate Concrete in the
Laboratory

ASTM C953 - 10

Standard Test Method for Time of Setting of Grouts for
Preplaced-Aggregate Concrete in the Laboratory

ASTM C939 - 10

Standard Test Method for Flow of Grout for Preplaced-
Aggregate Concrete (Flow Cone Method)

ASTM C940

–

10a

Standard Test Method for Expansion and Bleeding of
Freshly Mixed Grouts for Preplaced-Aggregate
Concrete in the Laboratory

AASHTO T 277-
07 (2011)

ASTM C1202 -
12

Standard Test Method for Electrical Indication of
Concrete's Ability to Resist Chloride Ion Penetration

ASTM D3895 -
07

Standard Test Method for Oxidative-Induction Time of
Polyolefins by Differential Scanning Calorimetry

ASTM D4101 -
11

Standard Specification for Polypropylene Injection and
Extrusion Materials

ASTM D3350 -
12

Standard Specification for Polyethylene Plastics Pipe
and Fittings Materials

Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 2 - ROAD STRUCTURES, 2020) - page 7