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

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Second Edition -SEP 2020

4.4.4.3

Bonded Construction Joint

Epoxy resins specially designed for bonding old concrete to new shall be used at construction joints
where so specified and shown in the Contract plans. This epoxy shall consist of a 2-component liquid
polysulphide polymer epoxy resin concrete adhesive.

Preparation of the construction joint surface and the application of the epoxy resin shall be strictly in
accordance with the manufacturer's recommendations and the Engineer's instructions. Brand and
type of resin used shall be subject to the Engineer's approval.

The epoxy resin shall be applied strictly in accordance with the manufacturer’s recommendations to
avoid premature setting and forming a de-bonding film.

Bonded construction joints shall be made using the following procedures, unless otherwise specified:

1. After the concrete has hardened so that the header board or form can be removed without

damage to the concrete, it shall be removed and the cement paste removed from the surface
by washing with water under pressure or by sandblasting to expose clean, well-bonded
aggregate.

2. To facilitate the removal of the cement paste, the surface of the header board or form that shall

be  in  contact  with  the  first  pour  may  be  thoroughly  covered  with  a  retarder  consisting  of  a
ready-to-use  liquid  compound  that  delays  the  set  of  the  surface  concrete  approved  by  the
Engineer  prior  to  beginning  the  work.  Retarder  shall  produce  results  satisfactory  to  the
Engineer  and  shall  be  evaluated  on  the  basis  of  the  manufacturer's  data  and
recommendations.  When  the  retarder  is  used,  washing  with  water  under  pressure  shall  be
used to expose clean, well-bonded aggregate.

3. Prepared surface of the concrete shall be kept saturated with water until the new concrete is

placed, or it shall be saturated for a period of 4 hours before placing the new concrete.

4. Immediately prior to placing the new concrete, the forms shall be drawn tight against the

concrete already in place and the surface shall be covered with a thin coat of Class M6 mortar.

5. After the header board or form is removed and the concrete has cured, the second pour shall

be bonded to the first pour by the applying to the concrete joint surface a 2-component liquid
polysulphide polymer epoxy resin concrete adhesive.

6. Surface on which the adhesive is to be applied shall be free of oil, dirt, and loose concrete.

Unsound concrete shall be removed until a base of strong, undamaged concrete is exposed
on which to apply the adhesive. Deposits of dirt or oil products shall be removed by wire
brushing or sandblasting. Surfaces shall be free of moisture and dry before application of the
adhesive, which shall not be applied to newly placed concrete before the normal curing period
has elapsed.

7. Immediately before application, the two adhesive components shall be combined in the

proportions specified by the adhesive manufacturer. Components shall be intimately blended
by hand or with a slow speed motor drive mixing device. Next, the mixture shall be thinned by
adding and blending the solvent into the adhesive. Adhesives amounts mixed at one time shall
be limited to the quantity that can be conveniently applied within the pot life of the adhesive.

8. Two components and solvent shall not be mixed more than 30 minutes prior to use.

9. Adhesive shall be brushed onto the concrete in a layer 1 mm to 2 mm thick.

10. After the adhesive has been applied, concrete shall not be placed against it until the solvent

has evaporated: 30 min to 60 min, depending on weather conditions.

11. Adhesives shall be tacky and not dry at the time of concrete application. If an area becomes

dry, it shall be recoated before placing the concrete.

Because of toxicity of the materials, including the solvents, safety and health hazards exist in the
handling and use of the materials, and may cause serious rash in persons sensitive to the materials.

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Further, in the use of solvents as cleaning aids there exists a fire and flash hazard. Contractor shall
obtain from the material formulator complete instructions for safety, health, and handling precautions
with respect to the materials in use, and as to the procedure that shall be followed in the event that
workmen come in contact with the material. Before they are permitted to proceed with the work, the
workers shall be instructed as to the hazards to which they shall be exposed, the necessary safety
precautions and the procedure to be followed in the event of accidental contact with the materials.

4.4.4.4

Unbonded Construction Joints

Unbonded construction joints shall be made by forcing or striking off the previously placed concrete
to a true and even surface and allowing it to set. After the concrete has set, a bond breaker material
(refer to Article 4.3.15.7) shall be placed and secured on the old concrete. New concrete shall be
placed and thoroughly compacted to secure a close contact between the old and new concrete at all
points, separated only by the bond breaker material, with no attempt to secure a bonding of the new
concrete to the old work.

4.4.4.5

Expansion Joints

Expansion joints shall be located and formed as detailed in the Contract plans and specified herein.
Expansion joints shall be installed per the Contract plans or the Particular Specifications. Materials
meeting the requirements in Section 4.3.15 may be used, unless otherwise specified.

Expansion joints shall incorporate adequate protection against the entry of debris or other material
that may interfere with the closing of the joints in their construction.

Joint filler shall be cut to the same shape as that of the surfaces being jointed and shall be firmly
fixed against the surface of the concrete already in place in such a manner that it will not be displaced
when concrete is deposited against it. Immediately after form removal, the expansion joints shall be
carefully inspected, and any concrete or mortar that has sealed across the joint shall be neatly cut
and removed.

Application of approved sealers per Section 4.3.15 shall be in accordance with the manufacturer's
instructions.

Care shall be taken to prevent application of curing compound to locations where joint sealer is to
be placed.

Open joints shall be formed with a template made of wood, metal, or other suitable material. Insertion
and removal of the template shall be done without chipping or breaking the edges or otherwise
injuring the concrete.

Any part of an expansion joint running parallel to the direction of expansion shall provide a clearance
of at least 12 mm, produced by inserting and removing a spacer strip, between the two surfaces. To
prevent any wedging from expansion and Contraction, the Contractor shall ensure that the surfaces
are precisely parallel.

4.4.4.6

Installation of Fixed-joint Seals

Sealers  shall  be  installed  by  the  Contractor  using  suitable  hand  or machine  tools  and thoroughly
secured in place with an approved adhesive that shall cover both sides of the sealer over the full
area in contact with the sides of the joint. Adhesive may be applied to the sides of the joint or the
sealer or both. Sealers shall be installed in a compressed condition and shall at all times be below
the level of the surface by approximately the amount shown on the Contract plans. Sealers shall be
in one continuous piece for the full width of transverse joint prior to being installed in the joint and
shall have not more than 1 butt splice within its length, which shall be a manufacturer's splice. If this
splice  is  torn  or  damaged  it  shall  be  repaired,  prior  to  installation,  using  the  manufacturer's
recommended adhesive. In longitudinal joints the sealer shall be in practical lengths. Any joints in
the sealer material shall be adequately sealed with additional adhesive.

Any leakage of the joint shall be cause for rejection.

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Sealers shall be installed by the Contractor immediately after the removal of the curing cover, using
an adhesive that is compatible with the sealer and the material of which the joint surfaces are
composed. Temperature limitations of the adhesive, as guaranteed by the manufacturer, shall be
observed. Joints shall be clean and free of foreign material immediately prior to the installation of the
sealer.

No shipment of materials shall be accepted for use unless the material complies with the
requirements of Article 4.3.154.3.15.1.

Materials shall not be used until the Contractor has been notified by the Engineer that they meet the
requirements of these specifications.

4.4.5

Waterstops

Waterstops shall be furnished and installed in accordance with the details indicated on the Contract
plans, the provisions of Section 21.9.1.6 and Section 21.9.2.4 of Chapter 21, Concrete Structures,
of theses standard specifications, and as directed by the Engineer.

4.4.6

Concrete Protection Coating

All exposed items or surfaces not in contact with soil throughout concrete structures, except as
otherwise indicated on the Contract plans, shall be painted in accordance with Section 24.7 of
Chapter 24, Painting, of these standard specifications.

All exposed surfaces for concrete structures indicated on the Contract plans not to be painted or
waterproofed shall be sealed as per the requirements of Section 29.6 of Chapter 29, Miscellaneous
Items for Structures, of these standard specifications.

4.4.7

Reinforcing

Fabrication and installation of concrete reinforcement shall meet the applicable requirements of
Chapter 5, Reinforcing steel.

4.4.8

Concrete for Precast Elements

Precast concrete work shall be as indicated on the Contract plans, as specified herein, and as
directed by the Engineer. Tilt-up wall construction is allowed if so shown in the Contract plans and
shop drawings and approved by the Engineer.

All  precast  units  shall  be  manufactured  of  diverse  sizes  with  materials  as  specified  in  these
specifications and the  Contractor shall be responsible for transporting the same to the site of the
works.

Manufacturing plant for precast concrete units shall be inspected and approved by the Engineer for
the type of precast member to be produced prior to the start of production. This inspection and
approval shall be renewed annually during production, and the Engineer reserves the right to inspect
the plant at any time.

Quality control (QC) inspections shall be done by the Contractor while the Engineer shall perform
quality assurance (QA) inspections to facilitate the work and verify its quality. QA inspection shall
not relieve the Contractor of any responsibility for identifying and replacing defective material and
workmanship.

Contractor shall notify the Engineer prior to precasting concrete units.  Contractor shall provide the
Engineer with the opportunity to inspect the precast forms and units before, during, and after casting.
Prior to the start of production of the precast concrete units, the Contractor shall advise the Engineer
of  the  production  schedule  and  shall  give  the  Engineer  safe  and  free  access  to  the  work.  If  the
inspector  observes  any  non-specification  work  or  unacceptable  QC  practices,  the  Engineer  shall
advise the plant manager. If the corrective action is not acceptable to the Engineer, the units will be
rejected.

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Self-compacting concrete (SCC) may be used for precast concrete barriers and drainage items. If
the Engineer has approved the use of SCC, the consistency requirements in Section 4.3.11 shall not
apply. SCC is concrete that can flow under its own weight and completely fill the formwork, even in
the presence of dense reinforcement, without any vibration, while maintaining homogeneity. For
SCC, the following modified testing procedures for air content and compressive strength shall apply:

Moulds shall be filled completely in 1 continuous lift without any rodding, vibration, tamping, or

other consolidation methods other than lightly taping around the exterior of the mould with a
rubber mallet to allow entrapped air bubbles to escape

Fabricators’ QC testing shall include slump flow test results that demonstrate no segregation

Plant approval for use of SCC shall require the plant fabricator to cast 1 barrier or drainage

item and then sawed it in half for examination by the Engineer to determine that segregation
has not occurred.

4.4.8.1

Shop Drawings

Before precasting, the Contractor shall submit shop drawings for approval by the Engineer. These
shop drawings shall show complete details of the methods, materials, and equipment the Contractor
proposes to use in precasting work. Shop drawings shall follow the design conditions shown in the
Contract plans unless otherwise approved by the Engineer.

Shop drawings shall contain as a minimum:

1. Unit shapes, including elevations and sections, and dimensions

2. Finishes and method of constructing the finish, such as forming or rolling

3. Reinforcing, joint, and connection details

4. Lifting, bracing, and erection inserts

5. Locations and details of hardware attached to the structure

6. Relationship to adjacent material

Approval of these shop drawings shall not relieve the Contractor of responsibility for accuracy of the
drawings or conformity with the Contract. Approval shall not indicate a check on dimensions.

4.4.8.2

Casting

Plant, quality checking and approving procedures, casting process, curing, finishing, shop drawings,
and concrete mix shall be approved by the Engineer before the Contractor begins casting precast
concrete units. Manufacturer shall keep and make available to the Engineer the complete records of
all the concrete mixes and strength tests pertaining to each member cast. Contractor shall notify the
Engineer which members are to be cast in advance of the casting dates so that arrangements for
inspecting and testing the precast members can be made.

Concrete shall meet the requirements of Section 4.3.11 for annual preapproval of the concrete mix
design and slump.

Precast units shall not be removed from forms until the concrete has attained sufficient strength so
as not to sustain damage from the removal, typically a minimum compressive strength of 70 % of
the specified design strength, as verified by rebound numbers determined in accordance with ASTM
C 805M.

Precast units shall not be moved until the concrete has reached the specified design strength as
determined by testing cubes made from the same concrete as the precast units. Test cubes shall be
made, prepared and tested in accordance with Article 4.3.12.3.

Forms may be steel or plywood-faced, providing they impart the required finish to the concrete.

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4.4.8.3

Curing

Concrete in the precast units shall be cured by either moist or accelerated curing methods. Methods
to be used shall be preapproved by the Engineer.

1. For moist curing, the surface of the concrete shall be kept covered or moist until such time as

the compressive strength of the concrete reaches the strength specified for stripping. Exposed
surfaces shall be kept continually moist by fogging, spraying, or covering with moist burlap or
cotton mats. Moist curing shall commence as soon as possible following the completion of
surface finishing.

2. For accelerated curing, heat shall be applied at a controlled rate following the initial set of

concrete in combination with an effective method of supplying or retaining moisture. Moisture
may be applied by a cover of moist burlap, cotton matting, or other effective means. Moisture
may be retained by covering the unit with an impermeable sheet.

Radiant, convection, conducted steam, or hot air may be used to heat the concrete to no more than
37

C during the first 2 hours after pouring the concrete, and then increase by no more than 13° C

per hour to a maximum of 79

C. After curing is complete, the Contractor shall cool the concrete by

no more than 13° C per hour to 37

C. Contractor shall maintain the concrete temperature above 16

C until the unit reaches stripping strength.

Concrete temperature shall be monitored by means of a thermocouple embedded in the concrete
that is linked with a thermometer accurate to ±3° C. A recording sensor, accurate to ±3° C, shall be
arranged and calibrated to continuously record, date, and identify concrete temperature throughout
the heating cycle. This temperature record shall be made available to the Engineer for inspection
and become part of the required documentation.

Dry heat shall never be allowed to directly touch exposed unit surfaces at any point.

For tilt-up wall panels, Contractor shall moist-cure the panels for a minimum of 6 calendar days after
stripping the forms.

4.4.8.4

Contractor

’s Control Strength

All sections referring to cast-in-situ concrete shall apply to precast concrete. In addition, the
Contractor shall satisfy the Engineer that the precast concrete units are not moved or loaded until
they have attained the required strength.

Concrete strength at stripping and the verification of design strength shall be determined by testing
cubes made from the same concrete as the precast units.

Concrete acceptance and testing shall meet the applicable requirements of Section 4.3.12.

For accelerated cured units, concrete strength shall be measured on test cubes cast from the same
concrete as that in the unit. These cubes shall be cured under time-temperature relationships and
conditions that simulate those of the unit. If the forms are heated by steam or hot air, test cubes shall
remain in the coolest zone throughout curing. If forms are heated another way, the Contractor shall
provide a record of the curing time-temperature relationship for the cubes for each unit to the
Engineer. When 2 or more units are cast in a continuous line and in a continuous pour, a single set
of test cubes may represent all units provided the Contractor demonstrates uniformity of casting and
curing to the satisfaction of the Engineer.

Enough cubes shall be moulded, cured, and tested by the Contractor to satisfy specification
requirements for measuring concrete strength. Contractor shall let cubes cool for at least 30 minutes
before testing for release strength.

Test cubes may be cured in a moist room or water tank in accordance with AASHTO T 23, after the
unit concrete has obtained the required release strength. If the Contractor intends to ship the unit
prior to the standard 28-day strength test, the design strength for shipping shall be determined from
cubes placed with the unit and cured under the same conditions as the unit. These cubes may be
placed in a non-insulated, moisture-proof envelope.

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To measure concrete strength in the precast unit, the Contractor shall randomly select 2 test cubes
and average their compressive strengths. Compressive strength in either cube shall not fall more
than 5 % below the specified strength. If these 2 cubes do not pass the test, 2 other cubes shall be
selected and tested.

All test results and certifications shall be kept at the fabricator’s facility for the duration of the works
for review by the Engineer or the Owner.

4.4.8.5

Finishing and Marking

On removal from the forms, the precast concrete units shall be examined and all surfaces that will
be permanently visible shall have a smooth and dense finish or uniform texture free from holes, fins,
and shutter staining. Any precast concrete unit that is found to be defective in any respect shall be
rejected.

For the purposes of identification, all members shall be marked with paint in neat lettering with the
member number shown on the drawings or as agreed on and an identification number relating to the
manufacturing records.

4.4.8.6

Tolerances

Units shall be fabricated to the dimensions and tolerances shown in the drawings, and shall meet
the dimensional tolerances listed in the latest edition of PCI-MNL-166, unless otherwise required by
the Contract plans or Particular Specifications.

4.4.8.7

Handling and Storage

Units shall be so stored, transported, and fixed to avoid overstressing or damage at any time.

All units shall be lifted only by adequate devices at locations designated on the shop drawings.

Precast units shall be stored off the ground on foundations suitable to prevent differential settlement
or twisting. Stacked units shall be separated and supported by dunnage of uniform thickness capable
of supporting the units. Dunnage shall be arranged in vertical planes. Upper units of a stacked tier
shall not be used as storage areas for shorter units unless substantiated by Engineering analysis
and approved by the Engineer.

Tilt-up wall construction is allowed if so shown in the Contract plans and approved shop drawings.

For tilt-up wall construction, the Contractor will erect the wall panels in place by tilting them up to
their permanent location, temporarily bracing the panels in place, completing the permanent
connections required to secure the precast tilt-up panel, and finally removing the temporary supports.

4.4.8.8

Shipping

Precast units shall not be shipped until the concrete has reached the specified design strength and
the Engineer has reviewed the fabrication documentation for Contract compliance and stamped the
pre

cast concrete units “approved for shipment”. Units shall be supported in such a manner that they

shall not be overstressed or damaged during transport or by anticipated impact of their dead load.
Sufficient padding material shall be provided between tie chains and cables to prevent chipping or
spalling.

4.4.8.9

Erection

When the precast units arrive on the project, the Engineer shall confirm that they are stamped
“Approved for shipment.” Precast units shall be evaluated by the Engineer for damage before they
are accepted.

All units shall be lifted by suitable devices at locations designated on the shop drawings. Temporary
shoring or bracing shall be provided, if necessary. Units shall be properly aligned and levelled, as
required by the drawings. Variations between adjacent units shall be levelled out by a method
approved by the Engineer.

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Markings shall be so positioned as not to be visible when the structural member is placed in its final
position in the completed structure.

All precast members that have been chipped, cracked, warped, or otherwise damaged to the extent
that such damage will, in the opinion of the Engineer, prejudice the appearance, function, or
structural integrity of the members shall be rejected or, where so allowed, repaired to the satisfaction
of the Engineer.

4.4.9

Waterproofing

This work shall consist of applying waterproofing materials to cementitious concrete surfaces, as
required by the Contract plans and these Standard Specifications.

All surfaces of concrete structures in contact with soil or backfill shall be protected in accordance
with Section 28.2 of Chapter 28, Waterproofing, of these standard specifications.

All concrete structures that require water-tightness shall be waterproofed in accordance with Section
28.3 of Chapter 28, Waterproofing, of these standard specifications.

4.5

Self-Consolidating Concrete (SCC)

4.5.1

Definitions

a. Self-Consolidating Concrete (SCC): A highly flowable, non-segregating concrete that can

spread into place, fill the formwork, and encapsulate the reinforcement without any mechanical
consolidation.

b. Passing Ability: The ability of SCC to flow under its own weight (without vibration) and fill

completely all spaces within intricate formwork, containing obstacles, such as reinforcement.

c. J-Ring Test: Test used to determine the passing ability of SCC, or the degree to which the

passage of concrete through the bars of the J-Ring apparatus is restricted.

d. J-Ring Flow: The distance of lateral flow of concrete using the J-Ring in combination with a

slump cone.

e. Slump Flow: Test method used to measure the unconfined flow and stability of SCC using a

slump cone (upright or inverted).

f. Slump Flow Spread: The numerical value in mm of flow determined as the average diameter

of the circular deposit of SCC at the conclusion of the slump test.

g. T

Value: Time (in seconds) the edge of the concrete mass takes to reach 500 mm diameter

from the time the mold is first raised in the slump flow test.

h. Stability: The ability of a concrete mixture to resist segregation of the paste from the

aggregates.

i. Static Segregation (Segregation Factor): Segregation of the mortar from the coarse aggregate

that occurs after placement while the concrete is still in a plastic state.

j. Visual Stability Index (VSI) Rating: An assessment of the homogeneity of concrete based on

the visual inspection of the concrete sample at the end of the slump flow test.

4.5.2

Quality Assurance

1. In accordance with ACI 301M-10 for mixing, transportation and placing of concrete.

2. In accordance with ACI 305.1-06 for hot weather concrete placement and protection.

3. In accordance with ACI 308.1-11 for curing.

4. In accordance with ACI 301M-10 for concrete consolidation.

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5. Testing and Inspection Agency Qualifications: Independent agency conforming to the

requirements of ASTM E329 - 13b.

4.5.3

Materials

The materials shall be suitable for the intended use in concrete and not contain harmful ingredients
in such quantities that may be detrimental to the quality or the durability of the concrete, or cause
corrosion of the reinforcement.

a. Portland cement shall conform to ASTM C150 / C150M - 12, Type I, II, I/II, III, and V.

b. Fine and coarse aggregates shall conform to ASTM C33 / C33M - 13.

c. Water shall conform to ASTM C1602 / C1602M

– 12.

d. Admixtures shall be furnished from one manufacturer:

1. Characteristics: Compatible with each other and free of intentionally-added chlorides.

2. Air-Entraining Admixture: Shall conform to ASTM C260 / C260M - 2010a.

3. Water-Reducing Admixture: Shall conform to ASTM C494 / C494M

– 2011, Type A.

4. Mid-Range Water-Reducing Admixture: Shall conform to ASTM C494 / C494M

– 2011,

Type A.

5. High-Range Water-Reducing Admixture: Shall conform to ASTM C494 / C494M

– 2011,

Type F (or ASTM C1017 / C1017M

– 07, Type I).

6. Accelerating Admixture: Shall conform to ASTM C494 / C494M

– 2011, Type C or E.

7. Retarding Admixture: Shall conform to ASTM C494 / C494M

– 2011, Type B or D.

8. Hydration Control Admixture: Shall conform to ASTM C494/C494M

–2011, Type B or D.

9. Workability-Retaining Admixture:

i. Shall retain concrete workability without affecting time of setting or early age strength

development.

ii. Shall conform to ASTM C494 / C494M

– 2011, Type S.

10.

Permeability-Reducing Admixture:

i. Shall be an integral crystalline capillary waterproofing admixture for concrete.

ii. Shall satisfy the following requirements, when used at the

manufacturer’s

recommended dosage:

•

Reduction in capillary absorption: Not less than 40 percent relative to a companion

untreated concrete mixture, when tested in accordance with ASTM C 1585 - 13.

•

Reduction in water penetration: Not less than 40 percent relative to a companion

untreated concrete mixture, when tested in accordance with DIN 1048-5.

•

The admixture shall not affect the setting time, strength or durability properties of

concrete.

11.

Viscosity-Modifying Admixture:

Shall conform to ASTM

C494

C494M

–

2011, Type S.

12.

Corrosion-Inhibiting Admixture: Shall be a nominal 30% solution of calcium nitrite

or an amine/ester

– based organic corrosion – inhibiting admixture.

13.

Shrinkage-Reducing Admixture: Shall conform to ASTM C494 / C494M

– 2011,

Type S.

14.

Alkali-Silica Reaction Inhibiting Admixture:

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i. Shall contain a nominal lithium nitrate content of 30 percent.

ii. Shall conform to ASTM C494 / C494M

– 2011, Type S.

15.

Other admixtures shall be approved by the Engineer.

e. Supplementary Cementitious Materials (SCM):

1. The substitution of supplementary cementitious materials for cement shall be made on the

basis of mass.

2. Fly Ash: Shall conform to ASTM C618 - 2008.

3. Slag Cement: Shall conform to ASTM C989 / C989M - 12a.

4. Silica Fume: Shall conform to ASTM C1240 - 12.

5. Metakaolin: Shall conform to ASTM C618 - 2008, Class N.

f. Fibers:

1. Microsynthetic Fibers:

i. Shall conform to ASTM C1116 / C1116M - 10a.

ii. Shall provide a minimum crack reduction ratio (CRR) of 40% when tested in accordance

with ASTM C1579 - 13.

2. Macrosynthetic Fibers:

i. Shall conform to ASTM C1116 / C1116M - 10a.

ii. Shall have an equivalent flexural strength ratio as recommended by the manufacturer

and approved by the Engineer, and tested in accordance with ASTM C1609 /
C1609M - 12. Or

iii. Shall have toughness as recommended by the manufacturer and approved by the

Engineer, and tested in accordance with ASTM C1550 - 12a.

3. Steel Fibers:

i. Shall conform to ASTM A820 / A820M - 11.

ii. Shall have an equivalent flexural strength ratio as recommended by the manufacturer

and approved by the Engineer, and tested in accordance with ASTM C1609 /
C1609M - 12. Or

iii. Shall have toughness as recommended by the manufacturer and approved by the

Engineer, and tested in accordance with ASTM C1550 - 12a.

Dosage of fibers for composite steel decks shall not be less than 2.4 kg/m3 for
macrosynthetic fibers and 14.8 kg/m3 for steel fibers, as recommended in ANSI/SDI
C

– 2011.

g. Evaporation Reducer:

16.

Shall be a monomolecular film-forming liquid for application to fresh concrete

prevent rapid drying of the surface.

17.

Evaporation reducer shall not be used as a finishing aid.

4.5.4

Concrete Mixtures

The Contractor shall furnish to the Engineer a mixture proportion for the SCC to be used.

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•

Proportion mixture shall be in accordance with the particular specifications (Compressive

Strength, Air Content, Slump Flow, T50, VSI, J-Ring Value and Segregation Factor).

•

The Contractor shall use the same components in the trial batches as that to be used in the

Project including coarse and fine aggregates, inert non-cementitious fillers, water, source and
type of cement, supplementary cementitious materials and admixtures including any site-
added admixtures intended to be used.

4.5.4.1

Mixture Specifications

•

Water-to-cementitious materials ratio shall not exceed 0.45 by mass.

•

Supplementary Cementitious Materials: Fly ash or other pozzolans and silica fume shall not

constitute more than 25 and 10 percent, respectively, of the total mass of cementitious
material.

4.5.4.2

Slump Flow

•

Slump flow shall be measured in accordance with ASTM C1611 / C1611M - 09be1.

•

Typical ranges of slump flow are outlined in Table 4-31.

•

The design slump flow of the SCC mixture shall be established after consideration of the

Project requirements.

•

The slump flow of SCC used on the Project shall be the design slump flow plus or minus 50

mm.

Table 4-31: Typical ranges of slump flow

Type of Construction

Range of Slump Flow Values

Slabs

500-750

Architectural members

600-750

Wall, lightly reinforced

500-750

Column or wall, densely reinforced

600-750

Drilled Shafts

500-600

4.5.4.3

Visual Stability Index (VSI)

VSI Rating (in accordance with ASTM C1611 / C1611M - 09be1) shall not exceed 1.

4.5.4.4

J-Ring Flow

Difference between slump flow and J-Ring flow (as measured by ASTM C1621 / C1621M - 09b)
shall not be more than 50 mm.

4.5.4.5

Stability

The stability of the concrete shall be determined in the laboratory prior to approval of the SCC mixture
using test method ASTM C1610 / C1610M - 10. Concrete mixtures shall have a maximum static
segregation (segregation factor) of 15 percent.

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4.5.4.6

Air content

Air content shall

less

than

3%, as recommended by the manufacturer, and as approved by the

Engineer.

4.5.4.7

Maximum nominal size of coarse aggregate

1. Not larger than 1/5 the narrowest dimension between sides of forms.

2. Not larger than 1/3 the depth of slabs.

3. Not larger than ¾ of the minimum clear spacing between individual reinforcing bars or wires,

bundles of bars, individual tendons, bundled tendons, or ducts.

4. Maximum size of aggregate shall be 20 mm.

4.5.5

Execution

4.5.5.1

Formwork

Concrete formwork shall be in accordance with Section 4.6. Additional measures shall be taken to
seal the formwork to prevent leakage of cement paste or mortar.

4.5.5.2

Batching

Materials shall be batched in accordance with ASTM C94 / C94M - 13a and ASTM C1116 / C1116M
- 10a.

In addition to the use of a moisture probe, the moisture content of the aggregates shall be determined
once a day prior to batching in accordance with ASTM C70

– 13 or ASTM C566 - 13. Aggregate

samples shall be taken as close as possible to the area where moisture probe is located. Use of
microwave oven or hot plate to dry the aggregates is permitted in addition to using an oven.

Volume of concrete batched shall be such that no spillage occurs during transport.

4.5.5.3

Transporting

Concrete shall be transported in accordance with ASTM C94 / C94M - 13a and ASTM C1116 /
C1116M - 10a.

4.5.5.4

Hot Weather Concreting

Concrete shall be placed and protected in accordance with ACI 305.1-06.

4.5.5.5

Field Quality Control

The Contractor shall provide the following:

1. Provide adequate facilities for safe storage and proper curing of concrete test cylinders onsite

for the first 24 hours or for additional time as may be required before transporting samples to
the test lab.

2. Provide concrete for testing of slump flow, air content, density (unit weight) and temperature

and, for making cylinders.

3. Water

shall

not

added

the

concrete

the

job

site.

4. Field addition of admixtures, if needed for logistics reasons, shall be approved by the Engineer.

The Contractor shall consult with the admixture manufacturer in developing quality control operations
appropriate to the Project.

Field testing and inspection shall be performed in accordance with ACI 301M-10.

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Concrete tests shall be conducted by an ACI Concrete Field Testing Technician Grade I, or
equivalent, knowledgeable in testing self-consolidating concrete.

Tests shall be conducted on the first batch of the day and for each 110 m

or fraction thereof, for

each concrete mixture placed in any one day.

The testing agency provided by the Contractor and approved by the Owner and the Engineer shall
provide the following services:

a. Inspect concrete placement.

b. Sample the concrete in accordance with ASTM C172 / C172M - 10.

c. Test concrete slump flow in accordance with ASTM C1611 / C1611M - 09be1. Cone can either

be used upright or inverted. Same procedure shall be followed throughout the Project.

d. Record the Visual Stability Index (VSI).

e. Test passing ability in accordance with ASTM C1621 / C1621M - 09b. Cone shall be used in

the same way as in slump flow test.

f. Determine the air content of concrete sample for each strength test in accordance with ASTM

C231 / C231M

– 10 or ASTM C173 / C173M - 12, except that the concrete shall be filled in

one lift and not consolidated. Light tamping of the sides of the air-meter is permitted.

g. Determine the density (unit weight) of concrete sample for each strength test in accordance

with ASTM C138 / C138M - 13a, except that the concrete shall be filled in one lift and not
consolidated.

h. Record the temperature of concrete for each strength test in accordance with ASTM C1064 /

C1064M - 12.

i. Cast concrete specimens for compressive strength test as follows:

Cast and cure at least three 150 mm by 300 mm cylinders or four 100 mm by 200 mm cylinders
in accordance with ASTM C31 / C31M - 12, except that the concrete shall be placed in one lift
and not consolidated. However, light tapping of the sides of the cylinders with an open hand is
permitted. Number of cylinders to be cast may be adjusted if strength tests at other than
standard ages are required.

j. Record the fresh concrete data for each set. The datasheet shall include the following:

1. Mixture number

2. Specified 28-day strength

3. Date and time of batching

4. Time of testing

5. Location of placement

6. Truck number

7. Ticket number

8. Slump flow, VSI, passing ability, air content, density (unit weight) and temperature of

concrete

9. Ambient temperature

10. Names and quantities of admixtures added on site, and, name and title of the person who

authorized the addition

11. Set number, if more than one set of cylinders are cast on a single day

12. Name of the testing agency

13. Name and signature of the inspector who conducted the test, and

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14. Any additional observations or comments.

k. Mark the cylinders and write the date of casting on each cylinder.

l. Store and protect the cylinders at the job site immediately after casting in accordance with

ASTM C31 / C31M - 12.

m. Transport the cylinders from job site to the laboratory in accordance with ASTM C31 / C31M

–

12 after the cylinders have attained acceptable strength.

n. Cure the cylinders in the laboratory in accordance with ASTM C31 / C31M - 12.

o. Test cylinders for compressive strength in accordance with ASTM C39 -C39M 2011.

1. Test one cylinder at 7 days for information and at least two cylinders at 28 days for

acceptance when testing 150 mm by 300 mm cylinders unless otherwise specified.

2. Test one cylinder at 7 days for information and at least three cylinders at 28 days for

acceptance when testing 100 mm by 200 mm cylinders unless otherwise specified.

Tests at other ages may be specified as necessary.

p. Base strength value on the average of at least two 150 mm by 300 mm cylinders or three 100

mm by 200 mm cylinders tested at 28 days.

q. Test report shall include all the information in Item 10 above and compressive strength data,

and shall be signed by the laboratory manager.

r. Strength of concrete shall be deemed satisfactory if both of the following requirements are met

(ACI 318M -11):

1. Every arithmetic average of any three consecutive compressive strength tests equals or

exceeds the specified compressive strength, and

2. No compressive strength test falls below the specified compressive strength by more than

3.5 MPa when the specified strength is 35 MPa or less; or by more than 10 percent of
specified strength, when the specified strength is above 35 MPa.

If any strength test of laboratory-cured cylinders falls below the specified compressive
strength by more than the values specified above, remedial measures shall be taken as
recommended by the Engineer.

4.5.5.6

Consolidation

Consolidation is typically not necessary for SCC. However, the Contractor shall have internal
vibrators as recommended in ACI 301M-10 on site in case internal vibration is needed due to delays
in placement or the concrete has a lower than expected slump flow and has to be placed to prevent
the formation of a cold joint.

Prior approval by the Engineer shall be obtained if minimal vibration (external or internal) is required
for proper consolidation due to congested reinforcement or space restrictions.

4.5.5.7

Finishing

Concrete finishing shall be in accordance with Section 4.4.3 and Article 4.4.8.5.

4.5.5.8

Curing and Protection

Curing and protection of concrete shall be in accordance with ACI 308.1-11.

4.6

Formwork

Forms  are  temporary  works  that  shall  comply  with  the  requirements  of  Section  1.20,  Chapter  1,
General  Requirements,  of  these  standard  specifications.  Materials  and  design  requirements  for
forms  shall  be  in  accordance  with  Article  1.20.8.2  and  Article  1.20.8.4  of  Chapter  1,  General

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Requirements. Construction requirements for formworks shall be in accordance with Section 4.6.2,
and removal of formwork shall be in accordance with the requirements of Section 4.6.3.

Slip-form formwork shall comply with the requirements of Section 4.6.1 and Article 4.6.2.5. The
Contractor shall receive Engineer’s approval of slip-form formwork prior to fabrication or bringing the
slip-form equipment to the site of the works.

4.6.1

Slip-form Formwork

4.6.1.1

Timber Connections

Timber connections shall be designed in accordance with the methods, stresses, and loads allowed
in the Timber Construction Manual, Fifth Edition by the American Institute of Timber Construction
(AITC), or equivalent as approved by the Engineer. Frictional resistance shall not be considered as
contributing to the stability of any timber connection.

4.6.1.2

Bolted Connections

Tabulated values in the

AITC Timber Construction Manual-Fifth Edition

are based on square posts.

For a round post or pile, the main member thickness shall be the side of a square post having the
same cross-sectional area as the round post used.

Design values for bolts are typically given for load is applied either parallel or perpendicular to the
direction of the wood grain. For load is applied at an angle to the grain, the design value for the main
member shall be obtained from the Hankinson formula shown in the AITC manual. Design values in
the AITC Table 6.20 apply only to 3-member joints (bolt in double shear) in which the side members
are each ½ the thickness of the main member.

Threaded rods and coil rods may be used in place of bolts of the same diameter with no reduction
in the tabulated values. At openings for roadways and railroads, all connections shall be bolted using
15mm diameter or larger through bolts.

Bolt holes shall exceed the bolt diameter by 0.8 mm to 3 mm. A washer not less than a standard cut
washer shall be installed between the wood and the bolt head and between the wood and the nut to
distribute the bearing stress under the bolt head and nut and to avoid crushing the fibres. In lieu of
standard cut washers, metal plates or straps with dimensions at least equal to that of a standard cut
washer may be substituted.

When steel bars or shapes are used as diagonal bracing, the tabulated design values shown in AITC

Table 6.20 for the main members loaded parallel to grain (P value) are increased 75 % for joints
made with bolts 12 mm or less in diameter, 25 % for joints made with bolts 38 mm in diameter, and
proportionally for intermediate diameters. No increase in the tabulated values is allowed for
perpendicular-to-grain loading (Q value).

Clearance requirements for end, edge, and bolt spacing distance shall be as shown below. All
distances are measured from the end or side of the wood member to the center of the bolt hole. For
members which are subject to load reversals the larger controlling distances shall be used for design.
For parallel-to-grain loading, the minimum distances for full design load:

•

In tension, minimum end distance shall be 7 times the bolt diameter

•

In compression, minimum end distance shall be 4 times the bolt diameter

•

In tension or compression, the minimum edge distance shall be 1.5 times the bolt diameter.

For perpendicular-to-grain loading, the minimum distance for full design load:

1. Minimum end distance shall be 4 times the bolt diameter

2. Edge distance toward which the load is acting shall be at least 4 times the bolt diameter

3. Distance on the opposite edge shall be at least 1.5 bolt diameters

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Minimum spacing between adjacent bolts in a row shall be 4 times the bolt diameter, measured
centre-to-centre of the bolt holes.

When more than 2 bolts are used in a line parallel to the axis of the side member, additional
requirements shall be followed as shown in the AITC manual.

a. Lag Screw Connections

Design values for lag screws subject to withdrawal loading can be found in AITC

Table 6.27. An

equivalent standard may be used with the approval of the Engineer. Maximum load on a given screw
shall not exceed the allowable tensile strength of the screw at the root section.

If subjection of lag screws to end-grain withdrawal loading cannot be avoided, the design value shall
be 75 % of the corresponding value for withdrawal from the side grain.

When the load is applied at an angle to the grain, the design value shall be obtained from the
Hankinson formula shown in the AITC manual. When lag screws are subjected to a combined lateral
and withdrawal loading, as would be the case with longitudinal bracing when the falsework bents are
skewed, the effect of the lateral and withdrawal forces shall be determined separately. Withdrawal
component of the applied load shall not exceed the allowable value in withdrawal. Lateral component
of the applied load shall not exceed the allowable lateral load value. Lag screws shall be inserted in
lead holes as follows:

1. Clearance hole for the shank shall have the same diameter as the shank, and the same depth

of penetration as the length of unthreaded shank

2. Lead hole for the threaded portion shall have a diameter equal to 60 % to 75 % of the shank

diameter and a length equal to at least the length of the threaded portion. Larger percentile
figure in each range shall apply to screws of the greater diameters used in Group II wood
species

3. Threaded portion of the screw shall be inserted in its lead hole by turning with a wrench, not

by driving with a hammer

4. To facilitate insertion, soap or other lubricant shall be used on the screws or in the lead hole.

b. Drift Pin and Drift Bolt Connections

When drift pins or drift bolts are used, the required length and penetration shall be determined using
the following criteria. Lateral load-carrying capacity of drift pins and drift bolts driven into the side
grain of a wood member shall be limited to 75% of the design values for a common bolt of the same
diameter and length in the main member. For drift pin connections, the pin penetration into the
connected members shall be increased to compensate for the absence of a bolt head and nut. For
drift bolts or pins driven into the end grain of a member, the lateral load-carrying capacity shall be
limited to 60 % of the allowable side grain load (perpendicular to grain value) for an equal diameter
bolt with nut. To develop this allowable load, the drift bolt or pin shall penetrate at least 12 diameters
into the end grain. To fully develop the allowable load of the drift bolts or pins, they shall be driven
into predrilled holes, 1.5mm less in diameter than the drift pin or bolt diameter.

Criteria shown in the AITC Timber Construction Manual-Fifth Edition shall apply to drift bolt or pin
connection allowable loads for the following conditions:

1. Withdrawal resistance; and

2. When there are more than 2 drift bolts or pins in a joint, allowable loads shall be further reduced

by applying applicable modification factors shown in the AITC Table 6.3.

4.6.1.3

Nailed and Spiked Joints

Joints using nails or spikes shall conform to the provisions of AITC. End grain withdrawal shall not
be used. Diameters listed in the tables apply to fasteners before application of any protective coating.

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Second Edition -SEP 2020

When more than 1 nail or spike is used in a joint, the total design value for the joint in withdrawal or
lateral resistance shall be the sum of the design values for the individual nails or spikes.

Tabulated design values for lateral loads are maximum values for the type and size of fastener
shown. Tabulated values shall not be increased even if the actual penetration is exceeded. When
main member penetration is less than required, the design value shall be determined by straight-line
interpolation between zero and the tabulated load, except that penetration shall not be less than 1/3
of that specified.

Double-headed or duplex nails used in formwork construction are shorter than common wire nails or
box nails of the same size designation. They have less penetration into the main member and
therefore their load-carrying capacity shall be adjusted accordingly.

Nail and spike minimum spacing in timber connections shall be as follows:

a. Average center-to-center distance between adjacent nails, measured in any direction, shall not

be less than the required penetration into the main member for the size of nail being used

b. Minimum end distance in the side member, and the minimum edge distance in both the side

member and the main member, shall not be less than ½ of the required penetration

Allowable values for withdrawal and lateral load resistance are reduced when toe nails are used in
accordance with the following:

1. For withdrawal loading, the design load shall not exceed 2/3 of the value shown in the

applicable design table

2. For lateral loading, the design load shall not exceed 5/6 of the value shown in the applicable

design table

Toe nails are recommended to be driven at an approximate angle of 30-degrees with the piece and
started approximately 1/3 of the length of the nail from the end or side of the piece.

4.6.1.4

Timber Connection Adjustment for Duration of Load

Tabulated values for timber fasteners are for normal duration of load and may be increased for short
duration loading, except for connections used in formwork for staged construction sequences.

Duration  of  load  adjustment  for  timber  connections  shall  not  be  allowed  for  staged  construction
sequences  where  delayed  and/or  staged  loading  occurs  for  any  type  of  concrete  structure.
Adjustment for duration of load as described in this section applies only to design values for timber
connectors,  such  as  nails,  bolts,  and  lag  screws,  not  for  timber  and  structural  steel  components.
Tabulated values for nails, bolts, and lag screws may be adjusted by the following duration-of-load
factors:

•

1.25 for falsework design governed by the minimum design horizontal load or greater (3 % or

greater of the dead load)

•

1.33 for falsework design governed by wind load

•

2.00 for falsework design governed by impact loading

4.6.1.5

Face Lumber, Studs, Wales, and Metal Forms

Elements of this section shall be designed for the required loads, deflections, and conditions. Forms
battered or inclined above the concrete shall have positive anchorage or counterweights designed
to resist uplift as concrete is placed. Anchorages shall be shown in the formwork drawings.

Where the concrete pouring sequence causes fresh concrete to be significantly higher along one
side of tied forms than the opposite side, a positive form anchorage system capable of resisting the
imbalance of horizontal thrust, and preventing the dislocation and sliding of the entire form unit, shall
be designed and installed.

Abu Dhabi, United Arab Emirates. STANDARD CONSTRUCTION SPECIFICATIONS (PART 1 - ROADS, Second Edition 2020) - page 27