02500 - Concrete Walkways

02500-1 Concrete Walkways

SECTION 02500 CONCRETE WALKWAYS 1. PART 1 - GENERAL 1.01 SECTION INCLUDES A. Cast-in-place concrete walkways and driveways in site

as shown on Drawings and as specified in this section. 1.02 REFERENCES A. ASTM - American Society for Testing and Materials ASTM A 184 Fabricated Steel Bar or Rod Mats for

Concrete Reinforcement ASTM A 185 Steel Welded Wire fabric, Plain, for

Concrete Reinforcement ASTM C 31 Standard Method of Making and Curing

Concrete Test - Specimen in the field ASTM C 33 Concrete Aggregates ASTM C 39 Compressive Strength of Molded Concrete

Cylinders ASTM C 94 Ready-Mixed Concrete ASTM C 150 Portland Cement ASTM C 171 Sheet Materials for curing Concrete ASTM C 309 Liquid Membrane-Forming Compounds for

Curing Concrete ASTM D 1751 Preformed Expansion Joint Fillers for

Concrete Paving and Structural Construction (Non-Extruding and Resilient Bituminous Types)

ASTM D 1850 Concrete Joint Sealer, Cold-applied type ASTM D 3569 Joint Sealant Hot-Poured Elastomeric, Jet

Fuel Resistant type for Portland Cement Concrete Pavements

B. ACI - American Concrete Institute ACI 117 Standard Tolerances for Concrete


Construction Material ACI 214 Recommended Practice for Evaluation of

Compression Test Results of Field Concrete ACI 304 Recommended Practice for Measuring, Mixing,

Transporting, and Placing Concrete ACI 305 Hot Weather Concreting ACI 308 Curing Concrete C. SASO - Saudi Arabian Standard SSA 142 Physical and Mechanical Methods of Testing

Portland Cement SSA 143 Portland Cement Ordinary and Rapid

Hardening D. AASHTO- American Association of State Highway and

Transportation Officials AASHTO M 182 Burlap Cloth Made from Jute or Kenaf E. Applicable requirements of this Specifications

specified in the following Sections: 1. Section 03100 - CONCRETE FORMWORK 2. Section 03200 - CONCRETE REINFORCEMENT 3. Section 03300 - CAST-IN-PLACE CONCRETE 1.03 SUBMITTALS A. Refer to the applicable requirements of the following

Sections of this Specifications: - Section 03100 - CONCRETE FORMWORK - Section 03200 - CONCRETE REINFORCEMENT - Section 03300 - CAST-IN-PLACE CONCRETE B. Samples: Provide 900 mm square slab showing finish for

concrete paving for approval. Locate mock-up where directed. Provide finish on paved areas were shown to match the approved sample mock-up. Retain mock-up protected from damage and staining until completion, final curing, and acceptance of Work. Remove mock-up(s) and dispose of before final completion of Work or when directed by the Engineer.


1.04 TRANSPORTATION, HANDLING AND STORAGE A. Refer to the applicable requirements of the following

Sections of this Specifications: - Section 03100 - CONCRETE FORMWORK - Section 03200 - CONCRETE REINFORCEMENT - Section 03300 - CAST-IN-PLACE CONCRETE 1.05 QUALITY ASSURANCE A. Refer to the applicable requirements of the following

Sections of this Specifications: - Section 03100 - CONCRETE FORMWORK - Section 03200 - CONCRETE REINFORCEMENT - Section 03300 - CAST-IN-PLACE CONCRETE 2. PART 2 - PRODUCTS 2.01 MATERIALS A. Formwork: conform to Section 03100 - CONCRETE FORMWORK,

unless specified otherwise,. B. Reinforcement: Conform to Section 03200 - CONCRETE

REINFORCEMENT, unless specified otherwise. Type and size shall be as shown on the Drawings.

C. Concrete: Conform to Section 03300 - CAST-IN-PLACE

CONCRETE unless specified otherwise. Provide Class 30 concrete (30 MPa compressive strength at 28 days) using Type v cement. Construct paving in conformance with details shown on Drawings. Provide final finish as indicated on Drawings.

D. Stamped Concrete: Manufacturer's standard materials and

tools to provide the required patterns as indicated on Drawings and as follows:

1. Color Hardener: Cement based, suitable for

application on fresh concrete slabs. 2. Color Release: Specially-formulated, iron oxide

based, release powder for application prior to stamping.


3. Clear Sealer: Acrylic resin liquid material,

suitable for application to cured slabs to protect stamped surfaces from discoloration, stains and moisture.

4. Stamping Tools: Manufacturer standard mats, to

provide the patterns indicated on Drawings after being tamped with special tamping machines.

E. Brick for Edging/Banding: Conform to the requirements

of Section 2515 - UNIT PAVERS. F. Vapor Barrier: Polyethylene sheets of thickness 250

micron and 150 mm overlapping for areas under concrete. G. Joint Filler: Asphalt saturated fiber board conforming

to ASTM D 1751. H. Joint Sealant: Cold applied, pourable, polyurethane-

based 2-component elastomeric sealant conforming to ASTM C 920, Type M, Grade P, Class 25 or FS-SS-S-200 or FS-SS-S-227 jet-fuel resistant.

3. PART 3 - EXECUTION 3.01 SUBGRADE PREPARATION A. Construct subgrade true to grades and cross-sections

shown on Drawings. Excavation, backfill, fill and compaction shall conform to requirements specified in Section 02200 - EARTHWORK. Check the compacted subgrade for grade and cross-section using template supported on side forms. Provide polyethylene vapor barrier sheets with minimum 150 mm overlapping before placing reinforcement and concrete.

3.02 FORM CONSTRUCTION A. Formwork shall conform to the requirements specified in

Section 03100 - CONCRETE FORMWORK. Set forms to the required grades and lines, rigidly braced and secured.

B. Check completed formwork for grade and alignment to the

following tolerances: 1. Grade: Plus or minus 3 mm. 2. Alignment: Plus or minus 6 mm at any point and no

more than 3 mm deviation from a 3 meter straight edge.


C. Clean forms after each use and coat with form release agent.

3.03 REINFORCEMENT A. Locate, place, and support reinforcement in conformance

with Section 03200 - CONCRETE REINFORCEMENT. 3.04 CONCRETE PLACEMENT A. Conform to the requirements of Section 03300 - CAST-IN-

PLACE CONCRETE for mixing, transportation and placing concrete and as specified herein.

B. Do not place concrete until subgrade and forms have

been checked for line and grade. Provide polyethylene sheet vapor barrier over subgrade before placing reinforcement and concrete. Do not place concrete around structures or frames until they have been brought to the required grade and alignment.

C. Place concrete in one course monolithic construction

for the full width and depth of walks, and in staggered and checkered manner.

D. Spread concrete as soon as it is deposited on the

subgrade using methods which prevent segregation of the mix. Consolidate concrete along the face of forms and adjacent to transverse joints with an internal vibrator. Keep vibrator away from joint assemblies, reinforcement, or side forms. Use square-faced shovels for hand spreading and consolidation. Consolidate with care to prevent dislocation of reinforcing and joint materials.

E. Strike-off fresh concrete and compact until a layer of

mortar is brought to the surface. Finish the surface to grade and cross section with a trowel smooth and/or broom finish as required. Perform concrete finishing using machine or hand method as approved by the Engineer. Broom transversely to the line of foot traffic. If necessary, apply water to the surface immediately before brooming. Broom finish shall match the approved sample.

F. Unless indicated otherwise on the drawings, mark the

surface of walks into rectangles measuring not less than 1 m² not over 2 m², unless approved otherwise. Use a scoring tool which leaves the edges rounded.

G. Concrete Curing: Conform to the requirements specified

in Section 03300 - CAST-IN-PLACE CONCRETE.


H. Hot Weather Placing: Conform to the requirements specified in Section 03300 - CAST-IN-PLACE CONCRETE.

3.05 STAMPED CONCRETE A. Concrete surfaces, indicated to receive a stamped

pattern shall be troweled to a smooth finish and left until concrete reaches a plastic stage.

B. Apply color hardener in 2 coats. Float surface using

Bull-Float after each coat, unless otherwise recommended by manufacturer.

C. Apply color release in one coat, same manner as above,

prior to stamping, unless otherwise recommended by manufacturer.

D. Stamping: Place stamping mats on concrete surfaces

according to the patterns indicated on the Drawings. Tamp mats using manufacturer standard methods and tamping machines.

E. Remove stamping mats. F. Second day after stamping, remove extra color release

and cut joints as recommended by manufacturer. Repair damaged areas as required.

G. After proper curing, depending on weather conditions,

apply clear sealer to stamped clean surfaces by roller or spray. Number of coats shall be as recommended by manufacturer and as appropriate for the intended application.

H. Do not allow traffic on all stamped areas until sealer

is applied and completely dry (second day after application as a minimum).

3.06 JOINTS A. General 1. Construct expansion, construction, isolation, and

contraction joints true-to-line with the face perpendicular to the surface of the walks.

2. Construct transverse joints at right angles to the

pavement centerline, unless otherwise indicated. B. Contraction Joints 1. Provide contraction joints, to section the walkway

into areas as shown on the drawings. Construct


weakened-plane joints to a depth equal to at least 1/4 the walkway thickness, as follows:

a. Tooled Joints: Form weakened-plane joints in

the fresh concrete by grooving the top portion of the slabs with a recommended cuttings tool and finishing edges with a joiner.

b. Saw Cut Joints: Saw cut to a width equal to 1/2

depth and fill with joint sealant. C. Construction Joints 1. Place construction joints at the end of pours and

at locations where placement operations are stopped for a period of more than 1/2 hour, except where such pours terminate at expansion joints.

2. Construct joints as shown on Drawings. Where not

shown, use standard metal keyway-section forms. D. Expansion and Isolation Joints 1. Provide 6 mm wide expansion joints at returns and

intervals not greater than 9 m along the walkway, unless otherwise indicated on the drawings.

2. Provide pre-molded joint filler for expansion

joints and isolation joints abutting concrete paving and curbs, gutters, catch basins, manholes, inlets, structures, walks, and other fixed objects.

3. Extend joint fillers full width and depth of the

joint, and not less than 12 mm or more than 25 mm below the finished pavement surface where joint sealer is indicated. If no joint sealer, place top of joint filler flush with finished concrete surfaces.

4. Use joint fillers in one-piece lengths for the full

width being placed wherever possible. Where more than one length is required, lace or clip joint filler sections together.

5. Protect the top edge of the joint filler during

concrete placement with a metal cap or other temporary material. Remove protection after both sides of joint are placed.

3.07 CURING A. Protect and cure finished concrete walks in conformance

with the requirements of Section 03300 - CAST-IN-PLACE


CONCRETE. Use moist-curing methods of initial curing whenever possible. After removal of forms, extend curing to exposed edges.

3.08 FIELD QUALITY ASSURANCE A. Conform to the applicable requirements specified in

Section 03300 - CAST-IN-PLACE CONCRETE. 3.09 REPAIR AND PROTECTION A. Repair or replace broken or defective walks as directed

by the Engineer. B. Protect the walks from damage until acceptance of the

Work. Exclude pedestrian traffic from walks for at least 14 days after placement.

C. Sweep concrete walkways and pavings, and wash free of

stains, discolorations, dirt, and other foreign material.

END OF SECTION

Documents

02500 - Concrete Walkways