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December 2010 DIVISION 4 - CW 3135 – R1

CW 3135 – SUPPLY AND INSTALLATION OF GEOGRID

TABLE OF CONTENTS

1. DESCRIPTION........................................................................................................................1

1.1

General ................................................................................................................1 1.2 Definitions ............................................................................................................1

1.3 Referenced Standard Construction Specifications ..............................................1

2.

MATERIALS ............................................................................................................................1

2.1 Approved Products ..............................................................................................1

2.2 Material Identification...........................................................................................1

2.3 Storage and Handling ..........................................................................................1

2.4 Mill Certificate and MARV Data ...........................................................................1

2.5 Geogrid ................................................................................................................2

3. CONSTRUCTION METHODS ................................................................................................2

3.1 Geogrid ................................................................................................................2

4. MEASUREMENT AND PAYMENT .........................................................................................3 4.1 Geogrid ................................................................................................................3

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December 2010 Page 1DIVISION 4 - CW 3135-R1

CW 3135 – SUPPLY AND INSTALLATION OF GEOGRID

1. DESCRIPTION

1.1 General

.1 This specification covers the supply and installation of geogrid on unstable sub-grade soilconditions.

1.2 Definitions

.1 Average Tensile Strength – The average ultimate strength of Machine Direction and TransverseDirection

.2 Junction Efficiency – The Junction Strength divided by Ultimate Tensile Strength multiplied by100.

1.3 Referenced Standard Construction Specifications

.1 CW 3110 – Sub-grade, Sub-base and Base Course Construction

.2 CW 3130 – Supply and Installation of Geotextile Fabrics.

.3 Approved Products for Surface Works

2. MATERIALS

2.1 Approved Products

.1 Use only those materials listed as Approved Products for Surface Works. The ApprovedProducts are available in Adobe acrobat (.pdf) format at the City of Winnipeg, Corporate Finance,Material Management Internet site at: http://www.winnipeg.ca/matmgt/info.stm

2.2 Material Identif ication

.1 Geogrid is to be labelled in accordance with ASTM D 4873 and must clearly show themanufacture’s product style number and unique roll number.

2.3 Storage and Handling

.1 Store and handle in accordance with the manufacturer’s and/or supplier’s recommendations.

.2 The protective covering is to remain on the geogrid roll until installation.

.3 Protect the geogrid from exposure to ultraviolet light during storage.

.4 Protect the geogrid from contamination of dirt, dust and any other deleterious materials.

2.4 Mill Certifi cate and MARV Data

.1 Provide the Mill Certificate and MARV (Minimum Average Roll Value) Data in accordance with ASTM D 4759 upon request by the Contract Administrator.

http://www.winnipeg.ca/matmgt/info.stm

http://www.winnipeg.ca/matmgt/info.stm

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2.5 Geogrid

.1 Geogrid will be extruded polypropylene, bi-axial, single layer with opening configuration eithersquare or rectangular in shape.The axis with the least strength will be taken as the ultimate strength of the geogrid.

Table CW 3135.1 – Geogr id Property Requirements

Physical Property Requirements Test Method

Ultimate Tensile Strength 17.5 kN-m minimum ASTM D 6637

Average Tensile Strength 24 kN-m minimum ASTM D 6637

Junction Efficiency 90% minimum GRI GG2

Tensile Strength @ 2% Strain 6.0 kN-m minimum ASTM D 6637

Aperture Size 25 – 40 mm Direct Measure

Flexural Rigidity 250,000 mg-cm minimum ASTM D 1388

3. CONSTRUCTION METHODS

3.1 Geogrid

.1 Unroll geogrid as smooth as possible on the non-woven separation fabric and prepared sub-grade, in the direction of construction traffic. Install the geogrid in the longest continuouspractical length, free from tension, stress, folds, wrinkles and creases.

.2 Overlap joints a minimum of 900mm.

.3 Tie adjacent rolls with joint fasteners in accordance to the manufacturer’s recommendations.

.4 Construction vehicles are not permitted directly on the geogrid.

.5 Place and compact sub-base material to a minimum depth of 300mm in accordance with CW3110.

.6 Avoid sudden stops or sharp turns by construction equipment during placement of sub-basematerials.

.7 Remove or replace geogrid improperly installed or damaged as directed by the Contract Administrator.

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4. MEASUREMENT AND PAYMENT

4.1 Geogrid

.1 Supply and installation of geogrid will be measured on an area basis and paid for at the Contract

Unit Price per square metre for “Supply and Install Geogrid”. The area to be paid for will be thetotal number of square metres of geogrid, supplied and installed in accordance with thisspecification, accepted and measured by the Contract Administrator.

.2 Only material placed within the designated sub-grade limits will be included in the payment for“Supply and Install Geogrid”.

.3 No measurement or payment will be made for geogrid removed and replaced due to improperinstallation or damaged materials.

.4 Adjacent roll joint fasteners will be included in payment for “Supply and Install Geogrid”.

.5 No measurement or payment will be made for the 900mm overlap described in this Specification.

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