15-division 2-section 02600 sewer rehabilitation-version 2.0

ADSSC/GSCW Division 02 Section 02600

Sewer Rehabilitation Rev: 02 Jan. 2011 of 34

ABU DHABI SEWERAGE SERVICES COMPANY

(ADSSC)

GENERAL SPECIFICATION FOR CIVIL WORKS

DIVISION 2 SITEWORK

SECTION 02600 SEWER REHABILITATION

General Specification for Civil Works Abu Dhabi Sewerage Services Company

(ADSSC)



DOCUMENT CONTROL SHEET

Revision No. Date Revision Description / Purpose of Issue

01 April 2008 First Issue.

02 Jan. 2011 ADSSC new logo

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TABLE OF CONTENTS

1 GENERAL ....................................................................................................... 4 1.1 SCOPE AND GENERAL REQUIREMENTS ......................................... 4 1.2 RELATED DOCUMENTS ..................................................................... 4 1.3 STANDARDS ....................................................................................... 5 1.3.1 ALTERNATIVE STANDARDS .............................................................. 6 1.4 SUBMITTALS ....................................................................................... 7 1.4.1 PRODUCTS AND MATERIALS APPROVAL ........................................ 7 1.4.2 METHOD STATEMENTS ..................................................................... 8 1.4.3 DRAWINGS ......................................................................................... 8 1.4.4 SAMPLES ............................................................................................ 9 1.5 QUALITY CONTROL............................................................................ 9 1.6 DELIVERY, STORAGE, AND HANDLING ............................................ 9 1.7 SAFETY ............................................................................................. 10

2 PRODUCTS ................................................................................................... 10 2.1 CURED IN PLACE PIPE LINER ......................................................... 10 2.2 DEFORMED AND REFORMED HDPE PIPE LINER .......................... 12 2.3 SPIRAL WOUND PIPE LINER WITH STAINLESS STEEL

REINFORCEMENT ............................................................................ 14 2.4 SLIPLINING ....................................................................................... 15 2.5 ANNULUS GROUT ............................................................................ 16 2.6 CHEMICAL SEALING MATERIALS ................................................... 16

3 EXECUTION .................................................................................................. 17 3.1 SEWER CLEANING ........................................................................... 17 3.1.1 GENERAL .......................................................................................... 17 3.1.2 CLEANING EQUIPMENT ................................................................... 18 3.2 CCTV SEWER INSPECTION AND SURVEY ..................................... 19 3.2.1 FOR SUBSIDIARY SEWER LINES .................................................... 19 3.2.2 FOR TRUNK SEWER LINES ............................................................. 19 3.3 SEWER FLOW CONTROL................................................................. 20 3.3.1 GENERAL .......................................................................................... 20 3.3.2 PIPE STOPPERS ............................................................................... 20 3.3.3 PUMPING AND BYPASSING OF FLOW ............................................ 21 3.3.4 TEMPORARY DIVERSION OF FLOW ............................................... 22 3.3.5 ENTRANCES TO PRIVATE PROPERTIES ....................................... 22 3.3.6 ODOUR CONTROL DURING PUMPING AND BYPASSING OR

DIVERTING OF FLOW ....................................................................... 22 3.3.7 GENERAL CLEANLINESS OF AREAS DURING SEWER CLEANING

........................................................................................................... 22 3.4 SEWER MANHOLE SEALING ........................................................... 23 3.5 SEWER PIPE JOINT SEALING ......................................................... 24 3.6 PREPARATION PRIOR TO LINER PIPE INSTALLATION ................. 25 3.7 CURED-IN-PLACE PIPE INSTALLATION .......................................... 26 3.8 DEFORMED AND REFORMED HDPE PIPE INSTALLATION ........... 28 3.9 SPIRAL WOUND PIPE INSTALLATION............................................. 29 3.10 SLIPLINING INSTALLATION ............................................................. 30 3.11 SEWER MANHOLE REHABILITATION ............................................. 31


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1 GENERAL

1.1 SCOPE AND GENERAL REQUIREMENTS

a) This section of the specification gives the requirements for the materials, equipment and methods to be adopted for the rehabilitation of sewers using lining techniques and the rehabilitation of manholes.

b) A wide variety of lining techniques have been developed world-wide. The

main Contractor is not constrained on the type of lining method he puts forward, but the Contractor will have to demonstrate, through previous project documentation, that the proposed method has a proven track record and that it is fully applicable to the conditions to be found in Abu Dhabi.

c) The acceptable systems for the rehabilitation of sewers are considered

to be:

i. Cured in place pipe liner. ii. Deformed and reformed high density polyethylene (HDPE) pipe

liner. iii. Spiral wound pipe liner with stainless steel reinforcement. Only for

sewers of 250mm diameter and greater. iv. Sliplining.

d) The Contractor shall design the liner to support all combinations of

imposed loads including earth, traffic, hydrostatic etc and have a minimum service life of 50 years. For the purposes of calculations it shall be assumed that the ground water table is at ground level. Host pipes shall be considered to be fully deteriorated. The liner shall have a minimum allowable long term stiffness of 2500N/m

2

and be designed to have a factor of safety of 2.

e) The normal requirement will be that the liner shall provide the least possible thickness or decrease in diameter to meet the requirements of this section and consequently shall be of the close fit type.

f) Liner shall be of a light colour to enhance Closed Circuit Television

(CCTV) clarity for inspection purposes.

g) Leak repair shall be carried out when required to create an environment to enable the rehabilitation works to be executed successfully. If the rehabilitation method adopted can be successfully implemented under wet conditions due to leaks, the Contractor is not obliged to repair the leaks.

1.2 RELATED DOCUMENTS

The following sections of the specification shall be read in conjunction with


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this section.

Section 01000-07 Submittals. Section 01000-08 Quality control. Section 01000-09 Materials and equipment. Section 02200 GRP pipelines. Materials, installation and testing. Section 02205 PVC-u pipelines. Materials, installation and testing. Section 02210 HDPE pipelines. Materials, installation and testing. Section 02700 Closed circuit television (CCTV) condition survey. Section 03600 Concrete protection and waterproofing.

1.3 STANDARDS

All activities relating to this section of the specification shall comply with the following or approved equal standards.

ASTM D543 Standard practices for evaluating the resistance of

plastics to chemical reagents. ASTM D638 Standard test method for tensile properties of plastics. ASTM D746 Standard test method for brittleness temperature of

plastics and elastomers by impact. ASTM D790 Standard test methods for flexural properties of

unreinforced and reinforced plastics and electrical insulating materials.

ASTM D991 Standard test method for rubber property. Volume resistivity of electrically conductive and antistatic products.

ASTM D1238 Standard test method for melt flow rates of thermoplastics by extrusion plastometer.

ASTM D1248 Standard specification for polyethylene plastics extrusion materials for wire and cable.

ASTM D1505 Standard test method for density of plastics by the density-gradient technique.

ASTM D1525 Standard test method for vicat softening temperature of plastics.

ASTM D1693 Standard test method for environmental stress cracking of ethylene plastics.

ASTM D1784 Standard specification for rigid poly (vinyl chloride) (PVC) compounds and chlorinated poly (vinyl chloride) (CPVC) compounds.

ASTM D2122 Standard test method for determining dimensions of thermosetting pipe and fittings.

ASTM D2152 Standard test method for adequacy of fusion of extruded poly (vinyl chloride) (PVC) pipe and moulded fittings by acetone Immersion.

ASTM D2240 Standard test method for rubber property -Durometer hardness.

ASTM D2412 Standard test method for determination of external loading characteristics of plastic pipe by parallelplate loading.


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ASTM D2837 Standard test method for obtaining hydrostatic design basis for thermoplastic pipe materials or pressure design basis for thermostatic pipe products.

ASTM D3350 Standard specification for polyethylene plastics pipe and fittings materials.

ASTM D4703 Standard practice for compression moulding thermoplastic materials into test specimens, plaques or sheets.

ASTM F585 Standard practice for insertion of flexible polyethylene pipe into existing sewers.

ASTM F714 Standard specification for polyethylene (PE) plastic pipe (SDR-PR) based on outside diameter.

ASTM F1216 Standard practice for rehabilitation of existing pipelines and conduits by the inversion and curing of a resin-impregnated tube.

ASTM F1248 Standard test method for determination of environmental stress crack resistance (ESCR) of polyethylene pipe.

ASTM F1533 Standard specification for deformed polyethylene (PE) liner.

ASTM F1606 Standard practice for rehabilitation of existing sewers and conduits with deformed polyethylene (PE) liner reinstated.

ASTM F1697 Standard specification for poly (vinyl chloride) (PVC) profile strip for machine spiral-wound liner pipe rehabilitation of existing sewers and conduits.

ASTM F1741 Standard practice for installation of machine spiral wound poly (vinyl chloride) (PVC) liner pipe for rehabilitation of existing sewers and conduits.

BS EN 1852-1 Plastics piping systems for non-pressure underground drainage and sewerage -Polypropylene (PP).

ISO 9000 Quality management systems. 1.3.1 ALTERNATIVE STANDARDS

For deformed and reformed HDPE liner the following alternative standards may be adopted by the Contractor.

BS EN 13566-1 Plastics piping systems for renovation of underground

non-pressure drainage and sewerage networks. Part 1 General.

BS EN 13566-3 Plastics piping systems for renovation of underground non-pressure drainage and sewerage networks. Part 3 Lining with close fit pipes.

BS EN 13689 Guidance on the classification and design of plastics piping systems used for renovation.

a) However the Contractor must demonstrate that the materials, general

characteristics, material characteristics, geometric characteristics,


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mechanical characteristics, physical characteristics, jointing, marking, sampling and installation of the liner supplied to the above alternative standards, amended as necessary, meet or exceed all of the requirements of this section of the specification. Any amendments required to the above alternative standards to satisfy the requirements of this specification shall be clearly identified by the Contractor, for example longitudinal tensile stress at yield point shall be 20N/mm² and minimum stiffness shall be 2500N/m². The amendments shall not necessarily be limited to these examples.

1.4 SUBMITTALS

1.4.1 PRODUCTS AND MATERIALS APPROVAL

In order to verify compliance with the specification the Contractor shall submit information for all products and materials used in the Works to the Engineer for approval sufficiently in advance of their use in accordance with the Contract programme allowing for ordering and approval times. Reference shall also be made to Section 01000-09 of the specification on products and materials approval. Information to be submitted shall comprise but not necessarily be limited to:

a) Liner

i. Manufacturers name. ii. Suppliers name. iii. Installers name. (Sub contractor) iv. Product name (if applicable). v. Product description. vi. Manufacturers technical data. vii. Test results or certificates. viii. Checked and approved liner pipe thickness design and stiffness

calculations. ix. Storage instructions. x. Installation instructions. xi. Installation records in the same project area.

b) Proposed grout mixture, where applicable.

c) Manhole and joint sealing materials and manhole rehabilitation materials.

i. Manufacturers name. ii. Suppliers name. iii. Installers name. (Sub contractor) iv. Product name (if applicable). v. Product description. vi. Manufacturers technical data. vii. Test results or certificates. viii. Storage instructions. ix. Application instructions.


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1.4.2 METHOD STATEMENTS

a) The Contractor shall submit method statements to the Engineer for approval 4 weeks in advance of commencing the site activity in accordance with Section 01000-07 of the specification. These shall comprise but not necessarily be limited to:

b) Sewage bypass pumping and/or diversion plan which shall include an

emergency response plan to be followed in the event of a failure of the bypass pumping and/or diversion plan.

c) Detailed construction plan including:

i. Equipment set-up and locations of proposed access points. ii. Anticipated cut off periods for services. iii. Procedures for verification of active service connections. iv. Procedures for notifying affected residences and businesses. v. Procedures for complying with traffic control. vi. Procedures to be adopted to obtain permits to work from the

ADSSC Operation and Maintenance Section. vii. Safety procedures in particular working with scaffolding, entering

confined spaces and operations with hot media. viii. Sewer cleaning procedures. ix. Liner installation procedures. x. Procedures for sealing annular space between liner pipe and host

pipe where applicable. xi. Methods of sealing any annular space between liner pipe and host

pipe at manholes. xii. Procedures for manhole liner to pipe liner joint sealing. xiii. Procedures for manhole rehabilitation. xiv. Procedure for any required modifications either temporary or

permanent to existing manholes such as widening of access opening, removal of cover slabs, removal of intermediate landings and ladders, and removal of manhole benching etc.

1.4.3 DRAWINGS

a) The Contractor shall submit drawings to the Engineer for approval in advance of commencing the site activity in accordance with Section 01000-07 of the specification. These shall comprise but not necessarily be limited to:

i. Liner insertion locations. ii. Sewage bypass pumping and/or diversion locations. iii. Liner end sealing at manholes. iv. GRP lamination to manhole wall and benching liners if applicable. v. Any required modification to existing manholes.


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1.4.4 SAMPLES

a) Representative samples, as agreed with the Engineer, must be submitted for at least the following items at the same time as the particulars are submitted.

i. Proposed liner system. ii. Liner to host pipe sealing materials. iii. Manhole rehabilitation materials. iv. Manhole liner to pipe liner sealing materials.

1.5 QUALITY CONTROL

a) Prior to dispatch of any product and/or material from source the Contractor shall notify the Engineer in writing in sufficient time to allow the Engineer the opportunity to inspect and test the product and/or material prior to delivery in accordance with Section 01000-08 of the specification.

b) Products and materials shall be from a manufacturer/supplier who

operates a quality system which is registered to ISO 9000 series or approved equal.

c) To allow the Engineer to inspect the Works the Contractor shall give the

Engineer a minimum of 24 hours notice of carrying out the following activities on site.

i. Sewer cleaning. ii. CCTV survey. iii. Sewage bypass pumping and/or diversion. iv. Liner installation. v. Manhole rehabilitation.

d) The finished liner shall be continuous over the entire length of an

insertion run between two manholes or access points and shall be free from visual defects.

1.6 DELIVERY, STORAGE, AND HANDLING

a) Delivery, storage and handling of products and materials shall be in accordance with the manufacturer’s recommendations, Section 01000-09 of the specification and the following provisions.

b) Delivery storage and handling shall at all times be performed in a

manner to avoid product damage.

c) The liner shall not come in contact with any sharp projections that may cause damage during transportation loading and unloading. Cover liner during transportation.


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d) Store materials on a flat level area and raised above the ground on timber bearers.

e) Store materials under opaque cover and out of direct sunlight at all times.

Maintain a free flow of air around the materials at all times.

f) The Contractor shall visually inspect all products upon delivery to site and report any damage to the Engineer.

i. Any products damaged during delivery, storage and handling shall

be marked by the Contractor and set aside. ii. Proposals for repair of any damaged products shall be submitted in

writing to the Engineer for approval. iii. Any damaged products deemed unsuitable for repair by the

Engineer shall be removed from site and replaced.

1.7 SAFETY

a) The Contractor shall be solely responsible for safety during the performance of all work. The Contractor shall not enter into any sewer where hazardous conditions may exist until such time as the source of these conditions is eliminated by the Contractor. Contractor shall perform all work in accordance with the latest applicable confined space entry regulations. Contractor shall coordinate his work with local, fire police and emergency rescue units.

b) The Contractor shall be responsible for any damage to public or private

property resulting from his work and shall repair or make whole such damage at no cost to ADSSC.

2 PRODUCTS

2.1 CURED IN PLACE PIPE LINER

a) The liner material shall be designed for use in gravity sewers and shall be in strict conformance with all applicable sections of ASTM F1216.

b) The felt liner tube shall be a thermoplastic polyester tube consisting of

one or more layers of flexible needled felt or an equivalent woven and/or non/woven material capable of carrying resin, and with sufficient needling and crosslapping and strength to withstand the installation pressures and curing temperatures.

c) The felt tube shall be compatible with the resin and catalyst systems to

be utilised.

d) The finished liner shall consist of a felt layer (or layers) impregnated with a thermosetting resin and fabricated to fit tight against the host pipe. An allowance shall be made for circumferential stretching during installation where applicable.


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e) The resin used shall be a general purpose, unsaturated, thermosetting,

vinylester resin able to cure in the presence or absence of water and a catalyst system compatible with the insertion process.

f) Each felt liner tube shall be clearly marked by the manufacturer with the

following information:

i. Manufacturer’s name. ii. Manufacturer’s production code from which plant location, machine

and date of manufacture can be identified. iii. The project or contract number.

g) The lining technique shall comprise using a suitable preliner to prevent

loss of resin.

h) The liner shall be fabricated from materials which when cured, will be resistant to internal exposure to sewage, sewage gases and reagents listed in Table 2.1.1 below, when tested in accordance with the provisions of ASTM D543, to a temperature of 40°C.

Table 2.1.1 – List of Reagents

Reagent Concentration

Potable water (ph 5,5 – 9.0)

100%

Sea water

100%

Nitric acid 10%

Phosphoric acid

5%

Sulphuric acid 10%

Vegetable oil 100%

Detergent 0.1%

Soap 0.1%

i) The liner shall meet, or exceed, the physical properties given in Table

2.1.2 below.

j) At the time of installation the liner shall be free of all visible tears, holes, cuts, foreign materials and other defects.


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Table 2.1.2 – Cured in Place Liner Properties

Property Test Method Value

Flexural strength ASTM D790 31N/mm2

Short term flexural modulus

ASTM D790 1724N/mm

Long term flexural modulus

2

ASTM D790 862N/mm2

Tensile strength

ASTM D638 21N/mm2

2.2 DEFORMED AND REFORMED HDPE PIPE LINER

a) The HDPE liner material shall be designed for use in gravity sewers and shall be in strict conformance with all applicable sections of ASTM F1533.

b) The liner shall be made from High Density Polyethylene resins

complying with ASTM D1248, Type III, Grade P34 and Cell Classification PE 345434C, D or E per ASTM D3350. The Contractor shall submit to the Engineer for approval certified test results from the liner pipe manufacturer to verify that the resin material used for extrusions of the liner meets the specified requirements, including the quality control records during the liner extrusion process.

c) At the time of manufacture, each lot of liner shall be inspected for

defects with samples being taken in accordance with ASTM D4703 and tested in accordance with ASTM D1693, ASTM D2837 and ASTM F714.

d) For testing purposes a production lot shall consist of all liner having the

same marking number. It shall include all items produced during any given work shift and must be identified accordingly to differentiate it from previous or following production.

e) Each deformed liner coil in compliance with ASTM F1533 shall be clearly

marked by the manufacturer with the following information:

i. ASTM F1533 designation. ii. Nominal outside diameter. iii. SDR. iv. Approximate coil length. v. Standard material designation code. vi. Manufacturer’s name. vii. Manufacturer’s production code from which plant location, machine

and date of manufacture can be identified. viii. The project or contract number.


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f) Liner minimum wall thickness shall be determined by strength and minimum stiffness requirements of Clause 1.1D.

g) The liner shall be fabricated from materials which will be resistant to

internal exposure to sewage, sewage gases and reagents listed in Table 1 above, when tested in accordance with the provisions of ASTM D543, to a temperature of 40°C.

h) The HDPE material used in the production of the liner shall meet, or

exceed, the physical properties given in Table 2.2.1 below.

Table 2.2.1 – Deformed and Reformed HDPE Liner Properties


Density ASTM D1505 >940kg/m

Flow rate

3

ASTM D1238 >8.0g/10min

Tensile strength @ yield ASTM D638 >20N/mm

Ultimate elongation

2

ASTM D638 >600%

Flexural modulus ASTM D790 >1000N/mm

Environmental stress crack

2

resistance F0 ASTM D1693 , hours condition C 10,000hrs Compressed ring ESCR F0 ASTM F1248 10,000hrs

Brittleness temperature ASTM D746 <-1170

Vicat softening temperature

C

ASTM D1525 >1250

Hardness, Shore D

C

ASTM D2240 >50 Volume resistivity ASTM D991 >1015

Ohm-cm

Thermal expansion - <0.20mm/m/0

C

i) At the time of installation the liner shall be homogeneous throughout, uniform in colour, free of cracks, holes, foreign materials, blisters and deleterious faults.


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2.3 SPIRAL WOUND PIPE LINER WITH STAINLESS STEEL REINFORCEMENT

a) The physical properties of the PVC-u material used in the production of the liner shall conform to the cell classifications 12344 or 13354 as defined by ASTM D1784.

b) The PVC-u base material for the liner shall consist of a profile walled

strip, extruded from a thermoplastic material or other material approved by the Engineer in accordance with ASTM F1697.

c) Each liner shall be clearly marked by the manufacturer with the following

information:

i. Manufacturer’s name. ii. Manufacturer’s production code from which plant location, machine

and date of manufacture can be identified. iii. The project or contract number.

d) All materials used in the finished pipe shall be resistant to internal

exposure to sewage, sewage gases and reagents listed in Table 1 above, when tested in accordance with the provisions of ASTM D543, to a temperature of 40°C.

e) The liner shall meet, or exceed, the physical properties given in Table

2.3.1 below.

Table 2.3.1 - Spiral Wound Liner Properties


Short term flexural modulus ASTM D790 >2400N/mm

Long term flexural modulus

2

ASTM D790 >800N/mm

Short term tensile strength

2

ASTM D638 41N/mm

Long term tensile strength

2

ASTM D638 20N/mm

Heat distortion temperature

2

- 70o

Specific density

C

ASTM D1505 1.4

Allowable long term strain - 2%

Hardness - Shore D ASTM D2240 75

f) At the time of installation the liner shall be homogenous throughout,

uniform in colour, free of cracks, holes, foreign materials, blisters and deleterious faults.


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g) The strength of the liner shall be enhanced by the provision of stainless

steel reinforcement wound into the liner at the time of installation.

h) The steel reinforcement shall be stainless steel type 316L. The steel shall meet or exceed the physical properties given in Table 2.3.2 below.

Table 2.3.2 – Physical Properties of Reinforcement

Property Value

Tensile strength > 250N/mm

Modulus of elasticity

2

190-200 kN/mm

Coefficient of thermal expansion

2

9 X 10-6 0

C

2.4 SLIPLINING

a) Sliplining shall be carried out using High Density Polyethylene (HDPE) to the material requirements and standards as given in Section 02210 of the specification, or Polypropylene (PP) to BS EN 1852-1.

b) All liner pipe shall be provided with joints designed so that neither the

outside diameter of the pipe is increased nor the internal diameter of the pipe is decreased at the joint.

c) Ensure that all pipes including cut lengths and all fittings before dispatch

from the pipe manufacturer’s works are indelibly marked as follows:

i. The manufacturer’s name, initials, or identification mark. ii. The nominal internal diameter in mm. iii. The length in m. iv. Mark the classification i.e. pressure rating, stiffness. v. The date of manufacture and batch number. vi. A stamp to show that they meet the required inspection

requirements and hydraulic tests at the point of manufacture. vii. Stencil in legible letters the pipe identification number on the inside

and outside at each end. Ensure that the same number appears on all record sheets and documents relating to the manufacture delivery and testing of that pipe.

viii. The manufacturing standard. ix. The project or contract number.


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2.5 ANNULUS GROUT

Low strength grout for filling the annular space between the host pipe and the liner, where applicable, shall be a cementitious mixture incorporating suitable admixtures as approved by the Engineer and shall have a minimum compressive strength of 12N/mm².

2.6 CHEMICAL SEALING MATERIALS

a) Chemical resin for sealing pipe joints and manholes shall be a hydrophilic polyurethane compound suitable for injection.

b) The material must be “salt-water” grade able to react with saline ground

water to form a flexible seal.

c) In every case, mixing and handling of chemical sealing materials shall be in strict accordance with the manufacturer’s recommendations.

d) All chemical sealing materials used in the performance of the work

specified must have the following properties and characteristics:

i. While being injected, the chemical sealant must be able to react/perform in the presence of saline groundwater.

ii. The cured material must withstand submergence in water without degradation.

iii. The seal formed must prevent the infiltration of water through the sewer pipe joint.

iv. The sealant material, after curing, must be flexible. v. In place, the sealant formation should be able to withstand wet/dry

cycles without adversely affecting the seal. vi. The sealant formation must not be biodegradable. vii. The cured sealant should be chemically stable and resistant to the

concentrations of acids, alkalis, and organics found in normal sewage in Abu Dhabi.

viii. Packaging of component material must be compatible with field storage and handling requirements. Packaging must provide for worker safety and minimise spillage during handling.

ix. Mixing of the component materials must be compatible with field operations and not require precise measurements of the ingredients by field personnel.

x. Clean up must be done without excessive use of flammable or hazardous chemicals.

xi. Residual sealing materials must be easily removable from the sewer line to prevent reduction or blockage of the sewage flow.


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3 EXECUTION

3.1 SEWER CLEANING

3.1.1 GENERAL

a) The Contractor will be provided with sewer lines that have been periodically cleaned by the ADSSC Operation and Maintenance Section or a nominated Contractor. Any additional cleaning required to carry out the Works specified herein will be the responsibility of the Contractor.

b) The scope of operations for sewer and manhole cleaning is intended to

include, but not be limited to the following elements of work:

i. Location of manholes using suitable detection techniques and removal of overburden.

ii. Cleaning of manholes with water jetting, and/or wire brushing or other approved means.

iii. Removal of any sand, debris etc. from manhole bases and benching.

iv. Stanking off flows and pumping where necessary. v. Cleaning of sewers using hydraulically propelled or mechanically

powered equipment or water jetting. vi. Removal of all sand and debris etc. jetted or dredged from the

sewers and disposal of same to an approved tip. vii. Controlling of odour and nuisance arising out of cleaning, flow

diversion or over pumping operations.

c) The designated sewer manhole sections shall be cleaned using hydraulically propelled, high-velocity jet, or mechanically powered equipment. The equipment and methods selected shall be satisfactory to the Engineer. The equipment shall be capable of removing dirt, grease, rocks, sand, and other materials and obstructions from the sewer lines and manholes. If cleaning of an entire section cannot be successfully performed from one manhole, the equipment shall be set up on the other manhole and cleaning again attempted. If, again, successful cleaning cannot be performed or the equipment fails to traverse the entire manhole section, it will be assumed that a major blockage exists and the cleaning effort shall be abandoned.

d) If the Contractor’s cleaning equipment becomes lodged in a sewer it

shall be removed by the Contractor at his own expense. This shall include excavation, repair of sewer, backfill and surface restoration.

e) All sludge, dirt, sand, rocks, grease, and other solid or semi-solid

material resulting from the cleaning operation shall be removed at the downstream manhole of the section being cleaned. Passing material from manhole section to manhole section, which could cause line stoppages, accumulations of sand in wet wells, or damage pumping equipment, shall not be permitted.


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f) All solids or semi-solids resulting from the cleaning operations shall be

removed from the site and disposed off site. All materials shall be removed from the site no less often than at the end of each workday. Under no circumstances will the Contractor be allowed to accumulate debris, etc., on the site of work beyond the stated time, except in totally enclosed containers and as approved by the Engineer.

g) Acceptance of sewer line cleaning shall be made upon the successful

completion of the television inspection and shall be to the satisfaction of the Engineer. If TV inspection shows the cleaning to be unsatisfactory, the Contractor shall be required to reclean and reinspect the sewer line until the cleaning is shown to be satisfactory.

3.1.2 CLEANING EQUIPMENT

a) Hydraulically propelled equipment shall be of a movable dam type and be constructed in such a way that a portion of the dam may be collapsed at any time during the cleaning operation to protect against flooding of the sewer. The movable dam shall be equal in diameter to the pipe being cleaned and shall provide a flexible scraper around the outer periphery to ensure removal of grease. Sewer cleaning balls or other equipment which cannot be collapsed shall not be used.

b) High-velocity jet (Hydrocleanlng) equipment shall be constructed for

ease and safety of operation. The equipment shall have a selection of two or more high velocity nozzles. The nozzles shall be capable of producing a scouring action from 15 to 45 degrees in all size lines designated to be cleaned. Equipment shall also include a high-velocity gun for washing and scouring manhole walls and floor. The gun shall be capable of producing flows from a fine spray to a solid stream. The equipment shall carry its own water tank, auxiliary engines, pumps and hydraulically driven hose reel.

c) Mechanically powered equipment of a power rodding machine type shall

be either a sectional or continuous rod type capable of holding a minimum of 200 m of rod. The rod shall be specifically heat-treated steel. To ensure safe operation, the machine shall be fully enclosed and have an automatic safety clutch or relief valve. Buckets, scrapers, scooters, porcupines, brushes and other mechanical equipment may also be utilised.

d) All equipment and devices shall be operated by experienced personnel

so that sewer lines are not damaged in the process of cleaning. When hydraulically propelled tools (which depend upon water pressure to provide their cleaning force) or tools which retard the flow in the sewer line are used, precautions shall be taken to ensure that the water pressure created does not damage or cause flooding of property being served by the sewer. When possible, the flow of sewage in the sewer shall be utilised to provide the necessary pressure for hydraulic cleaning


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devices. When additional water from hydrants is necessary to avoid delay in normal work procedures, the water shall be conserved and not used unnecessarily.

e) Roots shall be removed in the designated sections where root intrusion

is a problem. Special attention should be used during the cleaning operation to assure almost complete removal of roots from the joints. Procedures may include the use of mechanical equipment such as rodding machines, bucket machines and winches using root cutters and porcupines, and equipment such as high-velocity jet cleaners.

3.2 CCTV SEWER INSPECTION AND SURVEY

a) CCTV sewer inspection and survey shall be performed after suitable cleaning of the pipeline as described above in clause 3.1 and shall be carried out to the requirements of Section 02700 of the specification.

b) Scope of operations for CCTV inspection and survey shall include, but

not be limited to the following elements of work: 3.2.1 FOR SUBSIDIARY SEWER LINES

a) After cleaning, the sewer lines shall be visually inspected by means of CCTV.

b) Following rehabilitation works, if required, the sewer lines shall be

visually inspected by means of CCTV.

c) The inspection will be done one sewer length at a time with the flow in the section being inspected suitably controlled as detailed in section 3.3 below.

d) Up to 10% of the rehabilitated sewers shall be CCTV surveyed at the

end of the maintenance period in order to assess the general condition of the rehabilitated sewers. This survey shall demonstrate to the Engineers satisfaction the successfulness of the rehabilitation works. Any defects shall be repaired by the Contractor at no cost to ADSSC and a further 10% of the rehabilitated sewers shall be CCTV surveyed with the process being repeated until no defects are found in the 10% sample of rehabilitated sewers.

3.2.2 FOR TRUNK SEWER LINES

a) After cleaning CCTV and deflection measurement of the sewer lines shall be carried out.

b) Following rehabilitation works, if required, CCTV and deflection

measurement of the sewer lines shall be carried out.

c) The inspection will be done one sewer length at a time with the flow in the section being inspected suitably controlled as detailed in section 3.3


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below.

d) Deflection measurement readings for flexible pipe sewer lines must be taken vertically and horizontally at the same location.

e) Up to 10% of the rehabilitated sewers shall be CCTV surveyed at the

end of the maintenance period in order to assess the general condition of the rehabilitated sewers. This survey shall demonstrate to the Engineers satisfaction the successfulness of the rehabilitation works. Any defects shall be repaired by the Contractor at no cost to ADSSC and a further 10% of the rehabilitated sewers shall be CCTV surveyed with the process being repeated until no defects are found in the 10% survey sample of rehabilitated sewers.

3.3 SEWER FLOW CONTROL

3.3.1 GENERAL

a) The Contractor should be aware of social and climatic conditions pertaining to Abu Dhabi particularly in dealing with sewage and consequential pumping and bypassing or diverting of sewage flows. All works shall be carried out in such manner as to cause minimum disruption, noise or any nuisance to the public.

b) Manholes and sewers being worked on shall be completely isolated and

bypassed such that they do not contain any sewage. This shall be achieved by plugging, pumping and bypassing or diverting the flow.

c) When flow in a sewer line is plugged, pumped and bypassed or diverted

sufficient precautions must be taken to protect the sewer lines from damage that might result from sewer surcharging. Further, precautions must be taken to ensure that sewer flow control operations do not cause flooding or damage to public or private property being served by the sewers involved.

3.3.2 PIPE STOPPERS

a) The flow shall be stoppered off using an approved type of pipe stopper. Stoppers shall be suitable for the sizes and classes of pipe in which they are used and must not cause damage to existing pipes. Stoppers must be able to withstand the maximum possible differential head at each location and shall be fully restrained in accordance with the manufacturers recommendations.

b) The Contractor shall be solely responsible for maintaining such stoppers

in good working condition and for the consequences of any failure thereof.

c) Where a section of the sewerage system is isolated for work involving

man-entry to the isolated area, a minimum of two stoppers shall be used at each boundary location isolating the area from the main sewer and


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subsidiary sewers. At least one of these stoppers at each location should be of an approved pneumatic type.

3.3.3 PUMPING AND BYPASSING OF FLOW

a) Pumping shall be carried out using suitable mobile pumpsets to the approval of the Engineer.

b) The pumps shall be controlled by suitable level controls installed to

operate at levels to be approved by the Engineer and shall be capable of dealing with the flow in the sewer and any material likely to be transported in it without being blocked.

c) The Contractor must provide enough temporary pumps of sufficient

pumping capacity or where approved, a temporary sump to avoid surcharging upstream sewers.

d) Constant full time attendance shall be provided by the Contractor at

each pumping location such that in the event of mechanical breakdown, flooding or blockage, immediate assistance will be summoned.

e) Discharge of pumped sewage shall be made to a manhole downstream

of the sewer length being surveyed. The open end of the pump discharge pipe shall be laid so as to minimise turbulence of the pumped flow.

f) The pump discharge pipe shall be of suitable armoured material which in

all locations subject to traffic flow shall be suitably protected with steel preformed plates bridging the pipe or by other approved means. Such protection shall be adequate to allow passage of vehicular traffic over the pipe without undue inconvenience.

g) The Contractor shall restrict the sewage residence time in bypass hoses

to not more than 10 minutes or as approved by the Engineer and shall provide adequate standby facilities of both suitable pumps and generators for use at short notice in the event of failure of either piece of equipment.

h) For main streets, non disruptive road crossings may be required and the

Contractor shall include the cost of constructing such crossings in his rates of rehabilitation works. It is possible that ducts or storm water sewers are available in the vicinity of the diversion which can be used by the Contractor to install his temporary bypass pipes after taking approval of the relevant authority.

i) On completion of pumping, the Contractor shall carry out sewer cleaning

by jetting, flushing or any other means required to return the sewer surcharged during pumping operations to a serviceable condition to the satisfaction of the Engineer.


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3.3.4 TEMPORARY DIVERSION OF FLOW

a) If the Contractor considers it necessary for temporary diversion of sewers to be carried out to enable him to execute his work then he should notify the Engineer accordingly and submit his proposals for implementation of such diversion.

b) The Contractor shall give full details of pipe diameter, route, levels etc. In

such proposals, and subject to the Engineer’s approval, the Contractor shall be solely responsible for obtaining all other permissions and approvals relevant to the execution of such temporary works. On completion of temporary diversionary works the relevant pipework shall be removed or be adequately sealed and inlet and outlet manholes returned to a condition suitable for their subsequent re-use, all to the approval of the Engineer. All diversionary work shall be subject to the requirements of the Contract as if they formed part of the Permanent Works.

3.3.5 ENTRANCES TO PRIVATE PROPERTIES

a) No pumps or equipment shall be fixed in front of private properties unless it is unavoidable and this shall be with the approval of the Engineer. When it is essential to close any access, the Contractor shall provide suitable alternative access at no extra cost to ADSSC. Vehicle access for emergency services shall be available at all times.

3.3.6 ODOUR CONTROL DURING PUMPING AND BYPASSING OR

DIVERTING OF FLOW

a) The Contractor shall take necessary arrangements for controlling odour and prevent any nuisance and inconvenience to the local residents and the public generally as a result of pumping and bypassing or diverting of flow.

b) The Contractor shall include in his proposed method the equipment and

chemicals he is proposing to use to contain the odour release for approval by the Engineer.

c) The Contractor shall install temporary chemical dosing system to contain

the odour release if other measures fail.

d) For odour control, the measurement of hydrogen sulphide shall not be more than 1 ppm measured at a distance of 5m from the point of discharge to the adjacent property.

3.3.7 GENERAL CLEANLINESS OF AREAS DURING SEWER CLEANING

a) The Contractor shall ensure that while removing manhole covers and subsequent cleaning operations there is no spillage of sewage, debris and other particles onto the streets, near manholes and other areas causing nuisance to the local residents and the public.


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b) The Contractor shall clear all spillages, wash and clean affected

surfaces with water as and when spillage occurs. 3.4 SEWER MANHOLE SEALING

a) It is the intent to provide for the elimination of extraneous water leakage into manholes that are otherwise structurally sound. All manhole sealing shall be done during high groundwater conditions, unless the points of leakage have been previously identified.

b) The basic equipment shall consist of chemical pumps, chemical

containers, injection packers, hoses, valves, and all necessary equipment and tools required to seal manholes. The chemical injection pumps shall be equipped with pressure meters that will provide for monitoring pressure during the injection of the chemical sealant. When necessary, fluid bypass lines equipped with pressure-regulated bypass valves will be incorporated into the pumping system.

c) At each point of leakage within the manhole structure the existing GRP

lining, if applicable, shall be removed over a sufficient area to expose the leakage point so that a hole could be carefully drilled from within the manhole and shall extend through the entire manhole wall. In cases where there are multiple leaks around the circumference of the manhole, fewer holes may be drilled providing all leakage is stopped from these holes. Into the previously drilled holes, chemical sealant injection devices shall be placed In such a way that they will provide a watertight seal between the holes and the Injection device. A hose, or hoses, shall be attached to the injection device from an injection pump. Chemical sealing materials as specified shall then be pumped through the hose until material refusal is recorded on the pressure gauge mounted on the pumping unit or a predetermined quantity of sealant has been injected. Care shall be taken during the pumping operation to ensure that excessive pressures do not develop and cause damage to the manhole structure. Upon completion of the injection, the injection packers shall be removed and the remaining holes filled with mortar and troweled flush with the surface of the manhole walls or other surfaces. The mortar used shall be of the fast set type with “nonshrinking” characteristics.

d) After the manhole sealing operation has been completed, the manhole

shall be visually inspected for the elimination of excessive infiltration by the Contractor in the presence of the Engineer. In addition, the Contractor will be required within one year to visually inspect the manholes that were sealed. Any sealing work that has become defective shall be resealed by the Contractor at no additional expense to ADSSC.

e) All GRP lining removed or damaged as a result of the sealing works

shall receive an insitu GRP lamination to the requirements of Section 03600 of the specification. In places where other liner materials are encountered proposals for the repair of the liner shall be submitted to the Engineer for his approval.


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f) Where the points of leakage are extensive but the manhole is structurally

sound the leaks shall be repaired and an insitu GRP lamination to the requirements of Section 03600 of the specification shall be applied over the entire surface area of the existing GRP liner to the manhole.

g) Every precaution must be taken to prevent the formation of blisters in the

existing GRP lining due to the change in environmental conditions within the manhole during the repair process. If blisters do occur then the blistered areas must be cut out and the areas repaired by applying an insitu GRP lamination to the cut out area. Where the entire surface area is to receive an insitu GRP lamination this repair work shall be carried out prior to the application of the overall lamination. The Contractor shall also review his repair procedure and submit alternative proposals with a view to preventing the formation of blisters for the Engineers approval.

3.5 SEWER PIPE JOINT SEALING

a) Sewer pipe joints shall be sealed utilising the internal joint sealing method. It is realised that this method may only be used on sewer pipe sections in sound physical condition. Longitudinally cracked or broken pipe will not be sealed. When bell cracks or chips are evident from pipe section offset, sealing may be undertaken where the offset is small enough to allow proper seating of the sealing packer on both sides of the joint to be sealed.

b) The basic equipment shall consist of a closed-circuit television system,

necessary chemical sealant containers, pumps, regulators, valves, hoses, etc., and joint sealing packers for the various sizes of sewer pipes. The packer shall be cylindrical and have a diameter less than the pipe size and have cables attached at each end to pull it through the line. The packer device shall be constructed in a manner to allow a restricted amount of sewage to flow. Generally, the equipment shall be capable of performing the specified operations in lines where flows do not exceed the maximum line flows for joint testing/sealing.

c) Joint sealing shall be accomplished by forcing chemical sealing

materials into or through faulty joints by a system of pumps, hoses, and sealing packers. Jetting or driving pipes from the surface that could damage or cause undermining of the pipelines shall not be allowed. Uncovering the pipe by excavation shall not be allowed. The packer shall be positioned over the faulty joint by means of a measuring device and the closed-circuit television camera in the line. It is important that the procedure used by the Contractor for positioning the packer is accurate to avoid overpulllng the packer and thus not effectively sealing the intended joint. The packer ends shall be expanded using controlled pressure. The expanded ends shall seal against the inside periphery of the pipe to form a void area at the faulty joint, now completely isolated from the remainder of the pipeline. Into this isolated area, sealant materials shall be pumped through the hose system at controlled pressures which are in excess of groundwater pressures. The pumping


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unit, metering equipment and the packer device shall be designed so that proportions and quantities of materials can be regulated in accordance with the type and size of the leak being sealed.

d) Upon completing the sealing of each individual joint, the packer shall be

deflated until the void pressure meter reads zero pressure, then reinflated and the joint retested. Should the void pressure meter not read zero, the Contractor shall clean his equipment of residual grout material or make the necessary equipment repairs/adjustments to produce accurate void pressure readings. Joints that fail to meet the specified test criteria shall be resealed and retested until satisfactory results are obtained.

e) Residual sealing materials that extend into the pipe, reduce the pipe

diameter, or restrict the flow shall be removed from the joint. The sealed joints shall be left reasonably “flush” with the existing pipe surface. If excessive residual sealing materials accumulate in the line the manhole section shall be cleaned to remove the residual materials.

f) Complete records shall be kept of joint sealing performed in each

manhole section. The records shall identify the manhole section in which the sealing was done, the location of each joint sealed, and the joint sealing verification results.

3.6 PREPARATION PRIOR TO LINER PIPE INSTALLATION

a) Sewer sections to be lined shall be kept free of flows by one of the methods identified in Clause 3.03 above.

b) Prior to insertion of a sewer lining the Contractor shall ensure that the

sewer is clean and in a condition acceptable for the lining process to proceed. A CCTV inspection shall be used following such cleaning to ensure that sewer lengths are suitable for the lining process to be carried out. CCTV inspection shall be carried out in accordance with Section 02700 of the specification.

c) Where infiltration of groundwater at pipe joints, cracks, collapsed pipe

and other defects have been identified these shall be repaired by methods approved by the Engineer prior to the installation of any lining.

d) No lining work shall be permitted until the prepared sewer has been

inspected and approved by the Engineer.

e) Where it is necessary to carry out any modification to existing manholes to enable manhole and/or sewer cleansing, CCTV survey or sewer rehabilitation, the Contractor shall carry out any such modification to the Engineer’s approval. Following completion of the works in a manhole, the Contractor shall return the manhole to its original or better condition to the approval of the Engineer including reinstatement to surfaces disturbed as a result of manhole modification/sewer rehabilitation. Modification to manhole may include removal of manhole cover slab,


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intermediate landing slabs, platforms and manhole benching. Intermediate landing slabs/platforms that have been removed may not necessarily have to be reinstated, at the Engineer’s discretion, provided the GRP wall liner is extended to cover the exposed area due to slab removal and welded to the existing liner, and the GRP ladder is adjusted and re-installed as a continuous ladder throughout the manhole height. Unless specifically itemised and listed in the Bill Of Quantities, modifications to manholes which may be necessary to carry out the sewer rehabilitation and associated works shall be deemed to be included in the sewer rehabilitation rates.

3.7 CURED-IN-PLACE PIPE INSTALLATION

a) The Contractor shall retain the services of a licensed installer of the manufacturer of the cured in place liner pipe sewer rehabilitation system to assist the Contractor during preparation and installation of the system to certify that the work has been performed in accordance with the manufacturer’s recommendations.

b) The following procedures shall serve as a general installation guide only.

The Contractor shall obtain detailed installation instructions and procedures from the manufacturer for the actual installation of the cured in place liner system. The requirements of ASTM F1216 shall also be satisfied.

i. The section of pipeline to be lined shall have been cleaned,

surveyed and repaired to the requirements of this section of the standard specification prior to liner installation.

ii. The flexible felt liner tube shall be fabricated to a size that when installed will neatly fit the internal circumference of the required sewer. Allowance shall be made for circumferential stretching during insertion. The minimum length shall be that deemed necessary by the Contractor to effectively span the distance from the inlet to the outlet of the respective manholes unless otherwise specified. The Contractor shall verify the lengths in the field before impregnation. Individual installation runs can be made over one or more manhole sections as determined in the field by the Contractor and approved by the Engineer.

iii. Prior to insertion the Contractor shall have provided data on the maximum allowable stresses and elongation of the tube. The exterior of the manufactured tube shall be marked along its length at regular intervals not to exceed 1.5m. These marks shall be used as a gauge to measure elongation during insertion. Should the elongation at any time exceed the allowable values the liner shall be rejected.

iv. The Contractor shall designate a location or locations where the liner tube will be vacuum impregnated prior to installation. The Contractor shall allow the Engineer to inspect the materials and impregnation procedure. The impregnated liner tube shall be inserted through an existing manhole or other approved access by means of an inversion process, winch in place or other approved


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technique. The liner shall be maintained under a suitable internal pressure using water or air for example to push the liner against the host pipe walls. The liner shall then be cured by using the appropriate catalyst, warm water, steam, ultra violet light etc. to initiate the chemical reaction that hardens the resin and tube material. Gauges shall be located between the impregnated liner and the host pipe invert and as recommended by the manufacturer to monitor temperatures during the curing period.

v. Initial cure shall be deemed to be completed when inspection of the exposed portions of cured pipe appear to be hard and sound and the remote temperature sensor indicates that the temperature is of a magnitude to realise an exotherm. The cure period shall be of a duration recommended by the resin manufacturer.

vi. The Contractor shall cool the hardened liner pipe to a temperature below 38o

vii. For each length of liner two samples shall be taken at locations determined by the Engineer. The samples shall be clearly labelled with date taken and location. The samples shall be tested for average inside diameter, average outside diameter and minimum wall thickness in accordance with ASTM D2122, pipe stiffness at 5% deflection in accordance with ASTM D2412 and for the properties given in Table 2. The stiffness so measured shall meet, or exceed the stiffness requirements determined by calculation for that section of sewer line or the minimum specified stiffness whichever is the greater. Any material may be rejected for failing to meet any of the requirements of this specification.

C using a method and rate of cooling as recommended by the manufacturer before relieving the pressure in the liner. Care shall be taken in the release of the pressure to ensure that a vacuum will not be developed that could damage the newly installed liner pipe.

viii. The watertightness of the pipe shall be gauged while curing and under a positive head.

c) The finished lining shall be continuous over the entire length of a run

from manhole to manhole and be impervious and free of any leakage from the pipe to the surrounding ground and from the ground to inside the lined pipe.

d) The beginning and end of the liner pipe shall be sealed to the

rehabilitated pipeline and the manhole liner using a material that is compatible with the liner.

e) Immediately after installation the liner shall be tested to the requirements

of relevant section of the specification.

f) After the sewer is completely rehabilitated but before the sewage flow is returned the liner shall be inspected using CCTV in accordance with the requirements of Section 02700 of the specification and the Contractor shall provide the Engineer with a recording showing the completed work including the restored conditions.


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g) Any defects which will or could affect the integrity of the liner shall be repaired at the Contractor’s expense in a manner approved by the Engineer.

h) Wrinkles in the finished pipe which exceed 5% of the pipe diameter are

unacceptable and the liner shall be removed and a replacement liner installed to the approval of the Engineer.

3.8 DEFORMED AND REFORMED HDPE PIPE INSTALLATION

a) The Contractor shall retain the services of a licensed installer of the manufacturer of the deformed and reformed HDPE liner pipe sewer rehabilitation system to assist the Contractor during preparation and installation of the system to certify that the work has been performed in accordance with the manufacturer’s recommendations.


The Contractor shall obtain detailed installation instructions and procedures from the manufacturer for the actual installation of the deformed and reformed HDPE liner system. The requirements of ASTM F1606 shall also be satisfied.


surveyed and repaired to the requirements of this section of the specification prior to liner installation.

ii. A cable shall be strung through the existing sewer to be rehabilitated from upstream to downstream manholes and attached to the liner. The liner shall be pulled through the existing pipe by this cable.

iii. Care shall be taken not to damage the deformed liner pipe during installation by using appropriate sleeves and rollers to protect the liner.

iv. When the deformed pipe liner is in place it shall be cut and the pipe end closing assembly used for heat and pressure control within the liner shall be attached an secured at both pipe ends. Temperature and pressure measuring instruments shall be attached to both ends of the deformed HDPE liner to provide a continuous monitor of the temperature and pressure being applied to the liner.

v. Through the use of steam and air pressure the deformed pipe shall be reformed to conform to the existing pipe wall.

vi. The reformed HDPE liner shall be cooled in accordance with the manufacturer’s recommendations.

vii. Temperatures and pressures shall be monitored and recorded throughout the installation process to ensure that each phase of the process is achieved at the manufacturer’s recommended temperature and pressure limits.

viii. For each length of liner two samples shall be taken at locations determined by the Engineer. The samples shall be clearly labelled with date taken and location. The samples shall be tested for average inside diameter, average outside diameter and minimum


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wall thickness in accordance with ASTM D2122, pipe stiffness at 5% deflection in accordance with ASTM D2412 and for the properties given in Table 3. The stiffness so measured shall meet, or exceed the stiffness requirements determined by calculation for that section of sewer line or the minimum specified stiffness whichever is the greater. Any material may be rejected for failing to meet any of the requirements of this specification.

ix. The watertightness of the liner shall be gauged throughout the forming process.




rehabilitated pipeline and to the manhole liner using a material that is compatible with the liner.

e) Immediately after installation the liner shall be tested to the relevant

requirements of the specification.


g) Any defects which will or could affect the integrity of the liner shall be

repaired at the Contractor’s expense in a manner approved by the Engineer.

3.9 SPIRAL WOUND PIPE INSTALLATION

a) The Contractor shall retain the services of a licensed installer of the manufacturer of the spiral wound liner pipe sewer rehabilitation system to assist the Contractor during preparation and installation of the system to certify that the work has been performed in accordance with the manufacturer’s recommendations.


The Contractor shall obtain detailed installation instructions and procedures from the manufacturer for the actual installation of the spiral wound liner system. The requirements of ASTM F1741 shall also be satisfied.



ii. The liner shall be installed into the sewer line by the use of a winding machine placed at the bottom of the manhole, with the liner


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being introduced at a diameter of approximately 25mm to 50mm less than the diameter of the sewer pipe to be rehabilitated and then expanded until it comes into intimate contact with the host pipe.

iii. The liner shall be joined by the use of a mechanical locking strip. The strip shall have the same, or better, mechanical and chemical resistance properties than that of the liner material. The joint shall be continuous and watertight for the full length of the sewer.

iv. For each length of liner a sample shall be prepared prior to the winding machine being placed into the manhole. A length of pipe shall be formed from the same batch of material to be used in the installation. The length of sample shall be such that three lengths may be cut and tested in accordance with ASTM D2412 for pipe stiffness at 5% deflection and for the properties given in Table 4. The stiffness so measured shall meet, or exceed the stiffness requirements determined by calculation for that section of sewer line or the minimum specifies stiffness whichever is the greater. Any material may be rejected for failure to meet any of the requirements of this specification.




rehabilitated pipeline and to the manhole liner using a material that is compatible with the liner.

e) Immediately after installation the liner shall be tested to the requirements



g) Any defects which will or could affect the integrity of the liner shall be


3.10 SLIPLINING INSTALLATION

a) The Contractor shall retain the services of a licensed installer of the manufacturer of the slipliner pipe sewer rehabilitation system to assist the Contractor during preparation and installation of the system to certify that the work has been performed in accordance with the manufacturer’s recommendations.


The Contractor shall obtain detailed installation instructions and


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procedures from the manufacturer for the actual sliplining/swagelining installation. The requirements of ASTM F585 shall also be satisfied.



ii. Sections of slipliner shall be field jointed in the manhole or insertion pit using low profile spigot and socket joints, butt fusion joints or other type as recommended by the slipliner manufacturer.

iii. The slipliner shall be pushed/pulled into the sewer as appropriate. The length of the liner pipe to be inserted at any one time shall be governed by the capacity of the installation equipment and the consideration of the size and condition of the sewer. Precautions shall be taken to protect the slipliner from scouring of its external surface as it is being installed into the sewer.

iv. The slipliner shall be allowed to recover to its original length. The time shall be at least equal to the time to install liner.

v. Manhole benching and lining shall be reconstructed to match new invert elevations to the requirements of clause 3.11 below and to the satisfaction of the Engineer.

vi. The measured liner stiffness shall meet, or exceed the stiffness requirements determined by calculation for that section of sewer line or the minimum specified stiffness whichever is the greater. Any material may be rejected for failure to meet any of the requirements of this specification.



d) Immediately after installation the liner shall be tested to the requirements


e) After the sewer is completely rehabilitated but before the sewage flow is returned the liner shall be inspected using CCTV in accordance with the requirements of Section 02700 of the specification and the Contractor shall provide the Engineer with a recording showing the completed work including the restored conditions.

f) Any defects which will or could affect the integrity of the liner shall be


3.11 SEWER MANHOLE REHABILITATION

a) It is the intent of this portion of the work to provide for all aspects of sewer manhole rehabilitation including type of repair, methods of repair, and the materials that are appropriate for each manhole scheduled for rehabilitation. Any manhole or individual element of the manhole which in the opinion of the Contractor cannot be rehabilitated shall be reported


(ADSSC)



to the Engineer for his confirmation that the Contractor’s opinion is correct.

b) Sewer manhole rehabilitation includes the following procedures:

i. Rehabilitation of manhole walls and bases by plugging, patching,

and coating with mortars, coatings, sealants and liners to improve the structural condition, eliminate infiltration, and provide corrosion protection.

ii. Reinstallation or replacement of manhole frames and covers to adjust manhole to grade, eliminate infiltration under frame, and eliminate inflow through cover.

iii. Removal and replacement of ladders, handrails and sealing plates. iv. Installation of safety chains and grab bars as required by the

Engineer’s instructions.

c) However the rehabilitation work may only be required for one, some or all of the above procedures as agreed with the Engineer.

d) Rehabilitation of manholes.

i. Remove all defective linings in existing manholes and other

structures, including areas of lining covering leakage points. ii. Break out defective concrete to sound concrete surface. iii. The Contractor shall take all necessary precautions to prevent

falling debris from damaging the manhole and/or entering the sewer. iv. Surface preparation on bare concrete surfaces shall consist of

thorough cleaning to remove all loose material and surface contaminants.

Cleaning may be accomplished by waterblasting, sandblasting,

or applying a 10 percent solution of muriatic acid or hydrochloric acid over all surfaces. If an acid solution is used, the surface shall be thoroughly rinsed and neutralised prior to the application of mortars and coatings.

e) After surface preparation and prior to the application of mortars, coatings

and linings infiltration shall be stopped by sealing as specified in Clause 3.4.

f) Apply approved epoxy bonding agent and reinstate concrete using an

approved concrete repair material.

g) The materials used shall be designed, manufactured and intended for sewer manhole rehabilitation and the specific application in which they are used. The materials shall be supplied in factory-labelled containers. All materials shall be mixed and applied in accordance with the manufacturers written instructions. Materials used for plugging holes and stopping active hydrostatic infiltration shall be:

i. A premixed portland cement-based hydraulic cement consisting of


(ADSSC)



portland cement, graded silica aggregates, special plasticising and accelerating agents. It shall not contain chlorides, gypsum, plasters, iron particles, or gas-forming agents or promote the corrosion of steel it may come in contact with. Set time approximately not exceeding 3 minutes. Ten-minute compressive strength approximately 3.5N/mm².

h) Patching, filling and repairing non-infiltration holes, cracks, and breaks in

manholes shall comprise a premixed portland cement-based hydraulic cement consisting of portland cement, graded silica aggregates, special plasticising and accelerating agents. It shall not contain chlorides, gypsum, plasters, iron particles, or gas-forming agents or promote the corrosion of steel it may come in contact with. Set time approximately 3 minutes or 20 minutes to suit application. One-hour compressive strength approximately 4.2N/mm2

.

i) Coating for waterproofing, corrosion protection, and strengthening of damp manholes:

i. A liquid polymer modified hydraulic waterproof coating which shall

provide a secure bond. Usually applied with a brush to surfaces without cracks or voids wider than 1.5 mm. Cure time approximately 1.5 hours.

ii. A 100% solids, three-component system consisting of a two-component epoxy resin and a special blend of fillers which shall provide a secure bond.

j) Epoxy resin without fillers may be applied with a brush for waterproofing

and corrosion protection. The resin with fillers is applied with a trowel to a thickness of 3mm to 12mm. Initial cure time approximately 4 hours.

k) All surfaces of an existing GRP lined manhole, where the liner has been

removed as a result of the rehabilitation works, shall receive an insitu GRP lamination to the requirements of the specification. In places where other liner materials are encountered proposals for the repair of the liner shall be submitted to the Engineer for his approval.

l) Application of all materials shall be in accordance with the material

manufacturer’s recommendations.

m) Manhole frame and cover reinstallation or replacement. The Contractor shall, upon receiving an instruction from the Engineer, remove the existing manhole frame and cover. If the frame and cover are to be replaced, the Contractor will dispose of them. The Contractor shall then adjust the elevation of the manhole as required. The manholes shall be raised by adding a sufficient number of courses of concrete blocks to obtain the desired elevation. It shall be the responsibility of the Contractor, at no additional cost to ADSSC, to repair any portion of the manhole which is damaged when the existing frame and cover are removed. The Contractor shall then re-install or replace the manhole frame and cover. Replacement frames and covers shall be as specified.


(ADSSC)



n) Manhole rehabilitation acceptance. After the manhole rehabilitation work

has been completed, the manhole shall be visually inspected by the Contractor in the presence of the Engineer. Any defects which will or could affect the integrity of the manhole shall be repaired at the Contractor’s expense in a manner approved by the Engineer. In addition the Contractor will be required within one year to visually inspect the manholes which were rehabilitated. Any work that has become defective shall be redone by the Contractor at no additional expense to ADSSC.

END OF SECTION

15-division 2-section 02600 sewer rehabilitation-version 2.0

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