Objective of this method statement is to explain the procedure for the Installation of Cathodic Protection System for a construction project in compliance with local and international regulations.
This method statement identifies the work related general steps and necessary arrangements, scope of this document includes preparation of equipment, manpower, installation, rebar continuity test for critical & non critical structures, boss connectors for concrete foundations, corrosion monitoring probe pre & post Installation records etc.
Definitions & Abbreviations
QA/QC: Quality Assurance / Quality Control
HSE: Health, Safety & Environment
ITL: Independent Testing Laboratory
ITP: Inspection and Test Plan
RFI: Request for Inspection
AFC: Approved for Construction
MST: Construction Method Statement
Roles and Responsibilities
Project / Site Manager shall be responsible for the execution of this procedure and to ensure that cathodic protection works are undertaken in a safe manner, to the requisite quality and to the agreed timescale. He shall advice and co-ordinate with other subcontractors pertaining to access and interface requirements related to the cathodic protection works to be undertaken.
QA/QC Manager shall be responsible for the implementation, documentation and scheduling of all tests and inspections. He shall assign a competent QA/QC Inspector to perform / supervise the inspections and tests as mentioned herein.
QA/QC Inspector shall be responsible in all inspection and testing. He shall report all activities to his QA/QC Manager before and after any activity involving QA/QC in the project.
Section Engineer shall be responsible for the site implementation of this procedure including control and safety of the workers. He shall assign a Site Engineer and Cathodic Protection Technicians to oversee daily work progress and safety.
Site Engineer shall be responsible for the activities such as, controlling manpower and equipment involved for the assigned activity, control personnel’s to implement a safe working method and prepare reports of daily activities
Safety Engineer:
Shall assist project team for the compliance of safe working methods.
He shall assess the hazards in the workplace and formulate remedial actions to eliminate, contain or reduce them.
Also he shall advise Construction Manager, Site Engineer and Discipline supervisors concerning all safety related matters on the job and has the authority to intervene, including stopping the job if work is being performed in an unsafe way.
He shall ensure that the works must proceed in accordance with project HSE plan and that works are undertaken in a safe and proper manner and are compliant with good working practices.
Safety Officer shall be responsible for the implementation of safe working practices on site. He is assigned to ensure that all works are in accordance with project HSE procedures.
Surveyor shall be responsible for giving an exact elevation and coordinates as per drawings.
Civil Foreman shall be responsible for the site implementation of civil works as per approved drawings. He shall supervise the gang leaders and skilled workers to complete the job in proper manner with full control of safety precautions and practices.
Technician / welder shall ensure that installation for the cathodic protection system are done as per the approved procedures and drawings, also he shall prepare and maintain the records for the required tests.
Labor / Helper shall be executing any activities assigned to him on site, (i.e. assist safety, Surveyor, etc.) and should follow instructions from his supervisor.
Equipment & Tools
- Hand tools for this activity
- Potential multimeter
- Crimping tool
- Power Drill
- Generator
- Welding equipment
General Requirements for Cathodic Protection System Installation
Before the start of each day’s operation, all necessary permits will be obtained from the main contractor/client as applicable.
Permit to Work document must be updated and approved prior to proceeding / starting a particular activity.
Equipment’s will have its own inspection stickers and shall be inspected and approved by client/consultant before use.
Personnel shall have safety induction and trained prior to site mobilization.
Manpower List
- Construction Manager
- Section Engineer
- Safety Officer
- Surveyor
- Civil Foremen
- Technician
- Welder
- Carpenters
- Labor/Helpers
Rebar Continuity Test
The basic criteria are to measure resistance at each location and between locations.
Test shall be conducted by using the precision ohmmeter, all instruments to be checked, calibrated, certified and approved prior to use.
Identify the locations and assign test location identifications.
Clean the rebar to metal finish by using the wire mesh.
Check continuity between rebars at different locations and between locations and with terminals reversed and record resistance values.
Any rebars failing the below criteria will be made continuous by means of continuity connections and continuity of each rebars in a single structure will be achieved.
The maximum allowable value shall be 1 ohm, any value more than 1 ohm shall be repaired.
Also fluctuating resistance values are treated as failed and to be repaired as above.
All the data obtained will be recorded in the approved/attached format.
Installation of Boss Connectors
Based on the structure design, locations shall be identified and the reinforcement of the structure shall be bonded to achieve electrical continuity and negative connection for future cathodic protection.
All reinforcing steel embedded in concrete shall be made electrically continuous during construction.
The following sections explain the steps to be followed in achieving continuity and monitoring measures.
Critical Structures:
Structures classifieds as critical structures the continuity shall be established between rebars embedded above and below ground concrete using galvanized steel wires, wrapped around and tied by GI Tie wires wrapping around to 5 times to the horizontal / vertical rebars.
Non Critical Structures:
Structures classifieds as non critical structures the continuity shall be achieved by means of rebar to rebar contact by using GI wires used for normal reinforcement steel work.
The connection of Boss to the vertical rebars of column shall be Tack welded.
Bonding Procedure
Continuity wire shall be connected between the horizontal rebars , as each vertical rebar is tied to each of the horizontal rebar by means of tie wire and horizontal rebar travels maximum spread compared to the vertical rebar.
The following steps shall be followed to achieve electrical continuity.
Structural Continuity Bonding in Critical Structures
Identify the location for continuity bonding and negative connection.
Cut the required length of the 6mm2 Galvanized steel wire
Fix the wire to the bottom horizontal rebars by means of GI tie wire used for normal rebars and wrapped around 5 times on both directions.
The above shall be repeated with all the horizontal rebars in one location with single length of wire.
Check the installation by pulling and also check continuity of the joints.
Refer approved drawings for details.
Structural Negative Connection Point (Boss Terminal)
Structure negative bonding shall be achieved by connecting individual negative feeder cables to the boss connection.
Boss connection shall be fixed to the rebar by either directly fixing with suitable C crimps or Galvanized tie wire crimped to the boss and other end crimped to the structure rebar.
Location of boss connections shall be installed minimum one each for 64 m2 concrete surface area.
One boss connection shall be provided for foundation smaller than 64 m2.
Check the continuity and confirm the effectiveness of bonding by measuring the resistance at each location as per the procedure.
Post Installation Checks
Visual inspection of installation.
Rebar and boss connections and results shall be recorded in the test format given in the approved procedure.
Site Quality Control
Site management, Site Engineer, QA/QC inspector and safety officer will closely supervise and monitor all phases of work to ensure full compliance with the procedures and safe methods of working.
Inspection, test and recordings shall be carried out in accordance with the approved procedures and in accordance with the project specification.
Request for Inspection RFI will be issued for the final inspection and approval from client/consultant.
Unless otherwise shown on the Engineering drawings, items shall be installed in accordance with Project Standard Drawings.
Continuity shall be checked and the results shall be recorded before and after concrete pouring.
Vertical rebars and spiral rebars shall also be connected with wire rope and GI Tie wire wrapped around 5 times.
HSE Compliance Requirements
All works shall be in compliance with the local laws and regulations and international standards, codes and project HSE requirements.
Contractors shall comply with this method statement, Job Safety Analysis (JSA) and will follow good practice as per legislation.
A STARRT meeting with the working crew shall be complied with prior to commencement of work.
All persons shall wear personal protective equipment (PPE), e.g. safety helmets, safety glasses, coverall, safety shoes, hand gloves, etc. shall be provided within the site, PPE must be of approved type.
Any incident/injury/near miss will be reported immediately to the appropriate authorities.
All works should adhere to the Job Safety Analysis. JSA will be discussed daily with crew to familiarize everybody with safe work procedures.
In case of injury and/or illness, notification will be corresponded.
Main contractor and his Subcontractor’s site engineer shall ensure that his team follows safety rules and regulations. He will also initiate the daily tool box meeting and maintain record of periodic and monthly inspection records.
Waste dumping will be as per guidelines.
All mobile plant generators, machines will have drip trays open underneath, properly grounded and fire extinguishers available.
All power tools and if any lifting equipment available to be color coded as per procedure.
Protective Measures
Contractor shall ensure that their own personnel are trained in:
- Health, Safety & Environmental Requirements and Regulations.
- Potential Risks and Impacts, Protection Measures, PPE Usage, Sanitation & Hygiene
- Emergency Response Plan (ERP)
Any issues regarding HSE client shall be fully informed at all times.
Sufficient shaded areas and drinking water to be provided to the workforce, in extreme hot weather, and working hours should followed those advised by government decree.
In severe sandstorm all works to be suspended.
In addition all employees and subcontractor employees on site shall have trainings through client Safety Induction for site safety, health, environmental and security prior to mobilization to work activities.
Other training courses will be attended as required by client.
Plant & Equipment Control
All drivers and operators shall be competent persons and must have licenses and competency certificates where appropriate.
All the project site traffic rules shall be strictly obeyed.
Implement vehicle/equipment speed limits as per site regulations.
No Overtaking on site unless the other vehicle is in stationary position.
Plant and equipment to be fully licensed and regularly serviced and inspected also must have third party certificates.
Any accident / injury / near miss will be reported immediately to the appropriate authorities.
All contractors will strictly follow the approved procedures for site access of all plant, equipment and operatives.
Attachments:
Inspection and Test Plan ITP
Datasheets for Cathodic Protection
Job Safety Analysis JSA