Method Statement for Grouting of Pipes in Stormwater Single and Double Pipe Catchpits

CONTENTS

1. Purpose

• Scope of Work

• Definitions

• References

• Materials

• Tools, Plant  & Equipment

• Safety

• Prior Activities

• Procedure

1. Responsibilities

1. Attachments

1. Purpose

1.1       To ensure that the grouting of pipes in stormwater catchpits is executed safely and in accordance with the contract requirements and that all quality assurance/ control activities are conducted in a systematic manner, works are inspected and conformance is verified and documented.

• Scope of Work

• This procedure is applicable to the following works associated with the Project titled, “New 2K Runway – Main Runway Works” – Contract Number NRTW-1008-CN.

• This method statement outlines the procedures to be followed in the grouting of pipes in stormwater single and double pipe catchpits (Types 1, 2 & 3).

• Definitions

• CM                  Construction Manager
  • SE                   Site Engineer
  • CS                   Chief Surveyor
  • ME                   Material Engineer
  • ESHO              Environmental, Safety, and Health Officer
  • ITP                  Inspection and Testing Plan
  • AHA                 Activity Hazard Analysis
  • JHA                 Job Hazard Analysis

• References

• Specifications:             Volume 3 – Section 9 – Part A – General, Civil and Mechanical Infrastructure

• Drawings:                    Volume 2 – Section 8 – Part B – Civil, Mechanical and Navaids

• BOQ:                           Bill No. 7

• Materials       

• Concrete Grade 45/10/C
  • Curing Compound (resin based)
  • ISOREX UMO Oil Based Form Release Agent
  • Acrylic Sealant or Gypsum Powder
  • Water (complying to Clause 200.12A of contract specifications)
  • Formwork/Shuttering
  • Hessian Cloth
  • Polythene Sheet
  • Warning Tapes
  • Safety Barrier
  • Traffic Cones

• Tools, Plant & Equipments:

• Mobile Crane (if required)
  • Concrete Mixer
  • Concrete Vibrators
  • Concrete Temperature Gauge
  • Slump Cone and Cube Moulds
  • Surveying Instruments (if required)
  • Ladders
  • Light Towers (if required)
  • Electrical Grinder / Saw
  • Generator
  • Air Compressor
  • Hand Tamping Tools (for cleaning and surface preparation)
  • Trowel
  • Personal Protective Equipment

• Safety

• Prior to the commencement of any activities, the workforce will receive an induction talk on the project site safety requirements. This induction talk will include both activity safety issues, as well as general safety requirements.

• Front line supervisor will ensure that Personal Protective Equipment is worn by site personnel at all times during construction activities.

• Heat Stress Training will be provided.
  • Adequate cool drinking water, shade, and salt water tablets will be in place.

• Plant and Equipment will be provided with back-up alarms, lights, and all other applicable safety devices.

• For AOA work, safety requirements as defined per Section 107 will be implemented. Specific safety training will be provided to personnel for AOA work.

• Prior Activities

• Prior to grouting, it will be ensured that all necessary equipment and tools are available.

• All loose dust and dirt from the concrete substrate will be removed using an air compressor.  The surfaces will be roughened by chipping or other mechanical means to assure bond of the concrete grout to existing concrete.

• It will be ensured that the surfaces to be grouted shall be clean, dry and free from dust, grease, oil, dirt laitance and other contaminants.

• The substrate will be saturated with water for at least two hours before placing grout, but ensuring that there is no free standing water just before placing grout.

• All of the necessary shuttering/formwork will be prepared and made ready.  Forms will be treated with ISOREX UMO form release agent.

• Procedure

• Construct and install a temporary shutter with a hole in the middle to allow the pipe to pass through both on the placing and opposite side.  Refer to the attached sketch for arrangement of the temporary shuttering.

• Seal any gap between the pipe periphery and shutter with an acrylic sealant.  Also, seal the edges of the shutter with sealant or gypsum powder to ensure that grout will not leak.  Ensure that the shutters are strong, braced and absolutely leak-proof.

• Calculate the total volume of concrete that will be required to fill the hole and start pouring the Class 45/10/C concrete grout.

• Concrete vibrators must be used to ensure that the concrete grout is compacted properly and there are no gaps in the concrete grout.
  • Cover the exposed section with a wet Hessian cloth and polythene sheet.

• Shutters can be removed after 48 hours and exposed concrete grout cured with a wet Hessian-polythene sheet or alternatively with resin based curing compound

• Testing of concrete grout (cubes) shall be carried out as detailed in Item 4.3 of the attached ITP.

• After the above works are completed and approved by the Engineer, waterproofing and backfilling operations will commence in accordance with the approved method statements for these activities.

1. Responsibilities

1. The CM will coordinate with SE and ensure that all necessary resources to implement the approved method statement, JHA, and AHA have been allocated to the task.

1. The SE will ensure that the site preparation activities are conducted according to the approved method statement, JHA and AHA.  The SE will also ensure that all in-situ tests, as required by the ITP, are implemented.

1. The ME will ensure that the materials being used are in accordance with the project specifications and the approved material submittals.

1. It is the site supervisor’s responsibility to organize the work in a safe manner to ensure that safety and protective equipment are being properly utilized.  He must also ensure that the AHA and JHA are implemented and the approved method statement procedure is followed and the ITP is applied.