Method Statement for Casting of Blinding Concrete for Box Culvert and Installation of Precast Box Culvert Units
TABLE OF CONTENTS
- Purpose
- Scope of Work
- Definitions
- References
- Materials
- Plant & Equipment
- Safety
- Prior Activities
- Procedure
- Responsibilities
- Attachments
1. Purpose
1.1 To ensure that the Blinding of Box Culverts and Installation of Precast Box Culvert units are 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.
2. Scope of Work
2.1 This procedure is applicable to the following works associated with the Project titled,
New 2K Runway – Main Runway Works – contract number NRTW-1008-CN
2.2 This method statement outlines the procedures to be followed in casting of Blinding for
Box Culvert and installation of precast units at locations shown on Contract drawings
and as directed by the Engineer.
3. Definitions
3.1 CM Construction Manager
3.2 SE Site Engineer
3.3 CS Chief Surveyor
3.4 ME Material Engineer
3.5 ESHO Environmental, Safety, and Health Officer
3.6 ITP Inspection and Testing Plan
4. References
4.1 Specifications : Vol.3 – Section 9 – Part A – General, Civil and Mechanical Infrastructure
4.2 Drawings : Vol 2 – Section 8 – Part B – Civil, Mechanical and Navaids.
4.3 BOQ : Bill No. 7
5. Material
5.1 Concrete grade 40/20/S
5.2 Formwork ( Timber and Aluminium beams )
5.3 Polyethylene joint filler
5.4 Polysulphide joint sealant
5.6 Polythene sheet
5.7 Nonshrink Grout
6. Tools & Equipments:
6.1 Spirit level
6.2 Measuring tape
6.3 Hammer
6.4 Hand planer
6.5 Carpenter chisel
6.6 Plastic trowel
6.7 Steel trowel
6.8 Broom
6.9 Safety Helmet
6.10 Rain Boot
6.11 Hand Gloves
6.12 Mask
6.13 Wire Nails
6.14 Air compressor
6.15 Generator
6.16 Grinder
6.17 Electric saw
6.18 Concrete vibrator
6.19 Hydraulic Crane
6.20 Trailers
7. Safety
7.1 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.
7.2 Site Foreman/Supervisor will enforce that Personal Protective Equipment be worn by site personnel at all times during construction activities.
7.3 Heat Stress Training will be provided.
7.4 Provisions of adequate cool drinking water, shade, and salt tablets and or lemon will be in place.
7.5 Plant and Equipment will be provided with back-up alarms, lights, and all other applicable safety devices. Certificates of worthiness will be provided before the equipment is used.
7.6 For AOA work, safety requirements as defined per Section 107 will be implemented. Specific safety training will be provided to personnel for AOA work.
8. Prior Activities
8.1 Box Culvert shop drawings to be approved by the Engineer.
8.2 Excavation and foundation preparation will be carried out as per submitted method statement
1008-OAJ-MS-1025.
9. Procedure
9.1 Casting of Blinding
9.1.1 Once the foundation level is approved by the Engineer, the CS shall mark the setting out and fix reference levels for blinding concrete.
9.1.2 The formwork ( around 120mm height) shall be fixed and inspected by the Engineer’s Inspector.
9.1.3 Polythene sheet 1000 Gauge shall be laid and 100mm thick concrete grade 40/20/S shall be poured, vibrated and leveled to the approved levels.
9.1.4 Special care should be taken to produce smooth and correct final level, to avoid any surface irregularity while installing the precast Box Culvert units.
9.1.5 The concrete shall be protected by polythene sheet after finishing and wet hessian covered with
polythene sheet after final set.
9.1.6 Concrete surface shall be kept continuously and thoroughly wet for a curing period of 7 days.
9.2 Installation of Precast Box Culvert Units
9.2.1 The precast units shall be delivered to the site by Trailers.
9.2.2 The units shall be unloaded on site by a hydraulic Crane.
9.2.3 The CS shall mark the setting out on the surface of the blinding.
9.2.4 Once the blinding curing is completed, the installation of precast units shall start
by using hydraulic Crane carrying the units from the lifting anchors as shown in the shop drawings.
9.2.5 Electric Grinder shall be used to correct any small irregularity in Blinding surface before placing
the precast units.
9.2.6 Approved polyethylene joint filler and joint sealant shall be installed at each joint as shown in the approved shop drawings and as per the Manufacturer’s (1008-OAJ-MS-AM 001) Method Statement
9.2.7 Approved Nonshrink grout shall be used to fill the recesses at Lifting Hooks and Lifting
Anchors.
9.2.8 Approved Brush applied Tanking Membrane and Protection Board shall be applied to the external surfaces of Box Culvert as per the Manufacturer’s Method Statement.
Note
The associated structures to Box Culvert (Catchpit , Access Chamber , Open Channel to Box Culvert Transition Structure , Retention Pond Culvert Outflow , etc.) shall be cast in situ as per the approved as noted Method Statement no. 1008-OAJ-MS-1014 (Manhole Construction).
10. Responsibilities
- The CM will coordinate with SE and ensure that necessary resources to implement the approved method statement have been allocated to the task.
- The SE will ensure that the site preparation activities are conducted according to the approved method statement.
- The ME will ensure that the materials being used are in accordance to the project specifications and the approved method statement and ITP.
- The ESHO along with his team will ensure implementation of all ES&H procedures related to the nature of the works being carried out and in accordance with ES&H plan.