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Friday, June 25, 2021

METHOD STATEMENT FOR CONCRETING OF PROTECTION SCREED

1.0 SCOPE
The intention of this method statement is to describe the procedure and responsibilities of the personnel involved in the concrete pouring for the protection screed.

2.0 RESPONSIBILITY

The Project Manager is overall responsible for all aspects of the work/project.

The Project Site Engineers are responsible for the proper execution, arrangement, coordination, and supervision of quality, safety, and delivery of the work.

The Approved Concrete Ready Mix Supplier is responsible for the continuous delivery of concrete as per the approved design mix and project specifications, from batching to transporting, controlling temperature and slump, and taking required concrete test cube samples upon arrival at the site.

The QA/QC Manager & Engineers shall ensure that the execution team follows this method statement and implements the site inspection procedures. The QA/QC Engineers shall monitor, check, control, and document the quality of concrete delivered to the site and the quality of work throughout the entire casting process.

The Safety Engineer or Safety Officer will ensure the implementation of safety measures at the worksite.

3.0 MATERIALS & EQUIPMENT

The concrete design mix for the protection screed should be approved by the engineers before execution.

Polyethylene sheets should be approved by the engineers or as recommended by the waterproofing manufacturer/supplier.

Secured approved shop drawings for raft foundation lift pits, manholes, etc., should be available for reference of screed levels.

4.0 EXECUTION

Inspection of completed layers of liquid damp proofing materials should be carried out to ensure no damage or unsatisfactory workmanship.

Install the approved gauge of polyethylene sheets as per the method statement of the waterproofing manufacturer/supplier.

Proceed with concreting the protection screed to the required thickness (minimum 50 mm) after rectifying any unsatisfactory conditions.

5.0 PREPARATION

Clean and prepare the applied bituminous damp-proof surface according to the manufacturer/supplier's recommendations on blinding.

Remove all dirt, deleterious materials, and other substances that may damage the waterproofing during the concrete pouring process.

Establish the reference elevation of 1.0 meter from SSL and the high-level elevation of the concrete protection screed as per the approved shop drawing and specification.

Install approved polyethylene sheets on top of the applied damp-proofing, as per the manufacturer's/supplier's method statement.

Install the forms along the construction joints of the protection screed.

Obtain approval from the engineers before the application or placement of concrete.

6.0 APPLICATION

Determine the weather conditions (hot, sandstorm, rainy, or sunny) before placing the concrete order with the ready-mix supplier.

Sprinkle clean water on top of the polyethylene sheet to promote bonding with the concrete.

When the ready-mix concrete arrives, inform the engineers and conduct QC testing, such as slump test, temperature check, and volume at the concrete checkpoint.

Use high slump or self-compacting ready-mix concrete to avoid using a vibrator, which could cause misalignment of the polyethylene sheet.

Place the ready-mix concrete using a concrete mobile pump or direct pouring with a chute, following the basic method statement for placing concrete using a concrete mobile pump or direct pouring.

Once the ready-mix concrete is placed, level the concrete according to the approved screed level.

Finish the screed surface as required, according to the specification or as approved by the engineers.

Once the initial set of the concrete is complete, immediately apply an approved curing compound or use water curing to prevent thermal cracking.

7.0 FIELD QUALITY CONTROL

Monitor the temperature and slump of ready-mix concrete.

Ensure the quality of the delivered ready-mix concrete at the site.

Ensure that concrete cube sampling is conducted as per the specifications.

Ensure quality workmanship and required thickness during the pouring activity.

8.0 SAFETY PRECAUTIONS

Prime importance shall be given to the safety of personnel and the protection of utility services. Ensure that personnel involved are thoroughly aware of the company’s safety regulations.

Any machinery and equipment must be operated only by well-trained and experienced personnel.

Protective clothing and equipment will be necessary. Ensure that any special protective clothing or equipment required, such as helmets, eye protection, ear defenders, visibility vests, etc., is ordered and available for use on-site. Subcontractors should be made aware of any site requirements, especially regarding safety helmets.

Instruct staff in the correct handling and lifting of materials, as improper handling could cause injuries to the hands.

A risk assessment letter should be issued by the Safety In-charge before the start of the activity and posted at the working area during the activity.

9.0 REFERENCE DOCUMENTS

Project contract specifications

Project contract drawings and general notes

 


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