Concreting Method Statement

METHOD STATEMENT MANUAL CONCRETE WORKS 1.0

OBJECTIVE The objective of this procedure is to carry out concreting works.

2.0

SCOPE The scope of this method statement applies for all building and infrastructure projects.

3.0

REFERENCE Project Specification Pre-Concreting Checklist Drawings BS 8110 : 1985 Structural Use Of Concrete

4.0

DEFINITION Nil

5.0

RESPONSINILITY Site Engineer

6.0

MATERIAL / PRODUCT READY MIXED CONCRETE

7.0

HANDLING AND STORAGE OF MATERIALS Handling

:

Transport ready mixed concrete to location of pour by mixer trucks. Place concrete by using machinery and equipment outlined below.

Storage

:

Nil

8.0

PLANT, MACHINERY, EQUIPMENT & TOOLS Mobile cranes, Concreting Bucket, Vibrator, ETC as applicable.

9.0

PREPARATORY WORKS 9.1

Concrete Supply 9.1.1 Request for design mix based on the concrete grades specified on structural drawings from the Ready Mixed Concrete Supplier. 9.1.2 Submit the proposed design mix from suppliers to the structural consultant and seek for approval. 9.1.3 Upon acceptance of design mix by structural consultant, arrange for a trial mix at supplier's batching plant with the presence of the structural consultant. Conduct slump test, determine water cement ratio and takes samples cubes for compressive strength test. Ensure that the water cement ratio for trial mix meets the criteria in Table 1. As the ready mixed concrete suppliers are pre-appointed by client, the trial mix had been witnessed by client. Table 1 Grade 20 and below 30 40 45 50 60 70 80

Water cement ratio 0.55 0.50 0.45 0.35 0.35 0.30 0.28 0.25

9.1.4 Request the approved ready mixed concrete suppliers to submit the test results to client and structural consultant for review. 9.1.5 Place order from the approval ready mixed supplier for required amount of concrete at least one day before the actual pour.

9.2

Pre-Concreting Inspection 9.2.1 Prior to concreting works, carry out joint inspection with SO's Reps on structural member and verify the forms and steel reinforcement in compliance with the construction drawings and criteria in the Pre Concreting Checklist. Structural subcontractor to organise this inspection. 9.2.2 Check the alignments, verticality, levels and support of the erected forms. 9.2.3 Check the cleanliness of all forms and ensure that the forms are free from dust, mud or other debris. 9.2.4 Check steel reinforcement for number of bars, arrangement, spacing, concrete cover, spacer blocks, lapping and anchorage. 9.2.5 Check the positions, openings, sleeves and requirements for the M&E services are provided.

10.0

WORK METHODOLOGY 10.1

Receiving of Concrete 10.1.1 Carry out receiving inspection of ready mixed concrete as per Inspection & Test Plan and Delivery Order. 10.1.2 Verify the grade and quantity of concrete received. carry out slump test with the presence of resident engineer or Clerk of Work and ensure that the concrete slump meets the criteria defined in Table 2. Table 2

Grade of Concrete 40 and lower 40 and above

Slump Minimum (mm) 75 75

Maximum (mm) 150 200

10.1.3 Take concrete cube samples for every 100 cubic meters are specified in Table 3. Table 3 Grade of Concrete 40 and lower 40 and above

7 Days 1 1

No of Cubes 28 Days 3 3

56 Days Where required 3

10.1.4 Mark the location of pour of concrete received on the delivery docket and checklist as reference and identification. 10.2

Placing of Concrete 10.2.1 Provide adequate equipment, machinery and manpower to carry out the concreting works. 10.2.2 Place concrete on designated locations using concrete pumps ad/or crane assisted concrete buckets. 10.2.3 Start concreting from a fresh location or a predetermined construction joint and continue uninterrupted up to the next predetermined construction joint or to completion. 10.2.4 If concreting is to commence from a construction joint, roughen the joint before placing the concreting when wire mesh is not available. 10.2.5 Discharge concrete with less than 1.5 metres of vertical drop to avoid segregation of concrete. Place concrete from the lowest point to the final concrete level in one operation in horizontal layers. 10.2.6 Compact concrete by hand tamping and mechanical vibrators. Ensure that the concrete is worked in to the corners of the structural members.

10.3

Curing of Concrete 10.3.1 After the precast has set, carry out curing works as applicable.

10.4

Post-Concreting Inspection 10.4.1 Upon removals of formworks, carry out joint inspection with main contractor. 10.4.2 Check the structural members for accuracy on dimensions and concrete finished levels. Inspect the concrete surface for any honey combing, cracks and visibility of reinforcement bars. 10.4.3 Carry out joint inspection with the Clerk of Work and ensure that the structural members are satisfactory and meet the specifications and construction drawings. 10.4.4 For suspended slabs and beams, back propping is required.