Method Statement of Slab on grade

Cutting joints Installing reinforcement Casting concreteCasting lean concrete of ground slabPrevious stage... + The reinforced steel boxes 4x8 cm are fixing to plywood to result the form

Reviewed by Nguy n Hoàng Trinhễ Site Manager

Approved by Nguy n Văn Trungễ Project Manager

1 INTRODUCTION 5

1.1 GENERAL 5

1.2 DEFINITIONS: 5

2 BUILDING DESCRIPTION: 5

3 ORGANIZATION CHART 9

3.1 Organization Chart (Factory No.1) 9

3.2 Assignment 10

4 SCHEDULE 10

5 SPECIFIC STANDARD 10

6 SCOPE OF WORKS: 11

7 FLOW CHART AND DIRECTION OF WORK 12

8 PREPARATION WORKS 13

9 CONSTRUCTION METHOD 14

9.1 Casting schedule: 14

9.2 Jointing: 15

a Control joints 15

b Construction joints: 16

c Isolation joints: 17

9.3 PVC sheets 18

9.4 Steel work 18

9.5 Built-in steel angle: 19

9.6 Concrete work 20

a Construction joint: 20

b Supply and placement of concrete: 20

c Vibrating concrete: 21

d Floor finishing 21

e Application of hardeners: 22

11.1 Type of material: 24

11.2 Materials handling, storage and delivery 25

12 QUALITY CONTROL 25

13 RISK ASSESSMENT 27

14 SAFETY 27

15 APPENDIX 27

1 INTRODUCTION

1.1 GENERAL

This document describes the procedures and method for carrying out the construction works for Slab onGrade of building factory No.1 This method statement will be applied after completion of the RCstructures such as foundations, ground beams, columns and the works of soil stabilization and leanconcrete on the ground The constructions of those work items were carried out by previous stage;therefore they will no longer discuss in this method statement

1.2 DEFINITIONS:

PROJECT PARTICULARS:

Project name : SMC MANUFACTURING (VIET NAM) FACTORY-PHASE 1 PROJECT

Address : Long Duc Industrial Park, Long Duc Ward, Long Thanh District, Dong Nai Province,

Viet Nam

PARTY:

Client/ Owner : SMC MANUFACTURING VIETNAM CO., LTD

Contractor : KAJIMA OVERSEAS ASEA PTE LTD

Responsible for the supervision of Contractors who will construct the podium and all related activities as outlined in this procedure

SCOPE OF WORK

The works to be carried out by Sub-Contractor (ACSC) and shall apply for works at Factory No.1 of SMC

MANUFACTURING (VIET NAM) FACTORY- PHASE 1 PROJECT

1 Construction Reinforcement Concrete Structure works included:

a Pile head treatment

Factory No.1 are located at the corner of Road No.D5 &N2-5 in Long Duc Industrial park as below

Description:

 Building purpose : Factory

 Foundation : Spun piles (D300, 350, 400 mm)

 Structure : RC structures + steel rafter; Slab on grade

o Factory Ground floor slab : 300 mm thk

o Storage/Utilities Ground Floor slab : 150 mm thk

GFL±0 GFL GFL+7.250 1FL GFL+11.900 T O.B EAM GFL+13.650 T R.BEAM

CO RRI DO R Z INC RO OF SHEET 11600

1/ 20

DO WN SPO UT GUARD PO ST ( 100?, H=1500) LOADI NG BAY

F AC T O R Y- 02

C O R R ID O R Z I N C R O O F SH EET 1/ 20

Deputy Site Manager 2

LÊ LONG HẬU (MP: 093 734 3055)

haull@acsc.com.vn

Site Engineers

Nguyễn Minh Tuấn (MP: 098 314 5069)

Nguyễn Văn Hào (MP: 0938.722.730)

Phương Phương Việt Company

Deputy Site Manager 1

NGUYỄN TRÍ KHOA (MP: 0937 229 680)

ngtrikhoa@acsc.com.vn

Safety Supervisors

Đỗ Vũ Quyền Anh (MP:090 853 1908)

3.2 Assignment

NGUYỄN VĂN HÀO BÙI CÔNG HUYNHLÊ VĂN TUẤT

4 SCHEDULE

Construction Schedule of 1FL beams/slab is attached in Appendix-2

5 SPECIFIC STANDARD

Reinforced Concrete Beams/slab shall be carried out in accordance with the requirements of:

 SMC MANUFACTURING (VIET NAM) FACTORY-PHASE 1 PROJECT Specification for beam/slab works

 Current Vietnamese Construction Standards

+ TCVN 5593 : 1991 Vietnamese standard 5593-1991 (Building engineering work - Permissible tolerances in geometry)

+ TCVN 1651-2008 Vietnamese standard 1651-2008 ( Steel for the reinforcement concrete, part1+2)

+ TCVN 4453 – 1995 Vietnamese standard 4453-1995 (Concrete structures- codes for

construction, check and acceptance)

+ TCXDVN 371 - 2006 Vietnamese standard 371-2006 (Acceptance of constructional quality of

building works)

 Related Materials approved by KAJIMA & Owner

6 SCOPE OF WORKS:

The Slab on Grade in factory No.1 include main area 140m long x 60m (8400 m2) wide and the sub-area alonggrid A & E (120 m long x 4.50 m wide, 1080 m2)

 The designed load capacities of Slabs are classified as below:

7 FLOW CHART AND DIRECTION OF WORK

The work sequence of construction the Slab on grade is shown at the following flow chart

Cutting joints

Installing reinforcement

Casting concreteCasting lean concrete of ground slabPrevious stage

8 PREPARATION WORKS

 Surface preparation

+ Check the finished level of lean concrete Establish as-built drawings

+ Chip out and remove all debris, loose material on top surface of s

+ Cleaning the surface on the top of with water

+ Cleaning any laitance, dirt, dust on the starter bars

 Pre-fabricate formwork

+ Plywood are cut in compliance with design width

+ The reinforced steel boxes 4x8 (cm) are fixing to plywood to result the formwork panels.+ The formwork panels will be transported to site near the construction area

+ To ensure the fair-face formwork, the plywood will be used with maximum 4 cycles

 Pre-Fabricate Steel rebar

+ Obtain approved shop drawings and Bar Bending Schedule

+ Manufacturing steel rebar

+ Casting concrete block for spacer

+ Deliver steel rebar to site and stock near construction area

+ Install the starter bars of Ground slab, if any

+ Concrete blocks will be used as spacer for side in order to keep the appropriate concrete covering Spacers will be pre-made with fine aggregate concrete, grade B20 They are shaped by casting in PVC mould D42- D49 (mm) Their heights are depended on the thickness of concrete

cover (4cm) determined in Technical Specification for each kind of structures The concrete

proportion is proposed for one mix as below:

+ Cover the RC structures can be affected during casting concrete

+ Prepare the location for concrete pump

+ Order the concrete

9 CONSTRUCTION METHOD

9.1 Casting schedule:

The casting concrete of Slab On Grade will be divided into two zones:

- Zone 1 :

This zone enclosed by the perimeter ground beams of grids A, E, 1, 15 (approximate 8400 m2)

In this zone, the slab is 300 mm thk., and finished level is mostly GL +0.00m

Most of concrete work of Slab on Grade is in this zone

To ensure the quality of concrete work and finishing, the casting in this zone will be divided into

15 stages on each area 30m long x 20 m wide as illustrated above

In each stage, the concrete slab will be done following the sequence:

 1st : Casting of Isolation blocks around the related columns

 2nd: Casting the Slab

Zone 1

Zone 2

Zone 2

- Zone 2 :

This zone enclosed by the ground beams on grids A-A1 and E-E1 (approximate 1080 m2)The thickness, finished level, slope of each slab area in this zone varies depended on their designs

The casting concrete in this zone will be done one by one to facilitate the quality control See details in the attached schedule

Isolation Joints

The control joints are formed by using cutting machine to cut on the slab 1 day after finishing

concrete work The lines to cut are marked on the slab with the support of theodolite

The cut line will be 5mm wide and 50 or 70mm deep depend on the thickness of the slabs

b Construction joints:

The construction joints will be located at the same location of controls joints so they will be treated by cutting

in the same way of control joints The construction joints will be formed by using formwork to separate eachcast Formwork will be made of rigid steel box with their top levels the same as floor finished level The toplevel of formwork is fixed by welding the steel boxes to the steel bars, which embedded securely into beddingconcrete

c Isolation joints:

There are two applications of isolation joints:

- Isolation joints along the ground beams

- Isolation joints around the columns

The isolation joints are formed by placing the Styrofoam (Extruded Polystyrene Foam) sheet 15mm

thk before casting concrete

After the slabs completed, a groove will be made on top by removing styrofoam 15mm deep and replacing it with sealant such as Sikaflex

9.3 PVC sheets

The PVC sheets will be installed on the bedding concrete before the installation of reinforcement with the thickness designed as below:

- PVC sheet 0.15mm : For all areas of Slab on Grade, except storage areas

- PVC sheet 0.30mm: For the storage areas as shown below:

 At Construction joints, the smooth dowel bars D12 will be installed at spacing 500 mm as shown

below before 1st casting The dowel bars will be support to right position with the D10underneath, which are supported by bar chairs D10@600

After finishing 1st cast, the exposed half of steel rebars will be painted to allow their movementlater

 Around the columns, reinforced rebar will be installed followed the design, typically as shownbelow:

9.5 Built-in steel angle:

As designed, the galvanize steel angles 5x50x50 mm will be installed for the shutter doors

There are 40 pieces, 4.05 m long to be installed at 17 positions before casting concrete

9.6 Concrete work

a Construction joint:

The construction joints will be determined as mentioned above

After finishing each cast, the formwork at construction joint will be removed All rubbish, laitanceand loose materials must be cleaned before any next installation of wire mesh

Before next casting, the construction joints will be cut to straighten the edge

b Supply and placement of concrete:

 Concrete will be transported from batching plant to site by mixer truck, the slump of concrete must be within 12 ± 2.0 (cm), initial setting time: 3 to 5 hours Ensure concrete will be

delivered in uniform and continuous supply for each concrete pouring The interval for each truck is to be on time to ensure a continuous flow of concrete Slump test is to be done for every truck

 Ready mixed concrete from mixer truck will be then discharge to concrete pump which is set-up near the construction area

 The concrete for Slab on Grade will be pumped to place from the far to the near corners of slab

c Vibrating concrete:

During concrete discharge, wet concrete shall be vibrated with a poker vibrator

especially at edges or beam area The vibrator shall be inserted vertically into the

- Application of floor hardener

- Floating (power trowel)

- Trowelling to Dense Smooth Finish

S t ri ki n g - o ff : Also known as screeding by using screed vibrator on the installed rails, is the process of

The rails are made from D20 steel pipes placed on top of the adjusting support D10 The rails are placed alongsides of each cast area at interval 3.7m to suit with length of screeding vibrator These supports will be fixed

to bedding concrete by drilling at spacing 0.8m

Flat

ne ss enhan c e me n t : The flatness of the floor is further enhances by flat floor tools and

equipment These equipment includes straight bars, hand trowel and bump cutter

e Application of hardeners:

Spread evenly floor hardener on semi-hardened concrete Divide the floor areas into grids

and ensure that appropriate amount of floor hardener is applied evenly onto each area Ensure

the workers use appropriate foot ware or platform so not to leave shoes mark on the concrete

underlying concrete Delay applying more hardener until moisture from the underlying concrete has been worked completely through the hardener

iv Immediately apply the remaining 1/3 of the specified amount of hardener The moisture from the underlying concrete must be completely worked through the hardener If this does not occur, the floor surface will delaminate

f Trowelling:

Float by using power trowel machine to get smooth surface

After the concrete has further stiffened, it should be machine or hand troweled to a blemish free finish Care should be taken not to trowel-burn the surface

g Curing:

Immediately after final troweling the slab will be cured To prevent surface delamination, wet curing should not begin until 24 hours after the final troweling During interim 24 hour period, cover concrete with plastic sheets to prevent rapid evaporation of surface moisture

The concrete will be cured with water during 7 days

9.7 Protection against Damage

The concrete slab shall be protected from damage due to load overstress, heavy shock and excessive vibration, surrounding the concrete area particularly during curing period

Construction load shall not be placed on newly completed floor

Traffic should be kept off the finished floor for 3 days or longer to avoid surface damages and scratch marking

All finish concrete surface shall be protected from damage by construction equipment, materials or other heavy tools with the rubber sheets at the locations where the other construction work to be executed, such

as brick work or plaster work

10.TOOL & EQUIPMENT

The equipment to be used for the construction of s is listed below

Diameter <8mm

11.MATERIALS

11.1 Type of material:

a/ Concrete: ready mixed concrete (supplied by KOA)

 For structure: grade B20

b/ Steel rebar: (supplied by KOA)

 With Diameter < 10mm: SR295

 With Diameter >10mm : SD390, B15-B35

c/ Form work:

11.2 Materials handling, storage and delivery

 Concrete : Ready- mixed concretes are transported from batching plant to site in concrete truck (6

to 12 m3 capacity) The concrete must be delivered to site within maximum 60 minutes depend

on the mix design of concrete supplier

 Formwork : Formwork will be pre-fabricated then stocked on yard with protection of plastic cover Before installing, the formwork will be transported to site and placed near the excavation The surface of formwork must be clean of dirt, loose concrete and to be applied the release agent, if needed

Unloading reinforcement from trailer by a suitable crane for lifting up reinforcement bundles.Prior to fabrication of reinforcement, samples shall be taken from each batch of each size of each delivery and tested for compliance in accordance with Quality Control procedures

 Other materials are keeping in storage and they are transported to the site work when they are

in used

12.QUALITY CONTROL

With regards to the quality control, all works shall be carried out following the established Project Quality Control Plan

 Installation of form work

+ Check by leveling machine, tape

+ Check tightness of formwork by visual

+ Check rigidity and stability of bracing

+ Lap length: Rebar SD390 Ribbed bar: 40d (tensile), 15d (compressive)

 Finishing concrete surface :

- Install rails for leveling the concrete to make sure the right finished level

- Before trowelling, using bump cutter to flatten the concrete surface in cutting high spots and filling low spots

- Making the first pass with pans in one direction then change direction by 90o to create flatter floor

Appendix-1: Construction Method Drawings

Appendix-2: Construction Schedule

Appendix 3: ITP for related works

Appendix 4: Risk assessment

Appendix 5: Safety check sheet

Appendix 6: Catalog of screed vibrator.

END