Method Statement of RC suspended slab

CÔNG TY CỔ PHẦN XÂY LẮP THƯƠNG MẠI 2
Architects & Construction Service Corporation

METHOD STATEMENT
SMC Manufacturing (Viet nam) Factory-Phase 1 Project

RC 1FL SLAB

Ref No:
SMC-ACS-MS-00-CCW-003 Rev 01

ACSC- CONG TY CO PHAN XAY LAP THUONG MAI 2

SMC-Factory No.1/MS-RC 1FL slab

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Revision History
Revision
00
01

Date of issue
28/9/2015
30/9/2015

Purpose of issue (approved/ revision)

For Review
For Approval

Submitted by ACSC
Prepared by
Reviewed by
Approved by

Name
Lương Văn Lượng
Nguyễn Hoàng Trinh
Nguyễn Văn Trung

Position
Deputy Site Manager
Site Manager
Project Manager

Date

Signature

Approved by KOA
Checked by
QA-QC
QA-QC
HSE
KDA

Position

Date

Signature

Date

Signature

Reviewed by
Approved by

Approved by Client Name
Prepared by
Reviewed by

SMC-Factory No.1/MS-RC 1FL slab

Position

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Contents

SMC-Factory No.1/MS-RC 1FL slab

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1. INTRODUCTION
1.1. GENERAL
• This document describes the procedures and method of work for carrying out the construction works
for RC slab of building factory No.1. This method statement will be applied for first floor (level +7.250m).
Construction work of this slab will be repeatedly carried out after s underneath columns completed. The
constructions of columns 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
b. Earth work
c. Formwork
d. Reinforcement Steel Rebar work.
e. Concrete work
2. Finishing works included:
a. Brick work
b. Plaster work.
c. Painting work
d. Tiling work (Wall & Floor)

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

SMC-Factory No.1/MS-RC 1FL slab

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Factory No. 1
Description:
-

Building purpose : Factory
Foundation
: Spun piles (D300, 350, 400 mm)
Structure
:RC structures + steel rafter; Slab on grade.
Dimensions:
o Factory
 140m long (14x10m); 60 (4x15m) - 69m wide
 Ground Floor (FL. 0.00m); 1st Floor (FL. +7.25m)
 Height : 11.40m
o Utilities area: 2 x (120m long, 4.5m wide).

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GROUND FLOOR PLAN

-

Floor load:
o Factory Ground Floor
o WC Ground Floor
o Stair case
o Storage/Utilities

-

Slab thickness:
o Factory Ground floor slab
: 300 mm thk.
o Storage/Utilities Ground Floor slab : 150 mm thk.
o 1st Floor slab
: 140 mm thk.

-

Area:
o

o

: 40 KN/m2.
: 2 KN/m2.
: 3 KN/m2
: 10 KN/m2

Ground floor
+ Factory area
+ Storage/Utilities area

1st Floor

SMC-Factory No.1/MS-RC 1FL slab

: 9561 m2
: 8400 m2
: 1161 m2
: 9561 m2

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GUTTER

CORRIDOR ZINC ROOF SHEET

DOWN SPOUT

C OR R ID O R ZIN C R OO F SH EET

T .R.BEAM
GFL+13.650

1 / 20

T .O.BEAM
GFL+11.900

1 750

1/ 20

CANOPY; STEEL BEAM

F AC TO R Y -02

1FL
GFL+7.250
1 3650

C ON N E C T ION
C OR R ID OR

4 650

STEEL KICKER

GFL
GFL±0

4 800

4800

7 250

9 500

1 1600

LOADING BAY

GUARD POST ( 100?, H=1500)
4 500

1 5000

1 5000

1 5000
6 0000

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1 5000

4 500

1 2000


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TYPICAL CROSS SECTION

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3. ORGANIZATION CHART
3.1. Organization Chart (Factory No.1)
Project Manager
NGUYỄN VĂN TRUNG (MP: 090 330 7742)


Site Manager
NGUYỄN HOÀNG TRINH (MP: 090 2911235)


Deputy Site Manager 1

Deputy Site Manager 2

VÕ CÔNG HIẾU (MP: 01676211311)

LƯƠNG VĂN LƯỢNG (MP: 093 734 3055)





Site Engineers

QA&QC

Nguyễn Minh Tuấn (MP: 098 314 5069)

Trần Văn Nghiệp (MP: 090 935 6020)


Nguyễn Văn Hào (MP: 0938.722.730)

Shop Drawings
Hoàng Văn Hải (MP:908 818 1059)

Safety Supervisors

Nguyễn Anh Đức (MP:0986 274 758)

Đỗ Vũ Quyền Anh (MP:090 853 1908)

Construction teams
An An Company
Phương Phương Việt Company

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3.2. Assignment
Position
Deputy Site manager
Site Engineer
QA&QC Engineer
Safety Supervision

Factory No.1
VÕ CÔNG HIẾU

Factory No.9
TRẦN AN TOÀN

NGUYỄN MINH TUẤN
NGUYỄN VĂN HÀO
TRẦN VĂN NGHIỆP
ĐỖ VŨ QUYỀN ANH

LÊ VĂN TUẤT
BÙI CÔNG HUYNH
BÙI THANH HẢI
PHẠM VĂN MẠNH

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.

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6. SCOPE OF WORKS:
The 1FL suspended slab include main area 140m long x 60m wide and the sub-area along grid A & E.
The finished level of slab mostly is +7.250 (m) from the Ground floor. Some areas have the finished levels at
-0.05 or -0.15m (in compared with 1FL).
The RC members are listed as below:
DIMENSION

BEAM

SLAB

MEMBER LIST
MARK
1B1, 1B5A; 1B7
1B2; 1B3; 1B4; 1B2A; 1B2B;
1B4A; 1B3A; 1B3B; 1B8; 1B9
1B5; 1B6; 1B5B; 1B6A
1S1
1S2
1S3
1S4
1S5

The RC beams are divided into:
Main beams: supported directly on columns
Secondary beams: supported on main beams.

7. FLOW CHART AND DIRECTION OF WORK

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SIZE (MM)
300 x700
400 x 1100

NOTE
RC
RC

300 x 1100
140
140
140
140
140

RC
RC –S.P.S
RC –S.P.S
RC –S.P.S
RC –S.P.S
RC –S.P.S


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The work sequence of construction the RC 1FL slab is shown at the following flow chart.

Columns underneath suspended slab
Previous stage
Casting lean concrete of ground slab

Installation scaffolding & supports

Formwork fabrication

Installation formwork

Rebar fabrication

Installation of steel rebar

MEP conduits embedment (by others)

Install rails for leveling

Final cleaning

Casting concrete

Curing concrete

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8. PREPARATION WORKS
-

Scaffolding preparation:
+ Scaffolding will be installed aside the and be propped/braced securely.

+ Install platform and handrail on each story of scaffolding.
+ Provide the ladder on scaffolding from the ground to the working level.

-

Surface preparation
+ Chip out and remove all debris, loose material on top surface of s.
+ Cleaning the surface on the top of s 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 1FL s, 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 determined in Technical Specification for each kind of structures. The concrete proportion

is proposed for one mix as below:
Cement
Sand
Fine stone (dmax=10mm)
Water

-

: 50 kg
: 49 liter
: 99 liter
: 22.8 liter

Concrete work
+ Cover starter rebar of s by PVC sheet before casting.
+ Prepare the location for concrete pump.
+ Order the concrete.

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9. CONSTRUCTION METHOD
9.1. Installation scaffolding & support:
-

The scaffoldings for support are divided into two kind:
o For beams: using steel supports 1.0 x 1.0 (m), included 4 props of D49 segment 2.5+ 2.5
+ 1.0 (m) bracing with D42 steel pipes and their accessories such as base/top jack. These
steel supports are braced together with D49 steel pipes and clamps.
o For slab: using scaffolding 1.25 x 1.50 (m), mostly included 5 layers: 4x 1.5 + 0.9 (m),
which are continuously connected together.

Typical layout of scaffolding for beams and slab is shown as below:

Support of Beams

Support of Slab

All scaffoldings/ supports will be installed on base jacks directly placed on lean concrete of ground
floor. The supports of beams and slab are also braced together by using D49 steel pipes and clamps to form a
secure system.

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See attached drawings for more details.

9.2. Installation of formwork
-

Before any use, all the plywood surface will be applied the release agent.
The elevations of beam bottom and slab will varies depend as designed. See attached drawings
for more detail.
Formworks of the beam shall be installed first. Gridline will be clearly marked on the top of s.
Beam formworks will be made by plywood and supported by rectangular steel box 40 x 80 mm for
side and bottom of the beam.

SMC-Factory No.1/MS-RC 1FL slab

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SMC-Factory No.1/MS-RC 1FL slab

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-

Tie rods will also be used through PVC pipes which have a diameter of 10mm to bear the lateral
pressure of concrete. After casting concrete and take out formwork, this hole from PVC pipe will
be treated and filled with mortar. See typical detail below.

-

Formworks of the slab shall be installed next. The secondary girders, steel boxes 2(4x8) cm are
placed on top of scaffolding along the number grid lines. The primary girders- steel boxes 8x4
(cm) will be placed directly under plywood at distance 400 mm. See typical detail below.

9.3. Installation of steel bars
-

-

Fabrication and Installation of rebar shall be done according to the approved working drawing
and project specification. This will also carry out considering the specified splicing length, splicing
location and standard concrete cover.
Slab rebar or stirrups spacing will also be marked particularly the design spacing. Rebar will be
installed based on the design layout. Concrete or mortar blocks will be used as spacer for side in
order to keep the appropriate concrete covering.

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-

-

Beams reinforcement consists of main rebar and stirrups will be assembled first. Concrete spacer
will be placed both sides of beams and bottom to get appropriate concrete cover.
Then slab reinforcement bars (bottom and top layers) will be installed next. Concrete spacer will

be placed at the bottom layer of slab. The top layer of slab will be supported with steel chair to
get appropriate concrete covering.
At intersection of main and secondary beams, the top bars (of main beam) and bottom bars (of
secondary beams will be cranked to maintain the design concrete covers as illustrated below.
Top bar of Main beam to be cranked

Bottom bar of Secondary beam to be cranked

Main beam

Secondary beam

9.4. Concrete work
-

-

a. Construction joint:
The construction joints will be determined at middle span of main beams, e.g. 5,0m from the
numeric gridlines.

The formwork of construction joints are made of steel boxes 2x4, 4x8 (cm) or plywood as
illustrated below. The construction jonts will be reinforced with D10@200 for slab as instructed
by Designer.

SMC-Factory No.1/MS-RC 1FL slab

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-

The construction joints then will be cut at 2cm deep to straighten them before next adjacent cast.
b. Casting sequence:
The 1FL slab will be cast during 13 courses. 1 ST cast will start from area of grid 15-14 then
continue to the end at grid 1. The layout and sequence of casting concrete as below.

-

Concrete will be transported from batching plant to site by mixer truck, the slump of concrete
must be within 12 ± 2.0 (cm).
Ready mixed concrete from mixer truck will be then discharge to concrete pump which is set-up
near the construction area how its boom can reach to the casting slab.

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-

Concrete will be cast from a corner of slab to the opposite corner generally with two steps:

1/ Beams will be cast first and well vibrated. Only the beams in the zone of casting will be cast to avoid

waiting time longer than set time of concrete.

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2/ Continue pour concrete of slab.

c. Leveling concrete surface:
Concrete finishing level will be permanently controlled by rails installed along casting direction. Using
spreading vibrator and straight bar to spread and level the concrete.
The rails are made from D20 steel pipes placed on top of the adjusting support D10. The rails are placed along
sides of each cast area at interval 3.7m to suit with length of screeding vibrator. These supports will stand on
concrete blocks, which are fixed to formwork plywood with nails and tie wire at interval 0.6m. After removal
of formwork, these nails will be cut off.

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3/ Troweling by machine will be carried out to get smooth surface after 2-3 hours.
-

d. Curing:
The concrete will be cured with water during 7 days.
Formwork system will be removed when test result of concrete reach to 80% of designed
strength, side formwork will be removing after 1 day from finished time casting concrete.

SMC-Factory No.1/MS-RC 1FL slab

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10. TOOL & EQUIPMENT
The equipment to be used for the construction of s is listed below.
Item

Description

Unit

Q’ty

Remarks

Equipment
Steel support D49, L=2.5m

With joint

pcs

3500

For beams support

Steel support D49, L=2.5m

Without joint

pcs

3500

For beams support

Steel support D49, L=1.0m
Joint D49

Without joint

pcs
pcs

For beams support
For beams support

Bracing D42, L=1.0m

pcs

Base jack D42, 500mm long
Top jack D42, 500mm long
Platform (360x1000)mm
Scaffolding frame H=1.5m
Scaffolding frame H=0.9m
Scaffolding bracing

pcs
pcs
pcs
pcs
pcs
pcs

Top jack D34

pcs

Steel pipe D49, L=6m
Steel pipe D49, L=3m
Steel pipe D49, L=0.5m

pcs
pcs
pcs

3500
3500

2400
0
3500
3500
200
4300
1080
5500
2100
0
2000
250
7200

Steel boxes 4x8 (cm), L=1.5m

pcs

5000

Steel boxes 4x8 (cm), L=3.0m

pcs

1250
0

Steel boxes 4x8 (cm), L=6.0m

pcs

5000

Yoke 2(5x5) cm, L=1.2m

pcs

2600

Tie rod D12, L=0.8m

pcs

3600

With nuts & washers

Tie rod D16, L=0.8m

pcs

1800

With nuts

Plastic cone, D20/40

pcs

7200

Scaffolding ladder

pcs

80

Scaffolding platform 400x1500

pcs

100

1.22 x 2.44 (m)

pcs

3620

Boom 45m long

ea.
nos
Nos
Nos
.
nos

2
2

4

Plywood 18mm

For beams support
For beams support
For beams support
For beams support
For slab support
For slab support

Machines
Concrete pump
Spreading vibrator, L=4.0m
Concrete Vibrator

Gasoline

Hammer machine
Trowel machine
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1
4

Pumping concrete
Vibrate concrete
For roughening

surface

concrete


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Portable steel cutter
Straightening machine

Nos
Nos

2
1

Cutting machine
Welding machine
Bending machine
Hack-sawing machine
Screwdriver /Drilling machine
Level machine
Theodolite

Nos
Nos
Nos
Nos
Nos
Nos

Nos

2
8
2
4
6
1
1

For cutting steel bar
Use for reinforcing steel work
Diameter <8mm
Use for reinforcing steel work
Use for reinforcing formwork
Use for reinforcing steel work
Manufacturing formwork
Manufacturing formwork
Control the elevation
Locate the gridline

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:
-

Plywood, 18mm thk. reinforced with steel boxes 40 x 80 x 2.0 (mm)
Wooden strip to form chamfer 15x15 (mm).

d/ Curing agent:
-

SIKA Antisol-S.

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.

-

Steel rebar:
Delivered reinforcement bars are to be stored in stockyard nearby fabrication shop for
convenient moving to the shop for cutting and bending.

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Fabricated bars will be separately stored in the next area in the fabrication yard with tagged
bundles to avoiding steel scraps mix-up.
Steel bars are stored on the steel platform or concrete blocks to prevent the contact of steel
rebar with the ground. All steel rebar are stocked in the steel yard with roofing and cover with
plastic sheet to protect them with rain water.
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.

-

Installation of rebar
+ Checking material: certificate, check dimension by caliper, take the sample for checking
physical-mechanical.
+ Check the length, number, position, anchor length, joint by visual and ruler.
+ Thickness of protection: checking by tape
+ Lap length: Rebar SD390 Ribbed bar: 40d (tensile), 15d (compressive)
The tolerance of works related to beams & slab will comply with KOA ITP shown in Appendix 4.

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