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SEBGL - ST4

GUIDELINES

ON

LONG FIRST MAINTENANCE PERIOD

CORROSION PROTECTION SYSTEMS

FOR STRUCTURAL STEELWORK

A COST COMPARISON

Structural Engineering Branch, ArchSD Page 1 of 28 19 - 1 -Page 1of 28

File code : ST-4.doc

Guidelines on Long First Maintenance Period CorrosionProtection Systems

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Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009

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STRUCTURAL ENGINEERING BRANCH

ARCHITECTURAL SERVICES DEPARTMENT

January 2009 (Revised)




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Content

Content Page

1. Introduction . 3

2. Classification of Environment ... 3

3. Life of Coating . 4

4. Choices for Long First Maintenance Systems .. 5

5. Cost Comparison between Type C or D painting System and Hot-Dip Galvanizing

Systems (including Type F Painting System) 6

6. Recommendation .10

7. References 11

Appendix Detailed Cost Comparison for Steel Sections of Blast-Cleaning Followed by

Type C or D Painting System and Hot-Dip Galvanizing Followed by Type F

Painting System




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1. Introduction

The protection of structural steelwork against corrosion can be achieved by many

methods. The selection of a protective system, however, involves qualitative

judgement on the relative importance of many factors that can vary widely according

to the type of structure, its function, its general location, its immediate environment,

and the required life to first maintenance. Cost, needless to say, also plays an

important part in the selection. BS EN ISO 12944 andBS EN ISO 14713 (partially

superseding BS 5493: 1977) has provided guidelines on the choices. The ArchSD

General Specification for Building 2007(the G.SS. for Building (2007)) Table 15.7

also suggests some systems for selection. In the selection of a protective system, the

specifier should consider the environments of the steel structure and the

durability required of the painting system for the first major maintenance of the

painting.

2. Classification of Environment

According to BS EN ISO 12944-2, atmospheric environments are classified as six

atmospheric-corrosivity categories (Table 1):




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Table 1 Classification of Corrosivity Category

Corrosivity

category

Degree of

corrosivity

Examples of typical environments

Exterior Interior

C1 very low----

Heated buildings with

clean atmosphere, e.g.

offices, schools

C2 low

Atmospheres with low

level of pollution.

Mostly rural areas

Unheated buildings where

condensation may occur,

e.g. depots, sports halls

C3 medium

Urban and industrial

atmospheres, moderate

sulfur dioxide

pollution. Coastal areas

with low salinity

Production rooms with

high humidity and some

air pollution, e.g. food-

processing plants,

laundries

C4 high

Industrial areas and

coastal areas with

moderate salinity

Chemical plants,

swimming pools, coastal

ship and boatyards

C5-Ivery high

(industrial)

Industrial areas with

high humidity and

aggressive atmosphere

Buildings or areas with

almost permanent

condensation and with

high pollution

C5-M very high(marine)

Coastal and offshoreareas with high salinity

Buildings or areas with

almost permanentcondensation and with

high pollution

(Source: Adapted fromBS EN ISO12944 2andBS EN ISO 14713)

3. Life of Coating

According to BS EN ISO 12944 and BS EN ISO 14713ISO 12944, the life or

durability of coating is considered as the time which can elapse before the first

major or general maintenance of the coating becomes necessary, or is more

commonly known as the Life to First Maintenance. Experience shows that Type A

painting to Table 15.7 of the G.S. for Building (2007), the life of the painting can

achieve about 2 to 3 years in the environment of Hong Kong, whereas it will be about

5 years for Type B painting.




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For Type C, D painting systems to Table 15.7 of the for Building (2007) and hot-dip

galvanizing without painting system, Type C, D painting systems and hot-dip

galvanizing with or without painting (Type F) are expected to have a long period of

first maintenance period for about 10 to 15 years even for C3 or C4 environment in

Hong Kong.Corus (2004) predicted the Life to First Maintenance based on their own

practical experience and the corrosion rates given in BS EN ISO 12944 and BS EN

ISO 14713, and their prediction is shown in Table 2:

Table 2 Anticipated Life of First Maintenance

with Different Corrosion Protection Systems

Corrosion Protection Systems Corrosivity category Life to First Maintenance

Type C Painting SystemC3 20 years

C4 15 years

Type D Painting SystemC3 25 years

C4 15-20 years

Hot-dip galvanizing (min

85m) without painting

system

C3 40 years

C4 30 years

( BS EN ISO 1461 specifies the standard hot-dip galvanized coating to be 85m

for steel 6mm thick or more, and that thinner steel has thinner coatings.)

However, it is considered that the prediction by Corus (2004) is generally on the

high side, and our experience notes that Type C, D painting systems and hot-dip

galvanizing with or without Type F painting system are expected to have a first

maintenance period for about 10 to 15 years for C3 or C4 environment in Hong Kong.

According toBS EN ISO 12944 andBS EN ISO 14713, the life or durability of

coating is considered as the time which can elapse before the first major or general

maintenance of the coating becomes necessary, or is more commonly known as the

Life to First Maintenance. Experience shows that Type A painting to Table 15.7 of

the GS for Building (2007), the life of the painting can achieve about 2 to 3 years in

the environment of Hong Kong, whereas it will be about 5 years for Type B painting.

And our experience notes that Type C, D painting systems and hot-dip galvanizing




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with or without Type F painting system are expected to have a first maintenance

period for about 15 years for C3 or C4 environment in Hong Kong.

4. Choices for Long First Maintenance Systems

4.1 For the Long First Maintenance Systems (i.e. 10-about 15 years), if in accordance

with the G.S. for Building (2007), the choice in effect is between blast-cleaning

followed by Type C (or D) painting systems and hot-dip galvanizing (with or

withoutor Type F orand G painting systems). The factors that have to be taken into

account for a choice include :-

(a) cCost.

(b) eEaste of control for quality.

(c) pPerformance.

4.2 From experience of the past ArchSD projects, the hot-dip galvanizing is generally

easier to be used as long as the galvanizer is a well-established one; the difficult areas

are only at fasteners and welded joints. Though hot-dip galvanized bolts and nuts are

now readily available in Hong Kong, electro-plated fasteners are sometimes

mistakenly used. It should be noted that electroplated bolts can corrode quickly within

a few years. Therefore, hot-dip galvanized fasteners should always be used for long

first maintenance protective system. PSE should brief the site staff to check the

fasteners delivered to site.

4.3 Type C or D painting systems in Table 15.7 of the GS for Building (2007) are in line

with the painting systems A3.11, A4.14 or A4.15 ofBS EN ISO 12944, which can

achieve 10 toabout 15 years first maintenance period for C3 or C4 environment.

These systems are also in line with recommendation of the superseded BS 5493 in

that systems SK3 and SL6 were suggested to provide for exterior exposed polluted

inland.




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4.4 However, Type C (or D) painting systems, since it requires labour for blast cleaning

and painting, demands more supervision and more control on workmanship. Further

discussion on the choice of the corrosion protection system for different first

maintenance can be found in SEB Guidelines ST3: Notes on Protective Coating of

Steel Structures Against Corrosion.

4.5 The following sectionparagraph will compare the cost between blast-cleaning

followed by Type C or to D painting systems and hot-dip galvanizing (with or

withoutincluding Type F painting system).

5. Cost Comparison between Type C toor D Painting Systems and Hot-Dip

Galvanizing Systems (including Type F Painting System)

5.1 In 1994, this set of Guidelines was first issued to compare the cost of providing

corrosion protection between the then Type C painting system (now Type C and D

painting systems) and hot-dip galvanizing (including Type F painting system). At

that time, extensive surveys of the paint manufacturers and/or suppliers had been

conducted to obtain the then market price for the above corrosion protection systems.

It was found that the cost blast-cleaning followed by Types C or D painting system

was $120/m2, whilst the cost of galvanizing was $4/kg plus the cost of Type F

painting system at $32/m2. With such data, the Guidelines in 1994 concluded that

hot-dip galvanizing (including Type F painting system) became more cost-effective

solution for steel sections with surface area greater than 33m2 per tonne.

5.1 Painting Systems

Type C to D painting systems in Table 15.7 of the G.S. for Building (2007) are in line

with the painting systems A3.11, A4.14 or A4.15 ofBS EN ISO 12944, which can

achieve 10 to 15 years first maintenance period for C3 or C4 environment. These

systems are also in line with recommendation of partially superseded BS 5493 in

that systems SK3 and SL6 were suggested to provide for exterior exposed polluted

inland.

5.22 Unit Cost of Painting




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In 1994, this Guidelines was first issued to compare the cost of providing corrosion

protection between the then Type C painting system (now Type C to D painting

systems) and hot-dip galvanizing (including Type F painting system). At that time,

extensive surveys of the paint manufacturers and/or suppliers had been conducted to

obtain the then market price for the above corrosion protection systems. It was found

that the cost of Types C to D painting system was $120/m2, whilst the cost of

galvanizing was $4/kg plus the cost of Type F painting system at $32/m2. With such

data, the Guidelines in 1994 concluded that hot-dip galvanizing (including Type F

painting system became more cost-effective solution for steel sections with surface

area greater than 33m2 per tonne.

5.2.2 For the purpose of this revision, this Guidelinesset of Guidelines has conducted

another survey in November 2008 on the current market price for the above items.

Four suppliers and/or contractors have been consulted, and the current prices for

blast-cleaning followed by Type C or D painting system are as follows:

Grit blasting to Sa 2 $36.5/m

Cost of paint (including wastage) $84.0/m

Labour $35.0/m

Allow for 15% profit $14.5/m

___________

Total $170/m

5.33 Cost of Hot-Dip Galvanizing




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The market price for hot-dip galvanizing to BS EN ISO 1461 is $3.0/kg

($3000/tonne).

5.44 Cost of Painting to Galvanized Steel

Type F painting system surface involves applying British Rail T-Wash to the

galvanized surface followed by two coats of finishing paint with a dry film thickness

of 80 m. The market price of such painting system is:

Cost : T-Wash + Painting = $38.5/m

Labour = $35.0/m

Profit = $6.5/m

___________

Total $80/m

5.55 Comparison of Cost of Protection for Long Life

5.5.1 The cost of comparison between blast-cleaning followed by Type C orto D painting

systems and hot-dip galvanizing (including Type F painting system) is attached in

Appendix. The results are summarised in Figures 1.

Structural Engineering Branch, ArchSD Page 10 of 28 1 9 - 10 -Page10 of 28



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SurfaceArea = 18 SurfaceArea = 33

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Figure 1 Cost Comparison between Painting and

Hot-Dip Galvanizing

5.5.2 Figures 1 shows that the cost of protection differs depending on the surface area per

unit tonne of section. For heavy section, i.e. less surface areas per tonne, less painting

will be required thus the painting cost is less. On the other handHowever, , the costof galvanizing is relatively constant irrespective the less surface area.

Two break-even points can therefore be found at surface area of 18m/tonne and 33

m/tonne. The two breakeven points indicate that:

(i) for section where the surface area is more than 18 m/tonne, blast-

cleaning followed by Type C or D painting system is more cost

effective than hot-dip galvanizing (without any painting system); and

(ii) for section where the surface area is more than 33 m/tonne, It is found

that blast-cleaning followed by Type C or D painting system is more

cost effective than hot-dip galvanizing (including Type F painting

system). in general except for light section where the surface area is

more than 33 m/tonne.




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5.5.3 The following examples for UC, UB, channel, angle, CHS, SHS and RHS are chosen

for comparison. They have been chosen as representatives for light-, medium- and

heavy-weight members of ..each section.




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For example :-

Area (m ) /tonne) Paint ing - Galva nizing Gal+

Painting

- Gal. +

/Tonne ing nize UC

($ Per tonne of Section)

152 x 152 x 37 kg/m 24.70 4199 3000 4976

254x254x89 kg/m 16.90 2873 3000 4352

305x305x158 kg/m 11.60 1972 3000 3928Pating

UB ($ Per tonne of Section)

203 x 133 x 3025 kg/m 36.400.80 61885236 3000 5912464

356 x 127 x 39 kg/m 30.20 5134 3000 5416

457 x 152 x 82 kg/m 18.40 3128 3000 4472

UC

152 x 152 x 37 kg/m 24.70 4199 3000 4976

254x254x89 kg/m 16.90 2873 3000 4352

305x305x158 kg/m 11.60 1972 3000 3928

Channel s

102 x 51 x 10.42 kg/m 36.30 6171 3000 5904

127 x 64 x 14.90 kg/m 32.00 5440 3000 5760

152 x 89 x 23.84 kg/m 26.00 4420 3000 5080

Angle s

65 x 65 x 4 mm 67.36 11451 3000 8389

1200 x 1200 x 108 mm 34.3627.62 58414695 3000 57845209

225 x 225 x 15 mm 18.15 3085 3000 4452

CHS




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26.9x3.2mm 35.5 6035 3000 584088.9x3.2 mm 32.40 5508 3000 5592

88.9x3.2 mm 32.40 5508 3000 5592193.7x5.0 mm 20.6 3502 3000 4648

457x8.0mm 12.8 2176 3000 4024

SHS

90x90x3.6kg/m 36.30 6171 3000 5904

140x140x5.0 kg/m 26.00 4420 3000 5080

300x300x6.3 kg/m 20.40 3468 3000 4632

RHS

100x50x3.0mm 43.50 7395 3000 6480

200x100x5.0 mm 26.00 4420 3000 5080

450x250x8.0mm 16.20 2754 3000 4296

6. Recommendations

6.1 For 10-about 115 years first maintenance period, it is recommended that :-

Use hot-dip galvanize if surface area 18m per tonne of Section.

(a). If no painting to the finished galvanized surfaces is required and

without too much touch up to welded areas is required, use hot-dip galvanizing

if surface area 18m per tonne of section.

(b). If aesthetic is an important consideration and that painting is required, use Type

C or D painting system if surface area Use blast-cleaning followed by Type C

painting or equivalent if surface area < 33 m per tonne of sSection, and

hot-dip galvanizing +followed by Type F painting system when surface area >

33 m per tonne of section.




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If no painting to the finished galvanized surfaces is required, use hot-dip

galvanizing if surface area 18m per tonne of section.

6.2 With this rule, most structural framework using universal beams and columns is to be

protected by painting, and hot-dip galvanizing is for lightweight framework or lattice

girders assembled by angles or channels or where additional painting is not required

to the finished galvanized surfaces. For longer period of protection (e.g. 20 years or

more), hot-dip galvanizing to more than 140 micron or sprayed zinc will be required;

on thisBS EN ISO 12944 andBS EN ISO 14713 provides more information.

6.3 However, the above rule is not rigid and consideration should be given to the

particular situation of each project, e.g. type of structure, function, general and

immediate environment and the staff requirement for supervision.

In the earlier section, it has been stated that the hot-dip galvanizing is generally

easier to be used as long as the galvanizer is a well-established one; the difficult areas

are only at fasteners and welded joints. Hence, if the cost of hot-dip galvanizing is

marginally (say 10%) higher than the cost of blast-cleaning followed by Type C or D

panting system, PSE may prefer to choose hot-dip galvanizing instead. PSE should

also make judgement on the combination of the sections used with different m2/tonne,

eg. in the case of trusses with combination of I-beams, angles and channels.

7. References

British Standard Institution (1977), Code of Practice for Protective Coating of Ironand Steel Structures Against Corrosion (London: BSI).

British Standard Institution (1998), BS EN ISO 12944-1: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 1: Part 1:

General Introduction (London:, BSI).




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British Standard Institution (1998), BS EN ISO 12944-2: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 2:

Classification of Environments (London:, BSI).

British Standard Institution (1998), BS EN ISO 12944-3: Paints and Varnishes -

Corrosion Protection of Steel Structures by Protective Paint Systems - Part 3: DesignConsiderations (London:, BSI).

British Standard Institution (1998), BS EN ISO 12944-4: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 4: Types

of Surface and Surface Preparation (London:, BSI).


Protective Paint Systems (London:, BSI).


Laboratory Performance Test Methods (London:, BSI).


Execution and Supervision of Paintwork(London:, BSI).

British Standard Institution (1998), BS ENISO 12944-8: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 8:

Development of Specifications for New Work and Maintenance (London:, BSI).

British Standard Institution (1999), BS EN ISO 1461: Hot Dip Galvanized Coatingson Fabricated Iron and Steel Articles Specification (London: BSI).Corus (2004), A Corrosion Protection Guide for Steelwork Exposed to Atmospheric

Environments (Scunthorpe: Corus Construction & Industrial) (Available:

http://www.corusconstruction.com , Accessed: 2 January 2009).

British Standard Institution (1999),BS EN ISO14713: Protection Against Corrosionof Iron and Steel in Structures Zinc and Aluminium Coatings - Guidelines (London:BSI).




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Appendix

Detailed Cost Comparison for Steel Sections of Blast-Cleaning Followed by Type C

or D Painting System and Hot-Dip Galvanizing Followed by Type F Painting System




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UC

SectionSurface

Area /tonneCost Comparison of Different Protection ($ / ton of section)

mm (m2 /ton) Painting Galvanize only Gal+Painting

356 x 406 x634

3.98 HK$676.60 HK$3,000.0 HK$3,318.40 356 x 406 x551

4.49 HK$763.30 HK$3,000.0 HK$3,359.20 356 x 406 x467

5.19 HK$882.30 HK$3,000.0 HK$3,415.20 356 x 406 x393

6.05 HK$1,028.50 HK$1,077.07 HK$3,000.0 HK$3,484.00 HK$3,506.86

356 x 406 x340

6.90 HK$1,173.00 HK$3,000.0 HK$3,552.00 356 x 406 x287

8.05 HK$1,368.50 HK$3,000.0 HK$3,644.00 356 x 406 x235

9.69 HK$1,647.30 HK$3,000.0 HK$3,775.20 356 x 368 x202

10.80 HK$1,836.00 HK$3,000.0 HK$3,864.00 356 x 368 x177

12.30 HK$2,091.00 HK$3,000.0 HK$3,984.00 356 x 368 x153

14.10 HK$2,397.00 HK$2,286.50 HK$3,000.0 HK$4,128.00 HK$4,076.00

356 x 368 x129

16.60 HK$2,822.00 HK$3,000.0 HK$4,328.00 305 x 305 x283

6.86 HK$1,166.20 HK$3,000.0 HK$3,548.80 305 x 305 x240

7.94 HK$1,349.80 HK$3,000.0 HK$3,635.20 305 x 305 x198

9.46 HK$1,608.20 HK$3,000.0 HK$3,756.80 305 x 305 x158

11.60 HK$1,972.00 HK$2,014.74 HK$3,000.0 HK$3,928.00 HK$3,948.11

305 x 305 x137

13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 305 x 305 x118

15.30 HK$2,601.00 HK$3,000.0 HK$4,224.00 305 x 305 x97

18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 254 x 254 x167

9.45 HK$1,606.50 HK$3,000.0 HK$3,756.00 254 x 254 x132

11.70 HK$1,989.00 HK$3,000.0 HK$3,936.00 254 x 254 x107

14.20 HK$2,414.00 HK$2,470.10 HK$3,000.0 HK$4,136.00 HK$4,162.40

254 x 254 x89

16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 254 x 254 x73

20.40 HK$3,468.00 HK$3,000.0 HK$4,632.00 203 x 203 x86

14.40 HK$2,448.00 HK$3,000.0 HK$4,152.00 203 x 203 x71

17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 203 x 203 x60

20.10 HK$3,417.00 HK$3,417.00 HK$3,000.0 HK$4,608.00 HK$4,608.00

203 x 203 x52

23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 203 x 203 x46

25.80 HK$4,386.00 HK$3,000.0 HK$5,064.00 152 x 152 x37

24.70 HK$4,199.00 HK$3,000.0 HK$4,976.00 152 x 152 x30

30.00 HK$5,100.00 HK$5,292.67 HK$3,000.0 HK$5,400.00 HK$5,490.67

152 x 152 x23

38.70 HK$6,579.00 HK$3,000.0 HK$6,096.00

Notes: Cost of blast-cleaning followed by Type C or D painting system is always less than 110% of the costof hot-dip galvanizing followed by Type F painting system,..




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UB

SectionSurface



914 x 419 x388

8.87 HK$1,507.90 HK$3,000.0 HK$3,709.60 914 x 419 x343

9.95 HK$1,691.50 HK$3,000.0 HK$3,796.00 914 x 305 x289

10.40 HK$1,768.00 HK$3,000.0 HK$3,832.00 914 x 305 x253

11.80 HK$2,006.00 HK$1,955.57 HK$3,000.0 HK$3,944.00 HK$3,920.27

914 x 305 x224

13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 914 x 305 x201

14.70 HK$2,499.00 HK$3,000.0 HK$4,176.00 838 x 292 x226

12.40 HK$2,108.00 HK$3,000.0 HK$3,992.00 838 x 292 x194

14.40 HK$2,448.00 HK$2,414.00 HK$3,000.0 HK$4,152.00 HK$4,136.00

838 x 292 x176

15.80 HK$2,686.00 HK$3,000.0 HK$4,264.00 762 x 267 x197

13.00 HK$2,210.00 HK$3,000.0 HK$4,040.00 762 x 267 x173

14.60 HK$2,482.00 HK$3,000.0 HK$4,168.00 762 x 267 x147

17.10 HK$2,907.00 HK$2,694.50 HK$3,000.0 HK$4,368.00 HK$4,268.00

762 x 267 x134

18.70 HK$3,179.00 HK$3,000.0 HK$4,496.00 686 x 254 x170

13.80 HK$2,346.00 HK$3,000.0 HK$4,104.00 686 x 254 x152

15.40 HK$2,618.00 HK$3,000.0 HK$4,232.00 686 x 254 x140

16.60 HK$2,822.00 HK$2,732.75 HK$3,000.0 HK$4,328.00 HK$4,286.00

686 x 254 x125

18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 610 x 305 x238

10.30 HK$1,751.00 HK$3,000.0 HK$3,824.00 610 x 305 x179

13.50 HK$2,295.00 HK$2,255.33 HK$3,000.0 HK$4,080.00 HK$4,061.33

610 x 305 x149

16.00 HK$2,720.00 HK$3,000.0 HK$4,280.00 610 x 229 x140

15.10 HK$2,567.00 HK$3,000.0 HK$4,208.00 610 x 229 x125

16.70 HK$2,839.00 HK$3,000.0 HK$4,336.00 610 x 229 x113

18.40 HK$3,128.00 HK$3,004.75 HK$3,000.0 HK$4,472.00 HK$4,414.00

610 x 229 x101

20.50 HK$3,485.00 HK$3,000.0 HK$4,640.00 533 x 210 x122

15.50 HK$2,635.00 HK$3,000.0 HK$4,240.00 533 x 210 x109

17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 533 x 210 x101

18.50 HK$3,145.00 HK$3,192.60 HK$3,000.0 HK$4,480.00 HK$4,502.40

533 x 210 x92

20.20 HK$3,434.00 HK$3,000.0 HK$4,616.00 533 x 210 x82

22.50 HK$3,825.00 HK$3,000.0 HK$4,800.00 457 x 191 x98

16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 457 x 191 x89

18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 457 x 191 x82

20.10 HK$3,417.00 HK$3,464.60 HK$3,000.0 HK$4,608.00 HK$4,630.40

457 x 191 x74

22.10 HK$3,757.00 HK$3,000.0 HK$4,768.00




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457 x 191 x67

24.30 HK$4,131.00 HK$3,000.0 HK$4,944.00 457 x 152 x82

18.40 HK$3,128.00 HK$3,000.0 HK$4,472.00 457 x 152 x74

20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 457 x 152 x67

22.30 HK$3,791.00 HK$3,879.40 HK$3,000.0 HK$4,784.00 HK$4,825.60

457 x 152 x60

24.90 HK$4,233.00 HK$3,000.0 HK$4,992.00 457 x 152 x52

28.20 HK$4,794.00 HK$3,000.0 HK$5,256.00




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UB (contd)

SectionSurface

Area /tonne

Cost Comparison of Different Protection ($ / ton of section)

mm (m2 /ton) PaintingGalvanize

onlyGal+Painting

406 x 178 x74

20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 406 x 178 x67

22.30 HK$3,791.00 HK$3,000.0 HK$4,784.00 406 x 178 x60

24.80 HK$4,216.00 HK$4,029.00 HK$3,000.0 HK$4,984.00 HK$4,896.00

406 x 178 x54

27.40 HK$4,658.00 HK$3,000.0 HK$5,192.00 406 x 140 x46

29.20 HK$4,964.00 HK$3,000.0 HK$5,336.00 406 x 140 x39

34.20 HK$5,814.00 HK$5,389.00 HK$3,000.0 HK$5,736.00 HK$5,536.00

356 x 171 x

6720.60 HK$3,502.00 HK$3,000.0 HK$4,648.00

356 x 171 x57

24.10 HK$4,097.00 HK$3,000.0 HK$4,928.00 356 x 171 x51

26.70 HK$4,539.00 HK$4,734.50 HK$3,000.0 HK$5,136.00 HK$5,228.00

356 x 171 x45

30.10 HK$5,117.00 HK$3,000.0 HK$5,408.00 356 x 127 x39

30.20 HK$5,134.00 HK$3,000.0 HK$5,416.00 356 x 127 x33

35.40 HK$6,018.00 HK$3,000.0 HK$5,832.00 305 x 165 x54

23.30 HK$3,961.00 HK$3,000.0 HK$4,864.00 305 x 165 x46

27.10 HK$4,607.00 HK$4,601.33 HK$3,000.0 HK$5,168.00 HK$5,165.33

305 x 165 x

4030.80 HK$5,236.00 HK$3,000.0 HK$5,464.00

305 x 127 x48

22.70 HK$3,859.00 HK$3,000.0 HK$4,816.00 305 x 127 x42

25.80 HK$4,386.00 HK$4,391.67 HK$3,000.0 HK$5,064.00 HK$5,066.67

305 x 127 x37

29.00 HK$4,930.00 HK$3,000.0 HK$5,320.00 305 x 102 x33

30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 305 x 102 x28

35.40 HK$6,018.00 HK$6,018.00 HK$3,000.0 HK$5,832.00 HK$5,832.00

305 x 102 x25

40.00 HK$6,800.00 HK$3,000.0 HK$6,200.00 254 x 146 x43

25.10 HK$4,267.00 HK$3,000.0 HK$5,008.00 254 x 146 x

37 29.00 HK$4,930.00 HK$5,003.67 HK$3,000.0 HK$5,320.00 HK$5,354.67254 x 146 x31

34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 254 x 102 x28

31.90 HK$5,423.00 HK$3,000.0 HK$5,552.00 254 x 102 x25

35.60 HK$6,052.00 HK$6,120.00 HK$3,000.0 HK$5,848.00 HK$5,880.00

254 x 102 x22

40.50 HK$6,885.00 HK$3,000.0 HK$6,240.00 203 x 133 x30

30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 203 x 133 x25

36.40 HK$6,188.00 HK$5,712.00 HK$3,000.0 HK$5,912.00 HK$5,688.00

203 x 102 x23

34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 178 x 102 x19 38.80 HK$6,596.00 HK$3,000.0 HK$6,104.00 152 x 89 x 16 39.80 HK$6,766.00 HK$3,000.0 HK$6,184.00 Structural Engineering Branch, ArchSD Page 23 of 28 1 9 - 23 -Page

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127 x 76 x 13 41.30 HK$7,021.00 HK$3,000.0 HK$6,304.00 203 x 133 x30

30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 203 x 133 x25

36.40 HK$6,188.00 HK$5,712.00 HK$3,000.0 HK$5,912.00 HK$5,688.00

203 x 102 x23

34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 178 x 102 x19 38.80 HK$6,596.00 HK$3,000.0 HK$6,104.00 152 x 89 x 16 39.80 HK$6,766.00 HK$3,000.0 HK$6,184.00 127 x 76 x 13 41.30 HK$7,021.00 HK$3,000.0 HK$6,304.00

UC

SectionSurface



356 x 406 x634

3.98 HK$676.60 HK$3,000.0 HK$3,318.40 356 x 406 x551

4.49 HK$763.30 HK$3,000.0 HK$3,359.20 356 x 406 x467

5.19 HK$882.30 HK$3,000.0 HK$3,415.20 356 x 406 x393

6.05 HK$1,028.50 HK$1,077.07 HK$3,000.0 HK$3,484.00 HK$3,506.86

356 x 406 x340

6.90 HK$1,173.00 HK$3,000.0 HK$3,552.00 356 x 406 x287 8.05 HK$1,368.50 HK$3,000.0 HK$3,644.00 356 x 406 x235

9.69 HK$1,647.30 HK$3,000.0 HK$3,775.20 356 x 368 x202

10.80 HK$1,836.00 HK$3,000.0 HK$3,864.00 356 x 368 x177

12.30 HK$2,091.00 HK$3,000.0 HK$3,984.00 356 x 368 x153

14.10 HK$2,397.00 HK$2,286.50 HK$3,000.0 HK$4,128.00 HK$4,076.00

356 x 368 x129

16.60 HK$2,822.00 HK$3,000.0 HK$4,328.00 305 x 305 x283

6.86 HK$1,166.20 HK$3,000.0 HK$3,548.80 305 x 305 x240

7.94 HK$1,349.80 HK$3,000.0 HK$3,635.20 305 x 305 x198 9.46 HK$1,608.20 HK$3,000.0 HK$3,756.80 305 x 305 x 11.60 HK$1,972.00 HK$2,014.74 HK$3,000.0 HK$3,928.00 HK$3,948.11




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158

305 x 305 x137

13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 305 x 305 x118

15.30 HK$2,601.00 HK$3,000.0 HK$4,224.00 305 x 305 x97

18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 254 x 254 x167 9.45 HK$1,606.50 HK$3,000.0 HK$3,756.00 254 x 254 x132

11.70 HK$1,989.00 HK$3,000.0 HK$3,936.00 254 x 254 x107

14.20 HK$2,414.00 HK$2,470.10 HK$3,000.0 HK$4,136.00 HK$4,162.40

254 x 254 x89

16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 254 x 254 x73

20.40 HK$3,468.00 HK$3,000.0 HK$4,632.00 203 x 203 x86

14.40 HK$2,448.00 HK$3,000.0 HK$4,152.00 203 x 203 x71

17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 203 x 203 x60

20.10 HK$3,417.00 HK$3,417.00 HK$3,000.0 HK$4,608.00 HK$4,608.00

203 x 203 x52 23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 203 x 203 x46

25.80 HK$4,386.00 HK$3,000.0 HK$5,064.00 152 x 152 x37

24.70 HK$4,199.00 HK$3,000.0 HK$4,976.00 152 x 152 x30

30.00 HK$5,100.00 HK$5,292.67 HK$3,000.0 HK$5,400.00 HK$5,490.67

152 x 152 x23

38.70 HK$6,579.00 HK$3,000.0 HK$6,096.00

Remarks: Cost of painting is always less than the cost of gal + painting in this case, and therefore use paintingas corrosion protection system for UC sections is recommended.




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Channel

SectionSurface Area

/tonne

Cost Comparison of Different Protection ($ / ton of section)


432x102 18.60 HK$3,162.00 HK$3,000.0 HK$4,488.00 381x102 20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 305x102 20.90 HK$3,553.00 HK$3,000.0 HK$4,672.00 305x89 22.10 HK$3,757.00 HK$3,000.0 HK$4,768.00 254x89 23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 254x76 27.40 HK$4,658.00 HK$3,000.0 HK$5,192.00 229x89 23.50 HK$3,995.00 HK$3,000.0 HK$4,880.00 229x76 27.80 HK$4,726.00 HK$3,000.0 HK$5,224.00 203x89 24.20 HK$4,114.00 HK$3,000.0 HK$4,936.00 203x76 28.30 HK$4,811.00 HK$3,000.0 HK$5,264.00 178x89 25.00 HK$4,250.00 HK$3,000.0 HK$5,000.00 178x76 30.00 HK$5,100.00 HK$3,000.0 HK$5,400.00 152x89 26.00 HK$4,420.00 HK$3,000.0 HK$5,080.00 152x76 32.20 HK$5,474.00 HK$3,000.0 HK$5,576.00 127x64 32.00 HK$5,440.00 HK$3,000.0 HK$5,560.00 102x51 36.30 HK$6,171.00 HK$3,000.0 HK$5,904.00 76x38 42.10 HK$7,157.00 HK$3,000.0 HK$6,368.00

Angle

SectionSurface Area

/tonneCost Comparison of Different Protection ($ / ton of section)


400x400x21 11.25 HK$1,912.50 HK$3,000.0 HK$3,900.00 350x350x18 14.86 HK$2,526.20 HK$3,000.0 HK$4,188.80 300x300x18 14.06 HK$2,390.20 HK$3,000.0 HK$4,124.80 240x240x15 18.05 HK$3,068.50 HK$3,000.0 HK$4,444.00 225x225x15 18.15 HK$3,085.50 HK$3,000.0 HK$4,452.00 200x200x15 18.26 HK$3,104.20 HK$3,000.0 HK$4,460.80 165x165x10 26.83 HK$4,561.10 HK$3,000.0 HK$5,146.40 120x120x10 27.62 HK$4,695.40 HK$3,000.0 HK$5,209.60 115x115x8 34.07 HK$5,791.90 HK$3,000.0 HK$5,725.60 100x100x8 34.36 HK$5,841.20 HK$3,000.0 HK$5,748.80 90x90x6 45.00 HK$7,650.00 HK$3,000.0 HK$6,600.00 80x80x6 45.45 HK$7,726.50 HK$3,000.0 HK$6,636.00 65x65x4 67.36 HK$11,451.20 HK$3,000.0 HK$8,388.80 60x60x4 67.42 HK$11,461.40 HK$3,000.0 HK$8,393.60 50x50x4 68.97 HK$11,724.90 HK$3,000.0 HK$8,517.60




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CHS

SectionSurface



508x8.0 12.7 HK$2,159.00 HK$3,000.0 HK$4,016.00 457.0x8.0 12.8 HK$2,176.00 HK$3,000.0 HK$4,024.00 406.4x6.3 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 323.9x6.3 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 273.0x5.0 20.4 HK$3,468.00 HK$3,000.0 HK$4,632.00 244.5x12 8.76 HK$1,489.20 HK$3,000.0 HK$3,700.80 219.1x5.0 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 193.7x5.0 20.6 HK$3,502.00 HK$3,000.0 HK$4,648.00 168.3x5.0 20.6 HK$3,502.00 HK$3,000.0 HK$4,648.00 139.7x5.0 20.7 HK$3,519.00 HK$3,000.0 HK$4,656.00 114.3x3.2 32.1 HK$5,457.00 HK$3,000.0 HK$5,568.00 88.9x3.2 32.4 HK$5,508.00 HK$3,000.0 HK$5,592.00 76.1x3.2 32.6 HK$5,542.00 HK$3,000.0 HK$5,608.00 60.3x3.2 32.9 HK$5,593.00 HK$3,000.0 HK$5,632.00 18.3x3.2 33.6 HK$5,712.00 HK$3,000.0 HK$5,688.00 42.4x3.2 33.8 HK$5,746.00 HK$3,000.0 HK$5,704.00 26.9x3.2 35.5 HK$6,035.00 HK$3,000.0 HK$5,840.00

SHS

SectionSurface



400x400x10.0 12.9 HK$2,193.00 HK$3,000.0 HK$4,032.00 350x350x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 300x300x6.3 20.4 HK$3,468.00 HK$3,000.0 HK$4,632.00 250x250x6.3 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 200x200x5.0 25.9 HK$4,403.00 HK$3,000.0 HK$5,072.00 180x180x6.3 20.7 HK$3,519.00 HK$3,000.0 HK$4,656.00 160x160x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 150x150x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 140x140x5.0 26.00 HK$4,420.00 HK$3,000.0 HK$5,080.00 120x120x5.0 26.20 HK$4,454.00 HK$3,000.0 HK$5,096.00 100x100x4.0 32.80 HK$5,576.00 HK$3,000.0 HK$5,624.00 90x90x3.6 36.3 HK$6,171.00 HK$3,000.0 HK$5,904.00 80x80x3.0 36.5 HK$6,205.00 HK$3,000.0 HK$5,920.00 70x70x3.0 36.6 HK$6,222.00 HK$3,000.0 HK$5,928.00 60x60x3.0 43.9 HK$7,463.00 HK$3,000.0 HK$6,512.00 50x50x3.0 44.1 HK$7,497.00 HK$3,000.0 HK$6,528.00 40x40x3.0 44.6 HK$7,582.00 HK$3,000.0 HK$6,568.00




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RHS

SectionSurface



500x300x8.0 16.1 HK$2,737.00 HK$3,000.0 HK$4,288.00 450x250x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 400x200x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 300x200x6.3 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 300x100x8.0 16.3 HK$2,771.00 HK$3,000.0 HK$4,304.00 250x150x5.0 25.9 HK$4,403.00 HK$3,000.0 HK$5,072.00 250x100x10 13.2 HK$2,244.00 HK$3,000.0 HK$4,056.00 200x150x8.0 16.4 HK$2,788.00 HK$3,000.0 HK$4,312.00 200x120x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 200x100x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 160x80x4.0 32.6 HK$5,542.00 HK$3,000.0 HK$5,608.00 150x100x5.0 26.2 HK$4,454.00 HK$3,000.0 HK$5,096.00 120x80x5.0 26.3 HK$4,471.00 HK$3,000.0 HK$5,104.00 120x60x3.6 36.2 HK$6,154.00 HK$3,000.0 HK$5,896.00 100x60x3.6 36.5 HK$6,205.00 HK$3,000.0 HK$5,920.00 100x50x3.0 43.5 HK$7,395.00 HK$3,000.0 HK$6,480.00 90x50x3.6 41.3 HK$7,021.00 HK$3,000.0 HK$6,304.00 80x40x3.2 44.1 HK$7,497.00 HK$3,000.0 HK$6,528.00 60x40x3.0 42.1 HK$7,157.00 HK$3,000.0 HK$6,368.00


Documents

sebgl -st4(6.1.2009)