ATTACHMENT A

STATEMENT OF WORKS TO CARRY OUT REPAIR WORKS AT THE VISA PAVILION

AREA OF THE US CONSULATE LAGOS.

A.1 INTRODUCTION

The Consular section of the US Consulate Lagos intends to carry out repair works on different elements

of the visa Pavilion area, secondly there is need to increase the floor area of the Visa Pavilion to

accommodate additional applicants.

Contractor shall carry out the painting of the entire roof steel trusses, the perimeter fence walls and

other structures at the Pavilion area. The steel trusses will include the one for the additional roof area

introduced to cover the additional slab area to be constructed.

Contractor shall provide the service by carrying out civil works to construct a concrete slab which will be

resting on a new foundation connected to the existing pile/ raft foundation of the pavilion area .

Contractor shall be expected to provide structural details and calculations for additional floor area.

Contractor shall change the roofing sheets at the Pavilion, the new roof shall also cover the extended

concrete slab to be constructed.

The Contractor shall provide all necessary supervision, materials, labor, equipment, tools and

transportation required to perform the works in accordance to dimensions and specification given in the

SOW for reference.

The Work to be covered by the specifications consists of providing all labor, plant, equipment supplies

material handling, transportation and performing all necessary operations to carry out the construction

of the additional floor area to accommodate applicants.

A-2 GENERAL NOTES

A-2-1 All materials needed for the execution of the project unless otherwise stated shall be procured

and installed by the Contractor who shall provide all labor and equipment to perform the above works in

accordance with the technical specifications.

A-2-2 Contractor shall verify the square area which is specified in the SOW.

A-2-3 All debris resulting from the installation works shall be carted away and di sposed at a designated

facility by the Contractor for the debris generated during the works, unless otherwise requested by the

COR. The Contractor shall ensure that by the end of each working day the site shall be cleaned, and

materials shall be kept secured to avoid possible injuries to the Consulate staff.

A-2-4 Normal working hours shall be from 0800 to 1600 from Mondays to Fridays, Saturday work shall

be from 0800 to 1800. All after work hours shall be approved in advance.

A-2-5 All damages resulting from the Contractor's work shall be repaired by the Contractor at his own

expense, the Contractor shall take reasonable precautions not to damage existing structure, materials

and equipment during course of this project.

A-3 SECURITY REQUIREMENTS

A-3-1 The Contractor shall comply and abide to the embassy security regulations and procedures.

A-3-2 The Contractor shall provide the names and copies of identity cards for all technicians, machinery

drivers and laborers working under this contract to the Facility Management office. When the securi ty

clearances are completed (usually two weeks after the submission of information) the Contractor shal l

be notified on project start date. Any addition of the list must allow for necessary security checks before

they can join the project team. All Contractor personnel will be required to submit a photo ID before

receiving an embassy ID badge. The badges must always be worn at all times while on the compound.

No weapons, radios, cameras or tape recorders shall be brought into the compound.

A-3-3 The material, equipment and tools shall be inspected by the Embassy security guards prior to the

admittance to the compound. Trucks with bulky materials will not be allowed access to the compound

except when escorted before and after loading. Otherwise the contractor shall be required to move the

cargo on to the embassy truck and to site using his resources.

A-4 ON SITE SAFETY

A-4-1 Contractor is responsible for meeting all international or occupational safety Hazardous

Administration safety standards (OSHA). The Contractor must provide the name of the person/persons

responsible for on-site safety (the person can be the project manager)

A-4-2 Contractor shall provide a control method document for the works to be executed which wi ll be

submitted to the COR.

A-4-3 Contractor shall provide all personnel protective equipment (PPE - hard hat, safety boots, glasses ,

ear plugs, earmuffs etc.) for all contract employees. All the workers on site shall be dressed properly and

follow the Consulate's safety rules and regulations.

A-4-4 Any delay due to safety violations shall not in any case be compensated by the Consulate.

A-5 CIVIL WORKS DESCRIPTION OF WORKS

A-5-1 Description

The Contractor shall furnish all manpower required machines, technicians, materials and other needed

resources to carry out the job. The contractor shall be required to increase the floor area on the front

and rear elevation of the pavilion. The approximate area of the slab to be extended at the front

elevation is 58m2 while for the rear elevation close to the seaside the approximate floor area to be

extended is 72m2. Total area of slab to be constructed is approximately 130m2. Attached to Statement

of work is the drawing showing the shaded area for the additional floor area.

The Contractor shall to carry out a geotechnical investigation of the intended area, the results

from the soil investigation shall indicate the geological description, sub soil conditions, ground

water conditions, site description and the topography of the site.

The Contractor shall provide Architectural drawings which are to be submitted for approval, the

construction drawings shall show the plan floor of the visa applicant area with the various

sections capturing the areas where the additional slab area is to be introduced.

Contractor shall produce the structural drawings for the construction works showing the type

and depth of foundation, all calculation sheets shall be produced and submitted to the COR.

All excavations carried out shall be carefully down with the aid of backhoe machine, all

excavated materials shall be carted away immediately from site, the area shall be wel l cordoned

off during the excavation, the Contractor shall adjust the area where the foundation works are

to be carried out by leveling the area, compaction shall be carried out with a aid of pneumatic

tire roller having a gross weight of between 10 tones and 12 tones, compacting factor on the

disturbed area shall achieve 90% compaction.

The concrete grade for the foundation and the slab shall be of class C30. Compressive strength

tests for concrete cubes shall be carried out for 7 days and 28 days, the tests shall be carried out

in an approved laboratory by the COR. Contractor shall ensure that the concrete are well

vibrated with the aid of a poker vibrator, this will reduce the possibility of honey combs on the

finished concrete.

The concrete shall be smooth finished in preparation to receive epoxy paints, approximate area

to receive concrete shall be 130m2. Type of epoxy paint to be specified in quote.

The steel hand rails dismantled at the back elevation shall be reinstalled at the end of the newly

constructed slab, the posts shall be bolted to the concrete floor, depth of anchorage to be

approximately 100mm for rigidity, the posts shall be coated with marine gloss paints to reduce

corrosion.

A-6 CONCRETE WORKS SPECFICATIONS

A-6-1. General description

The section covers all concrete works to be provided by the contractor including labor materials

proportioning batching mixing delivering testing receiving placing compacting finishing and working.

The contractor shall inform the Engineer adequately at the times and places which he intends to place

concrete for inspection and approval.

A-6-2 Submittals

At least 21 days prior to start of concrete delivery the following have to be submitted by the contractor

to the Contracting Officer’s Representative (COR) for review

(a) Recommended supplies and source of cement water aggregate and additives including product data

for joint sealants filler

(b) A quality inspector plan

(c) All design mixes for each class of concrete indicating that the concrete ingredients and proportions

will result in the required mix specification

(d) The proposed program methods and details of plant and equipment to be used for batching and

mixing concrete

(e) Test certificate for reinforcement

A-6-3 Delivery storage and handling of material

(a) Aggregate: These shall be transported and stockpiled separately according to their sources and

gradation, they shall be handled in a manner which will prevent segregation and contamination with

foreign materials as contaminated materials will not be used. Muddy or oil leaking equipment shall not

be allowed to operate in stockpiles

(b) Cement: Cement delivered in bags shall be stored in a dry and water proof shed, the bags shall not

be laid directly on the ground to prevent deterioration any bag that contains sumps of hardened cement

shall not be used cement shall be fresh when delivered to site with the manufacturer name brand of

cement and weight written on the bag

(c) Admixtures Dry admixtures shall be in dry well-ventilated housing while liquid admixtures shall be

stored in clean weather height tanks

A-6-4 Quality control

(a) Concrete mix designs

At least 21 days to concrete placement submit proportions for a concrete mix for each strength and type

of concrete required for the structure submittal shall clearly indicate where each mix will be used when

more than one mix design is submitted

(b) Reinforcement

Provide bar bending schedule including lap lengths shapes dimension and concrete cover

(c) Formwork

Indicate arrangement of forms including placement schedules and methods of forming control joints

include locations (if any) conduits and other embedded items

(d) Curing concrete elements

Submit proposed materials and method of curing concrete element

(e) Form work removal schedule

Submit schedule for from removal indicating element and minimum length for striking formwork

provide a full description of materials and methods to be used to patch form tie holes

(f) Concrete placement and compaction

Submit technical literature for equipment and methods proposed for use in placing and compacting

concrete including the description of the equipment in terms of type diameter and length

(g) Field test technician

Submit data on the qualification of proposed testing technicians for approval by the contracting officer

to perform any work

(h) Mix designs

Provide a detailed report of materials and methods used test results for concrete required to meet

durability requirements

(i) Concrete mix proportions

Submit copies of test reports by independent test laboratories showing that the mix has been

successfully tested to produce concrete with the properties specified and that the mix will be suitable

for the job

(j) Aggregates

Submit test results of aggregate quality with ASTM C33 and the combined graduation curve for grading

proposed for use both in work and mix qualification.

(k) Cement

Submit manufacturer’s technical data

A-6-5 Product specifications

In general, all materials shall comply with the requirements of the BS 12 and ASTM The engineer shall be

provided with test results or reports indicating that the materials comply with relevant standards

1. Cement

The cement shall be ordinary Portland cement complying with BS 6599 when the company is in doubt of

the brand and the quality of cement then samples shall be sent to an approved lab at contractor’s

expenses

2. Admixtures and additives

These shall not be used until the engineer approval has been given, they shall comply with BS8110 and

BS 5075 requirements

Chemical admixtures may be water reducing admixture and water reducing and retarding admixtures

3. Water

Water to be used for curing and mixing concrete shall be clean and free from injurious amounts of oil

acid alkali concreting water shall not be used until tested and approved with BS3148 and BS5328 mixing

water for use with cement shall be suitable to ensure that the salts content of the total concrete mix

does not exceed required limitation Mixing water shall not contain more than 500 parts per million of

chlorides as CL ad not more than 100 parts per million of sulphates as so4.

4. Fine aggregate

This shall consist of natural sand composed of clean hard and durable spherical particles in conformity

with British standard institute any physical dirt and mud shall be completely sieved out of sharp sand

before use

5. Coarse aggregate

Coarse aggregate which shall consist of crushed stone shall be clean hard and uncoated particles

laboratory test results report shall prove its compliance with the requirements of BS 812 882 and 8007

specific gravity of aggregate should be a minimum of 2.5 when tested in accordance with AASHTO (T19)

The maximum aggregate size to be used for reinforced concrete shall be 20mm (3/4i nch)

A-6-6 Performance and Design requirements

Classes of concrete: Classes of concrete are denoted by designations which consist of letter fol lowed by

a numeral indicating the 28-day compressive strength in Mega pascal as determined by bs1881 and bs

8110

A-6-7 Concrete mix design criteria

Design concrete mixes shall have a minimum cement per cubic meter of concrete consistent with the

required slump a water content corresponding to the appropriate water cement ratio the maximum

coarse aggregate size and the required grading of aggregates. The design mixes for each class of

concrete shall be as determined by the contractor and acceptable to COR unless otherwise stated

strength requirements shall be based on 28-day compressive strength determined on 150mm cubic

specimens

A-6-8 Sampling and testing

Before use all concrete compounds shall be tested in an approved laboratory acceptable to the COR in

accordance to BS1881

A-6-9 Slump range

This shall be maintained for concrete at point of delivery

A-6-10 Minimum cement content

This shall be specified for each class of concrete

Structural concrete: The concrete shall be class C30/25

A-6-11 Proportioning

Unless specified otherwise the proportion of cement fine and coarse aggregate of the various class of

concrete shall be approved by the COR and may be varied by same

(a) Batching and mixing

Concrete shall be batched and mixed at a central batching and mixing plant. The amount of concrete

mixed in one batch shall not be more that the rated capacity of the mixer batching to be done by

volume,

(b) Mixing

The fine and coarse aggregate and the cement shall be mixed for not less than four turns of the drum

before water is added the concrete shall be mixed until a uniform consistency and color has been

obtained.

(c) Transportation

Concrete shall be so transported and placed that contamination, segregation or loss of the constituent

materials does not occur Concrete shall be compacted in final position within 30 mins from the time of

introduction of the cement into aggregates

The slump of delivered concrete shall be determined on site and shall not exceed the working limits

shown below

Working limit Margin of error Rejection limit

100mm 20mm 120mm

(d) Curing

Concrete shall be prevented from loss of moisture for at least 14 days after placement carrying of

concrete shall be any method which will keep the concrete surfaces adequately wet during the specified

curing period. Precast members should not be placed in seawater before completion of specified curing.

Water curing by saturation of concrete surfaces shall begin as quickly as possible after initial set of the

concrete and shall continue for an initial curing period of 14 days only portable water shall be used for

curing

(e) Field quality control

Field control tests are to be performed according to BSI

1. Aggregate test shall be performed as specified by the engineer and to comply wi th BSI Grading test

acceptable

2. Sampling concrete samples of fresh concrete shall be obtained in the field according to BS1881

3. A slump test shall be made for each 5 to 7m3 of concrete tolerance should not exceed 20mm

4. Water shall be tested as specified by engineer and according to bs 3145 standard

5 Compression tests: One of the six concrete compression test cubes shall be made each that when less

than 10m3 of concrete are place. If quantity placed per day is within 50m3 then two set of six cubes wil l

be taken two cubes of each set shall be tested at 7 days and another two at 28 days, the third two will

be crushed if the 28 days results are odd and need to be verified, compressive test will be evaluated

based on Bs1881.

Concrete mix design standard parameters

Concrete class 28 -day min characteristic comp strength (MPA)

Min cement content (Kg/m3)

Maximum water/cement ratio

Max Slump (mm)

C40 40 400 0.40 150 R.C structure C30 30 360 0.50 100 R.C structure

C25 25 310 0.55 100 Blinding in aggressive soils

C20 20 280 0.55 120 Blinding of fill concrete

C15 15 220 0.6 120 Concrete fill material

A-7 PAINTING WORKS GENERAL DESCRIPTION

A-7-1 Scope

The Contractor shall furnish all manpower, materials to carry out the works. The Contractor shall be

required to apply two coats of approved brand and color by the COR on the surfaces in the following

areas:

The male and female rest rooms external walls.

The concrete fence.

The roof beam trusses. The vertical posts.

The security post external walls. A-7-2 Description

Contractor shall apply paint on all structures which is not limited to the following: all masonry wall, metal posts, trusses etc. Contractor shall scrap off the surfaces of the roof trusses and walls, all corroded surfaces on the roof trusses shall be well treated be application of the paint. The paints and color of the paint to be used shall be approved by the COR. The paints shall be lead-free and non-toxic.

Contractor shall apply two coats of Dulux paints on the external walls of the rest rooms, security post and the perimeter fence while for the roof trusses oil -based paint to be applied. Contractor shall ensure that all surfaces are well prepared before application of the paints, areas where screed work is required should be treated. The Contractor shall protect or remove all fixtures and equipment on the walls during painting works, all equipment and fixtures either removed or protected shall be reinstalled prior to work completion

A-7-3 TECHNICAL SPECIFICATION FOR PAINTING WORKS

a. Exterior Painting

Paint surfaces as directed by the task order. Match paint to similar adjacent materials or surfaces. (1) Paint: This category includes coating systems materials, primers, emulsions, enamels, stains,

sealers and fillers, and other applied materials whether used as prime, intermediate or finish coats.

(2) Product Data: The Contractor shall follow the manufacturer's technical information, label

analysis, and application instructions for each paint material provided for use. The Contractor

shall verify each paint material provided by the USG and cross-reference specific coating and finish system and application to ensure material is suitable for contract work. The Contractor shall verify each material by the manufacturer's catalog number and general classification.

(3) Single Source Responsibility: The Contractor shall verify prior to use that the USG provided

primers and undercoat paint is produced by the same manufacturer as the finish coats in the case that the USG will be procuring the materials.

(4) Material Quality: The Contractor will ensure the USG provide the finest manufacturer's qual i ty

trade sale type paint material for the project and ensure paint material containers display manufacturer's product identification prior to use.

(5) Material Delivery: The USG will provide paint materials to the Contractor who shall del iver USG

provided paint along with Contract provided materials to the job site in manufacturer's original, unopened packages and the containers shall bear the manufacturer's name and label with trade name and manufacturer's instructions.

(6) Material Storage: The Contractor shall store materials not in use in tightly covered containers in

a well-ventilated area at a minimum ambient temperature of 45 degrees F (7 degrees C). The Contractor shall protect materials from excessive heat (temperature above 30 degrees C or 86 degrees F) and keep storage area neat and orderly. Contractor shall remove oily rags and waste daily.

(7) Project Conditions: The Contractor shall not apply paint when the relative humidity exceeds 85

percent, or at temperatures less than 5 degrees F (3 degrees C) above the dew point, or to damp or wet surfaces. The Contractor shall apply paint only in temperatures that comply with the manufacturer's specifications.

(8) Preliminary Examination: The Contractor shall examine substrates and conditions un der which

painting will be performed for compliance with requirements and shall not begin application until unsatisfactory conditions have been corrected.

(9) Preparation:

(a) The Contractor shall remove hardware and hardware accessories, plates, light f ix tures, and items in place that are not to be painted, or provide protection such as taping, prior to surface preparation and painting. (Taping includes lighting fixtures, windows, door jams, etc.)

(b) The Contractor shall remove all old existing paint, loose debris, repair all cracks, clean and prepare surfaces to be painted following the manufacturer's instructions before applying paint or surface treatments. This preparation includes removal of oil, dust, and direct, loose rust, mildew, peeling paint or other contamination to ensure good adhesion. In all cases, the Contractor must remove all existing coats of primer and sealers if prior paint application is showing signs of improper adhesion, such as peeling, chipping, etc. All surfaces must be clea n and dry. The Contractor shall schedule cleaning and painting so dust and other contaminants will not fall on wet, newly painted surfaces. (c) The Contractor shall notify the Contracting Officer, Facility Manager or COR of problems anticipated for any minor preparatory work required, such as but not limited to, filling nail holes,

repairing cracks, repairing damage sections and cleaning surfaces to be painted, and priming any requisite areas. Clean all electrical covers and fixtures of paint debris or rep lace with new covers or fixtures after painting. Report all damaged or missing covers to the Contracting Officer, Facility Manager or COR prior to start painting. If electrical covers or light fixtures were previously reported damaged or missing, USG will provide.

(10) Materials Preparation: The Contractor shall mix and prepare paint following the manufacturer's

directions. (11) Application: The Contractor shall apply paint following the manufacturer's directions. Use

applicators and techniques best suited for substrate and type of material being applied. Do not paint over dirt, rust, scale, grease, moisture, scuffed surfaces, or conditions detrimental to formation of a durable paint film.

(a)Unless otherwise specified, the Contractor shall use a water-borne, matt finish silicone emulsion -based paint for mineral surfaces. (Containing no lead or mercury)

(b) On exterior surfaces, the Contractor shall apply a high quality exterior grade latex base paint that matches as closely as possible the existing color on the exterior of the property, or a color as otherwise specified by the COR. Prior to painting, the Contractor shall scrape, sand, f i l l, and prime the surface with a latex base primer. The Contractor should plan on e xtensive preparatory work prior to painting. The Contractor shall not apply exterior paint in rain, fog or mist, or when the relative humidity exceeds 85 percent; or to damp or wet surfaces. (c) The Contractor shall provide finish coats that are compatible with primers used. (d) The number of coats and film thickness required is the same regardless of application method. The Contractor shall not apply succeeding coats until previous coat has cured. The Contractor shall sand between applications where required to produce a smooth, even surface. (e) The Contractor shall apply additional coats when undercoats or other conditions show through final coat, until paint film is of uniform finish, color, and appearance. The Contractor shall have the Contracting Officer, Facility Manager or COR verify these conditions as required.

(12) Scheduling Painting: The Contractor shall apply the first coat to surfaces that have been cleaned,

pretreated or otherwise prepared for painting as soon as practicable, and bef ore subsequent surface deterioration. Allow sufficient time between successive coats to permit proper drying. Do not recoat until paint has dried.

(13) Minimum Coating Thickness: The Contractor shall apply materials at the manufacturer's

recommended spreading rate. The Contractor shall provide a total dry film thickness of the system as recommended by the manufacturer.

(14) Prime Coats: Before application of finish coats, the Contractor shall apply a prime coat as

recommended by the manufacturer to material required to be painted or finished, and which has not been prime coated.

(15) Brush Application: The Contractor shall brush-out and work brush coats into surfaces in an even film. The Contractor shall eliminate cloudiness, spotting, laps, brush marks, runs, sags or other surface imperfections. The Contractor shall draw neat glass lines and color breaks.

The Contractor shall apply primers and first coats by brush unless manufacturer's instructions permit use of mechanical applicators.

(16) Mechanical Applications: The Contractor shall use mechanical methods for paint application when permitted by manufacturer's recommendations, governing ordinances, and trade union regulations.

Wherever spray application is used, the Contractor shall apply each coat to provide the equivalent hiding of brush-applied coats. The Contractor shall not double-back with spray equipment building-up film thickness of two coats in one pass, unless recommended by the manufacturer.

(17) Upon completion of painting, the Contractor shall clean any glass and paint-spattered surfaces. The Contractor shall remove spattered paint by washing, scraping or other proper methods, and using care not to scratch or damage adjacent finished surfaces.

(18) The Contractor shall remove temporary protective wrappings after completion of painting operations.

Notes to Contractor for Painting Exterior Concrete: a. Concrete is a surface that presents a number of challenges to paint in terms of

adhesion and long-term durability, especially on horizontal concrete walking surfaces.

b. Test the concrete for porosity and moisture content. Smooth concrete with little or no porosity will not have sufficient texture for paint to gain strong adhesion.

c. Check porosity by sprinkling a little water on the surface. If it soaks in readily, paint will likely adhere to the surface after the necessary prep work is performed. Note: Some concrete, especially in garages, is pre-finished with a glossy coating to make the surface more resistant to moisture penetration and stains. This may greatly inhibit paint adhesion if it cannot be removed.

d. Concrete with excessive moisture will soon work to destroy the adhesion of any paint applied to it, so tape (duct tape works well) an 18-inch square piece of aluminum foil to the concrete surface and allow to remain for at least 24 hours. Remove the foil and look for condensation moisture on the side facing the concrete. If the foil is more or less dry, proceed with surface preparation and painting. If there is excessive moisture, the concrete surface is not a good candidate for painting.

e. Any bare or previously uncoated concrete should be etched. Etching imparts some roughness and porosity to bare concrete by using a muriatic acid solution or

similar product. When etching, it is extremely important to follow all label instructions regarding product usage.

f. After etching the surface, it is very important to clean the surface of any etching residue, such as released sand or lime. Rinse the surface until rubbing the fingers over the dried surface yields no chalky powder.

g. Apply a coat of latex or oil-based paint formulated especially for walking surfaces. Be sure to comply with all label directions regarding surface preparation and application.

h. Note on Alkalinity: One of the ingredients in concrete is lime, which is very alkaline in nature. Alkalinity can destroy paint adhesion, so it is recommended that all newly poured concrete be cured or be exposed for a minimum of 90 days before painting.

19. Texture Only - Walls

Occasionally, the Government may require a wall to be textured that has not previously been textured. The Contractor shall prepare the wall by filling and sanding any small holes or cracks with a suitable "non-shrinking" material. After preparatory work, the Contractor shall furnish and apply a texture type material. If any other walls within that area are textured, the texture material shall closely match the texture of any other existing textured walls in that area. The Contractor shall not be required to do less than one room on any individual task order.

20. Paint Exterior Trim

The Contractor shall apply the USG provide high quality exterior water-borne, matt finish silicone emulsion-based paint for mineral surfaces that matches as closely as possible the existing color on the exterior trim of the property, or a color as specified by the Contracting Officer. The Contractor shall scrap, sand, fill, and prime the trim with a latex base primer, prior to painting. The Contractor shall plan on extensive preparatory work prior to painting. The specifications for exterior paint apply, unless otherwise specified in the task order.

22. Remove Wall Covering

Upon assignment by task order, the Contractor shall remove the designated wall covering (Signs/wall markings, cork, mirrors, tiles, etc.). After removing the wall covering, the Contractor shall clean and make ready for painting the area. The Contractor shall remove and properly dispose of the old wall covering.

23. Plaster

The Contractor shall repair any damaged exterior plaster as directed by the COR. The plaster material shall be of a similar material that matches as closely as possible the existing plaster in texture and color.

24. Stucco

The Contractor shall repair any damaged stucco and remove any loose stucco before applying paint.

A-8 ROOFING WORKS GENERAL DESCRIPTION

A-8-1 Scope

The Contractor shall be required to remove the existing aluminum roofing sheet covering at the Vi sa

Pavilion area. The Contractor shall furnish and replace the roofing sheets with all accessories, the

additional concrete floor area as described in Section A-5 in this statement of works shall be covered

also. The removed aluminum roofing sheets shall be stored in an area identified by the COR. Attached

to statement of work is the drawing showing the area to be covered with the roofing sheets.

A-8-2 Description

Contractor shall be required to verify all measurements during inspection as the US Consulate

will not be held liable for any inaccurate quote.

The Contractor shall remove the existing aluminum roofing sheets at the pavilion, approximate

area of roofing sheets to be dismantled is 446m2.

Contractor shall be required to furnish and install new roofing sheets of 0.70mm gauge which

will be laid on the roof trusses. The approximate area for the roof covering which will take

account the extended concrete floor area at the North-west and North-East axis of the Visa

Pavilion area is approximately 558m2.

The Contractor shall be required to furnish and additional CHS (Circular Hollow Sections) pipes

to support the roofing sheets at the North west and North East axis where the floor slab has

been extended, the diameter of the CHS shall conform with the existing roof posts at the

Pavilion (Diameter of pipes is 100mm and thickness of pipe is 3mm). The pipes shall be welded

to steel plates of dimension 300mm x 300mm x 3mm thick. All specifications shall conform with

ASTM A1085.

The steel CHS pipes welded on the steel plates shall be anchored to the floor slab using hold

down bolts anchored into about 100mm deep of the concrete floor.

The rafters to be installed on the CHS pipes at the extended area (North-west and North east

axis) shall have a diameter of 100mm with thickness of 3mm. Spacing of rafters shall be

approximately 300mm apart.

The roof purlins shall be CHS pipes of diameter 50mm and 3mm thick, the spacing of the purlins

should not be spaced no further than 1.2m apart when using roofing sheets with thickness of

0.70mm.

The furnished roof truss elements shall be coated with marine based paints to reduce corrosion

due to effect of the seaside.

Provide roof gutter at both ends of the entire roofing area with down sprouts. The roof gutter

shall have supports using CHS pipes, linear meter of roof gutter sheets shall be approximately

80m which will be shared on both sides of the elevation where the additional floor area has

been introduced.

The Contractor shall furnish all required nails, screws, flashing, j -hooks, washer/gasket, sealant and all necessary hardware when installing the Aluminum roofing panels to provide a quality job per industry specification.

A-8-3 Design properties for circular hollow steel sections (CHS) according to EN1993-1-1

Definition of the cross-section

For typical Circular Hollow Sections (CHS) the geometric properties of the cross-section are defined in the following standards:

o EN 10210-2: Hot finished structural hollow sections of non-alloy and fine grain steels o EN 10219-2: Cold formed welded structural hollow sections of non-alloy and fine grain steels

The geometric properties that fully define the cross-section are external diameter D and wall thickness t. The notation is defined in EN1993-1-1 §1.7

Cross-section class

The classification of cross-sections is specified in EN1993-1-1 §5.5. The role of the classification is to identify the extent to which the resistance and rotation capacity of the cross-section are limited by local buckling of its parts.

Four section classes are identified:

o Class 1: Plastic bending moment resistance develops, and plastic hinge develops with rotation capacity adequate for plastic analysis.

o Class 2: Plastic bending moment resistance develops but the rotation capacity is limited by local buckling.

o Class 3: Elastic bending moment resistance develops but local buckling prevents the development of plastic resistance.

o Class 4: Elastic bending moment resistance cannot develop because local buckling occurs before the yield stress is reached at the extreme fiber. Effective widths are used to account for the effects of local buckling of compression parts.

The classification of the circular hollow sections (tubular sections) is specified in EN1993-1-1 Table 5.2. The class of the cross-section in bending and/or compression depends on the ratio of its diameter D to the wall thickness t, adjusted by the factor ε that takes into account the value of the steel yield stress fy:

ε = (235 MPa / fy)0.5

The diameter to wall thickness limits D / t for cross-section classification according to EN1993-1-1 Table 5.2 are presented below:

Classification of tubular sections according to EN1993-1-1 Table 5.2

Ratio D / t Section Class

D / t ≤ 50ε2 Class 1

D / t ≤ 70ε2 Class 2

D / t ≤ 90ε2 Class 3

D / t > 90ε2 See EN1993-1-6

For the case of circular hollow sections (tubular sections) that cannot be classified as Class 3 their strength and stability verifications should be based on EN 1993-1-6: Strength and Stability of Shell Structures.