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SPECIFICATION PREFACE SHEET

DEPARTMENT: Engineering / Civil Sheet 1 OF 27

AREA: Grundartangi Reduction Plant Spec. no. 00/02/TS002 Rev. C2

STANDARD

TECHNICAL SPECIFICATIONFOR

CONCRETE WORK

This Standard Technical Specification is subject to change without prior notice. The most recentissue will at all times be located on the Norurl web site, www.nordural.is

REV BY DATE CHKD APPRD REVISIONSP0 SbG 1999-09-15 DraftC1 NI 1999-09-29 TMS First issueC2 HJ 2004-05-07 J J Issued for Construction

NORURL - ENGINEERING

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NORURL STANDARD TECHNICAL SPECIFICATIONNORDIC ALUMINUM CONCRETE WORK

NA-00-02-TS002 Rev. C2

TABLE OF CONTENTS

1 INTRODUCTION ................................................................................................12 REFERENCES ...................................................................................................1

2.1 Principal standards.......................................................................................12.2 International codes and standards................................................................12.3 Other regulating requirements......................................................................3

3 CONTRACTOR'S DESIGN WORK AND SUBMITTALS.....................................33.1 Tests of concrete mixes................................................................................33.2 Submittals.....................................................................................................3

4 FOUNDATION FOR CONCRETE.......................................................................54.1 General.........................................................................................................54.2 Preparation of foundation.............................................................................6

5 FORMWORK AND ACCESSORIES ...................................................................65.1 General.........................................................................................................65.2 Falsework and formwork..............................................................................65.3 Geometrical tolerances.................................................................................65.4 J oints............................................................................................................75.5 Waterstops ...................................................................................................85.6 Bond breaker................................................................................................85.7 Expansion joint filler......................................................................................85.8 J oint sealant.................................................................................................85.9 Relief drains .................................................................................................9

6 CONCRETE SURFACES ...................................................................................96.1 Concrete surfaces in general........................................................................96.2 Formed surfaces ........................................................................................106.3 Unformed surfaces.....................................................................................106.4 Tolerances of surface irregularities.............................................................116.5 Special floor treatment................................................................................116.5.1 Floor hardeners...............................................................................................11

6.5.2 Nonslip aggregates .........................................................................................117 REINFORCEMENT AND EMBEDDED ITEMS.................................................12

7.1 General.......................................................................................................12 7.2 Reinforcing steel.........................................................................................127.3 Placing of reinforcement.............................................................................127.4 Reinforcement for prestressed concrete.....................................................127.5 Embedded items and concrete embedment............................................... 137.6

Non-shrinking concrete grouting.................................................................14

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STANDARD TECHNICAL SPECIFICATION NORURLCONCRETE WORK NORDIC ALUMINUMNA-00-02-TS002 Rev. C2

8 CONSTITUENT MATERIALS FOR CONCRETE ............................................. 148.1 General ......................................................................................................148.2 Cement ......................................................................................................148.3 Aggregates................................................................................................. 158.4 Mixing water, admixtures and additions ..................................................... 15

9 CONCRETE, REQUIREMENTS AND PROPERTIES ...................................... 169.1 General ......................................................................................................169.2 Concrete types........................................................................................... 169.3 Additional requirements for frost resistant concrete................................... 179.4 Chloride content......................................................................................... 179.5 Alkali reactivity ........................................................................................... 179.6 Consistence ............................................................................................... 18

10 BATCHING AND MIXING................................................................................. 1810.1 General ......................................................................................................1810.2 Plant and procedure................................................................................... 18

11 TESTING AND INSPECTION...........................................................................1811.1 General ......................................................................................................1811.2 Inspection classes...................................................................................... 1911.3 Inspection of concrete works...................................................................... 1911.4 Conformity control for concrete.................................................................. 1911.5 Production control of concrete.................................................................... 2011.6 Initial testing for concrete ........................................................................... 20

12 CONCRETING ................................................................................................. 2112.1 General ......................................................................................................2112.2 Concreting in cold weather......................................................................... 2112.3 Curing and protection in cold weather........................................................ 2212.4 Heat development control.......................................................................... 2212.5 Removal of formwork................................................................................. 22

13 REPAIR OF DAMAGE...................................................................................... 2313.1 General ......................................................................................................2313.2 Repair of leakage and cracks..................................................................... 23

14 PREFABRICATED CONCRETE ELEMENTS .................................................. 2314.1 General ......................................................................................................2314.2 Production.................................................................................................. 2314.3 Storage of products.................................................................................... 2314.4 Transport....................................................................................................2414.5 Testing, inspection and submittals............................................................. 2414.6 Installation.................................................................................................. 24

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NA-00-02-TS002 Rev. C2

STANDARD TECHNICAL SPECIFICATIONCONCRETE WORK

1 INTRODUCTION

These specifications set out the minimum requirements and the standards forconcrete work in Norurl construction contracts.

In this Document the following words and expressions shall have the meaninghereby assigned to them except where the context otherwise requires:

Engineer: The Owner or any person or organization employed or engaged atany time by the Owner and authorized by the Owner, in writing, from time totime to act on behalf of the Owner in the execution of the items covered by thisDocument, in whole or in any part, for any or all purposes provided in thisTechnical Specification.

Owner: Norurl hf (Nordic Aluminum Corporation Ltd.), an independent legalentity owned by Century Aluminum.

2 REFERENCES

2.1 Principal standards

(1) The standards

ST EN 206-1:2000 Concrete - Part 1: Specification, performance, productionand conformity, and

ENV 13670-1:2000 Execution of concrete structures - Part 1: Common

shall be met in all respects if not otherwise directed.

2.2 International codes and standards

(1) The following documents give support to or are referred to in this specification.

(2) European standards and publications:

EN 196 Methods of testing cement

EN 197-1 Cement - Part 1: Composition, specifications and con-formity criteria for common cements

ST EN 206-1 Concrete - Part 1: Specification, performance, productionand conformity

ST EN 933-2 Tests for geometrical properties of aggregates Part 2:

Determination of particle size distribution Test sieves,nominal size of apertures

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STANDARD TECHNICAL SPECIFICATION NORURLCONCRETE WORK NORDIC ALUMINUMNA-00-02-TS002 Rev.C2

EN 934-2 Admixtures for concrete, mortar and grout Part 2:Concrete admixtures - Definitions and requirements

EN 1652 Copper and copper alloys Plate, sheet, strip and circlesfor general purposes

ENV 1991 Eurocode 1: Basis of design and actions on structures

ENV 1992 Eurocode 2: Design of concrete structures

ENV 1994 Eurocode 4: Design of composite steel and concrete struc-tures

ST EN 12350 Testing of fresh concrete

ST EN 12390 Testing of hardened concrete

ST EN 12620 Aggregates for concrete

ST EN 13369 Common rules for precast concrete products.

ENV 13670-1 Execution of concrete structures - Part 1: Common

ST EN 28601 Data elements and interchange formats Informationinterchange Representation of dates and times

(3) International standards:

ISO 31-0 Quantities and units Part 0: General principles

ISO 565 Test sieves - Metal wire cloth, perforated metal plate andelectroformed sheet - Nominal sizes of openings

ISO 1000 SI units and recommendations for the use of their multi-ples and of certain other units

ISO 3310-1 Tests sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth

ISO 3310-2 Tests sieves Technical requirements and testing Part 2: Test sieves of perforated metal plate

ISO 6784 Concrete Determination of static modulus of elasticity incompression.

ISO 8601 Data elements and interchange formats Informationinterchange Representation of dates and times

(4) Norwegian standard:

NS 3576-3 Steels for reinforcement of concrete - Dimensions andproperties - Part 3: Ribbed bars B500C

(5) German standards:

DIN 1045 Structural use of concrete Design and construction- 6.2 Aggregate

DIN 4099 Welding of reinforcing steel; execution of welding work

and testing

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NA-00-02-TS002 Rev. C2

DIN 18541 Thermoplastics sealing strips for sealing joints in in-situconcrete

DIN 21521 Rock bolts for mining and tunnelling

(6) US standards:

ASTM C40 Organic impurities in fine aggregates for concrete

ASTM C227 Test method for potential alkali reactivity of cement-aggre-gate combinations (mortar-bar method)

ASTM C457 Practice for microscopical determination of air-void contentand parameters of the air-void system in hardenedconcrete

ASTM C666 Resistance of concrete to rapid freezing & thawing (proce-

dure A)ASTM C1260 Test method for potential alkali reactivity of aggregates

(mortar-bar method)

(7) BSI standards:

BS 3837-1 Expanded polystyrene boards - Boards and blocks manu-factured from expandable beads Requirements and testmethods

BS 5896 High tensile steel wire and strand, prestressing concrete

BS 4254 Two-part polysulphide-based sealants

2.3 Other regulating requirements

IBC Byggingarregluger nr. 441/1998 me breytingum nr.563/2000, 996/2001, 133/2002 & 425/2002 [IcelandicBuilding Code with amendments]

941/2002 Regluger um hollustuhtti [Regulation on health require-ments]

3 CONTRACTOR'S DESIGN WORK AND SUBMITTALS

3.1 Tests of concrete mixes

(1) Not later than 35 days prior to any concrete pours in permanent structures theContractor shall submit to the Engineer conclusive results of tests of the concretemixes to be used, carried out in accordance with 11, Testing and inspection, inparticular 11.6, Initial testing for concrete.

3.2 Submittals

(1) The Contractor shall submit the following data and documents to the Engineer for

inspection and approval in ample time before the relevant item is needed for the

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Work. The ample time period shall be directed by the Engineer after consultationwith the Contractor.

a) The design of falsework and formwork. The design shall include i.e.:

i. the layout of the falsework and formwork,

ii. supports and cladding material,

iii. form ties, type and pattern,

iv. type of form oil.

b) A certified mill report for each delivery lot of reinforcement.

c) Lift drawings and all detail drawings necessary to ensure the proper con-struction of each part of the Works.

d) Detailed reinforcement drawings and bar lists prepared on the basis of theDrawings, which will indicate only the main structural reinforcement re-quired in the structures. These reinforcement drawings and bar lists shallbe submitted to the Engineer for approval 28 days prior to cutting of rein-forcement.

e) Information on facilities for batching, mixing, transporting and testing con-crete, i.a. the following:

i. cement storage facilities and transport methods,

ii. the storage area and processing facilities for reinforcing steel,

iii. the main equipment and facilities for the batching and mixing of con-crete,

iv. production capacity of the batching and mixing plant in continuousoperation, m/h,

v. equipment and facilities for excavating, storing and processingaggregates, for controlling moisture content and for pre-heating incool weather,

vi. equipment and facilities for transport and placing of concrete,

vii. laboratory facilities.

(f) Information on facilities for curing concrete, such as:i. devices for heat treatment of concrete during the hardening process,

e.g. arrangements for internal cooling, and devices for monitoringheat development,

ii. facilities for curing concrete in cold weather,

iii. measures for preventing excessive drying of concrete surfaces.

(2) In ample time prior to start of concreting operations the Contractor shall applyfor the Engineer's inspection and approval of installed reinforcement and em-bedded items.

(3) The Contractor shall apply in writing to the Engineer for issue of a "Concretepour clearance" not less than 24 h prior to placing of a concrete lift. All

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formwork, reinforcement, embedded items and preparations for concreting ofthe lift must be completed before the clearance is issued. The Concrete pourclearance, prepared in triplicate, shall i.e. give account of:

a) date and hour of scheduled commencement and finish of placing,

b) location of placement,

c) concrete type,

d) estimated volume of concrete to be placed,

e) reinforcement placed,

f) expected temperature of air and concrete,

g) proposed methods for heating of forms, reinforcement, hardened concreteetc. in cold weather,

h) placement and compacting equipment,

i) curing methods including i.a. heat control of concrete, e.g. embeddedcooling system and insulation of forms and surfaces, concrete temperaturemeasurements, maturity control, expected strength development ofconcrete, removal of forms and prevention of premature drying of concretesurfaces.

(4) The Contractor shall not later than 14 days prior to concreting operations submitto the Engineer various information concerning his concrete activities, i.a. thefollowing:

a) names and qualification of the foremen for batching, mixing and placing ofconcrete,

b) proposed method for ascertaining that the concrete has obtained sufficientstrength for removal of forms and has become frost resistant,

c) proposed material for repair of concrete and method of application.

(5) The Contractor shall submit his "Production control manual" (cf. 11.1, General)to the Engineer for approval prior to implementation.

(6) The Contractor shall without undue delay submit to the Engineer any requestedinformation concerning his inspection and control of the concrete work.

(7) The Contractor shall submit his structural calculations and production drawingsfor prestressed concrete elements to the Engineer for approval.

4 FOUNDATION FOR CONCRETE

4.1 General

(1) The Contractor shall appropriately prepare any foundation for concrete prior toinstallation of formwork and the placing of concrete. Such preparation includesi.a.:

a) drainage of water from the surface,

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b) cleaning of rock surfaces with air-water jet or by other approved means,

c) placing of a layer of lean concrete or other approved cover on surfacessubject to weathering.

4.2 Preparation of foundation

(1) All fills and natural base materials on which concrete shall be placed must beadequately compacted with vibratory equipment suited to the conditions asdirected by the Engineer.

(2) Treatment of rock or gravel foundation prior to placing of reinforcement isdescribed in 7.3, Placing of reinforcement.

(3) Preheating of concrete foundation in cold weather is described in 12.2, Con-creting in cold weather.

5 FORMWORK AND ACCESSORIES

5.1 General

(1) Material and workmanship shall comply with ENV 13670-1:2000, 5 Falseworkand formwork.

5.2 Falsework and formwork

(1) Forms for outside concrete corners shall be chamfered 30 30 mm, exceptotherwise shown on the Drawings or directed.

(2) Form ties shall generally be of the cone and rod type or other approved type forwaterproof concrete members. The embedded metal rods shall terminate notless than 50 mm inside the formed face of the concrete, unless otherwiseapproved. A hole left in a face by a fastener shall be filled by an approvedmethod, cf. 13, Repair of damage.

(3) Form ties in sheath pipes may, if approved, be used through walls that are notsubject to unilateral water pressure. The sheath pipes shall subsequently be cutat least 50 mm inside the concrete surface and the hole filled with concrete,unless otherwise approved.

(4) Form ties shall be placed in approved patterns appropriate for the particularstructure.

(5) Limited amount of formoil shall be used, especially on the lower part of walls.

5.3 Geometrical tolerances

(1) The falsework and formwork shall be constructed so that deviations of thecompleted structure do not exceed the tolerances specified in standard ENV13670-1:2000, 10 Geometrical tolerances, and annex F, Guidance on geomet-rical tolerances, unless otherwise directed. The following requirements super-sede the general tolerances given by the standard:

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Surfaces not Surfaces exposedexposed to view to view

mm mm

Elevations 25 10Horizontal location 50 10Deviation from a 2 m longstraight-edge or appropriate ruler 20 6

(2) Geometrical tolerances indicated on the Drawings or directed by the Engineersupersede the preceding requirements.

(3) Accepted deviations from true line and grade shall not be cumulative. Forms forsubsequent concrete placement shall be aligned back to true line and grade assoon as possible with due consideration to the requirements of surface irregu-larities.

(4) Requirements of surface irregularities are specified in 6.4, Tolerances of sur-face irregularities.

(5) Tolerances for placement of embedded items are specified in 7.5, Embeddeditems and concrete embedment.

5.4 Joints

(1) J oints in concrete are either movement (deflection, expansion or contraction)joints or construction joints.

(2) Movement joints shall be constructed as shown on the Drawings. The Contrac-tor shall i.a. provide the various joint components and install these in accord-ance with the Drawings and the manufacturer's recommendations, or asdirected or approved.

(3) No reinforcement or fixed metal embedded in the concrete shall be continuousthrough a movement joint, except where expressly shown on the Drawings ordirected.

(4) Construction joints are the common boundaries of concrete lifts, or boundariesof prefabricated elements and in-situ concrete, not separated by a movementjoint. Generally construction joints will not be shown on the Drawings.

(5) Location of construction joints not shown on the Drawings or directed shall beproposed by the Contractor on lift drawings submitted to the Engineer forapproval.

(6) The face of a construction joint where watertightness is required must be appro-priately prepared mechanically or by 30 - 40 MPa water jet prior to the placingof the subsequent lift of fresh concrete. The preceding concrete lift shall besaturated by water but surface dry when the successive lift is placed.

(7) At horizontal construction joints on exposed surfaces, forms shall be construc-ted with strips to produce a straight joint at the exposed surface, unlessotherwise directed.

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5.5 Waterstops

(1) Waterstops shall be installed as shown on the Drawings or as directed.

(2) Detailed information on all waterstops, their properties, installation and standardsupport, shall be submitted to the Engineer for approval. No waterstop not ap-proved shall be used in the Work.

(3) Manufacturer's instructions shall be followed closely. Preformed junctions shallbe used where appropriate. All joints of sealing strips shall be welded by theappropriate device to the tensile strength at least 80 % of the parent material.

(4) Waterstops must be properly installed prior to placing of concrete so as to forma continuous watertight diaphragm in each joint. Dislocation by the concretingoperation must be prevented in an approved manner.

(5) For general civil work three types of waterstops are foreseen: Type A thermo-plastics sunken sealing strips for construction joints, type D thermoplasticssunken sealing strips for movement joints, and type C - injection tubes, wherestrips are not appropriate.

(6) Waterstops type A and D shall conform to DIN 18541. Waterstop type C shallbe the perforated injection tubes system with injected water cut-off grout(WEBAC Injektschlauch-System with the appropriate injection resin such asWEBAC 1403, or equal).

5.6 Bond breaker

(1) Bond breaker shall be applied where indicated on the Drawings and be of thetype shown or as directed.

(2) The material used for bond breaker must be approved by the Engineer for eachcase.

5.7 Expansion joint filler

(1) A filler shall be provided in expansion joints as shown on the Drawings or asdirected.

(2) If not otherwise specified, the expansion joint filler may be plate strips of ex-

panded polystyrene (24 kg/m), rockwool boards (150 kg/m), bitumen impreg-nated fibre boards, bitumen coated cork boards or other filler approved.

(3) Any material used for expansion joint filler must be approved by the Engineer.

(4) J oint backing rods shall be compatible with the joint sealant and shall be thetype recommended by the sealant manufacturer.

5.8 Joint sealant

(1) Field moulded joint sealants shall be either hot or cold applied materials which,upon curing, form an impermeable barrier to water, debris and any specified

chemicals. The cured materials shall be elastic, cohesive and remain adheredto the joint faces throughout the range of joint movement or service temper-atures. The sealants shall not be adversely affected by aging or weathering.

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(2) Sealants in horizontal joints, subject to pedestrian and vehicular traffic such asroadways and passageways, shall be one of the following:

a) Hot applied, self-levelling polyvinylchloride-coal tar compound with anallowable extension and compression of 25 %. No primer is required withthis material.

b) A two-component neoprene or polyurethane or a modified urethane coaltar compound, both cold applied and self-levelling, with an allowableextension and compression of 12,5 %. The manufacturers recommendedprimers shall be used with these sealants.

c) Silicone rubber sealant of adequate quality. Backer rods with silicone treat-ment shall be used.

(3) Sealants in vertical joints in walls or horizontal joints not subject to traffic shall

be either polysulfide or polyurethane compounds, cold applied at a nonsagconsistency.

(4) Preformed joint sealer shall have straight and parallel sides, shall be of virgincrystallisation-resistant noeprene, and shall be compatible with the concreteand with the lubricant adhesive used for installation. The joint sealer shall beflexible and pliable and retain its elasticity at temperatures from 30 to +100 C.A lubricant-adhesive approved by the sealer manufacturer shall be used in theinstallation of the preformed sealer.

(5) At least 56 days before its intended use, the Contractor shall submit to the Engi-neer a sample of the proposed sealing compound together with the manufacturer's

technical data and the details of the recommended method of application.

5.9 Relief drains

(1) Relief drains for reducing water pressure under or behind concrete structuresshall be installed and embedded where shown on the Drawings or as directed.The construction of the relief drains and materials for them are specified on theDrawings.

(2) The relief drains must be properly installed prior to placing of concrete to form acontinuous drain system. Penetration of dirt or concrete fines into the drainsmust be prevented in an approved manner.

6 CONCRETE SURFACES

6.1 Concrete surfaces in general

(1) Surface finishes are indicated on the Drawings.

(2) Generally the surface shall be free from honeycombs, segregation, loss ofcement or fine material, damage due to stripping of forms, boltholes, abruptirregularities caused by movement of forms or their components, loose knotsand similar features and bulges or depressions in the general plane of the

surface.

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(3) Care shall be taken to keep uniform colour of concrete surfaces permanentlyexposed to view, both regarding different lifts and repairs, unless otherwisedirected.

(4) Tolerance requirements for concrete surfaces are specified in 6.4, Tolerancesof surface irregularities. Geometrical tolerances for structures are specified in5.3, Geometrical tolerances.

6.2 Formed surfaces

(1) The classes of finish for formed surfaces are designated F1, F2.

a) Finish F1 (rough finish), shall apply to any surface concealed from view,including surface upon or against which backfill or concrete is to be placed,and formed surfaces of joints or blockouts. Minor blemishes caused by

entrapped air or water will be accepted. The surface treatment after removalof forms includes i.a. the filling of form-tie holes, the correction of majorsurface depressions and bulges, and the repair of defective concrete andcuring as specified.

b) Finish F2 (smooth finish), will generally apply to any surface exposed toview. After removal of forms, the surface shall be improved by removing allfins and other projections, washing down, and the filling of the mostnoticeable blemishes. Form-tie holes shall be filled along with all voids asspecified. In general, not more than 50 air voids of 5 - 15 mm diameter perm will be accepted. Air voids exceeding 15 mm in diameter shall berepaired. When filling holes and repairing defective areas of permanentlyexposed surfaces, effort shall be made to match the colour of the concrete.The use of release agents which may permanently stain or discolour thefinished surface will not be permitted.

6.3 Unformed surfaces

(1) The classes of finish for unformed concrete surface are designated as U1, U2and U3.

a) Finish U1 (screeded finish) will apply to an unformed surface to be coveredby fill or concrete. Finishing shall consist of levelling and screeding to

produce a uniform surface. This finish is also the first stage of finishes U2and U3.

b) Finish U2 (floated finish) will apply to an unformed surface not permanentlycovered by fill or concrete. Finishing shall consist of levelling and screedingto produce an even surface. Floating shall be started as soon as thescreeded surface has stiffened sufficiently to produce a surface that is freefrom screed marks and is uniform in colour and texture. This finish is alsothe second stage of finish U3.

c) Finish U3 (steel trowel finish) will apply for particular exterior surfaces andfor interior floors in buildings, except where a bonded concrete finish or tile

floor is foreseen, in which case finish U1 shall apply. For U3 finish floatingshall be performed until a small amount of mortar without excess water is

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brought to the surface. Steel trowelling shall start when the floated surfacehas hardened sufficiently to prevent an excess of fine material from beingdrawn to the surface. The finished surface shall be free from blemishes,

ripples and trowel marks. If a non-slippery surface is required, brooming ofthe steel trowel finished surface may be directed.

(2) Interior surfaces shall be sloped for drainage where shown on the Drawings.Exterior surfaces exposed to weather shall generally be sloped for drainage,even if not shown on the Drawings. The slope shall be at least 2 % but not morethan 3 %, unless otherwise directed.

6.4 Tolerances of surface irregularities

(1) Concrete surface irregularities shall not exceed the following tolerances:

Specified finish Permissible irregularitiesAbrupt Gradual

F1, U1 10 mm 20 mmF2, U2 5 mm 10 mmU3 1 mm 3 mm

(2) Abrupt irregularities are offsets caused by displaced or misplaced form sheath-ing or lining or form sections, or by loose knots in forms or otherwise defectiveform lumber. Abrupt irregularities shall be checked by direct measurement.

(3) Gradual irregularities are all other irregularities and shall be checked by a 2 m

long template. The template will be a straight edge for plane surfaces and a"shaped template for curved or warped surfaces.

(4) Tolerance of geometrical alignment are specified in 5.3, Geometrical tolerances.

6.5 Special floor treatment

6.5.1 Floor hardeners(1) Floor hardeners shall be as specified on the Drawings or directed.

(2) Liquid floor hardeners shall be a colourless chemical solution of magnesium or

zinc fluosilicate in combination with a wetting agent. Liquid floor hardeners arerecommended only for limiting the dusting of existing low quality floors. Shouldnot be used on exterior slabs exposed to freezing conditions.

(3) Floor hardeners, to minimize the dusting and increase the abrasion resistanceof new floors, shall be premixed dry shake hardeners consisting of size-gradedhard quartz aggregate and cementitious binder. A hardener with metallicaggregate may be specified for impact resistance or in areas of severeabrasion.

6.5.2 Nonslip aggregates

(1) Nonslip aggregates shall be a hard, well graded aluminium oxide. Size shall benoted in specification (extra coarse coarse medium).

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7 REINFORCEMENT AND EMBEDDED ITEMS

7.1 General

(1) Material and workmanship shall comply with ENV 13670-1:2000, 6 Reinforce-ment, and 7 Prestressing.

(2) For safety reasons, concrete in potroom areas shall contain no electricallyconductive supports, such as metallic chairs, bolsters, spacers or tie wires. Onlyspecial nonmetallic, nonconductive reinforcing supports shall be used.

7.2 Reinforcing steel

(1) The Contractor shall furnish and install all reinforcing steel for the concretenecessary for the completion of the Work.

(2) Reinforcing steel shall unless otherwise specified on the Drawings be thedeformed bar type of steel grade NS 3576-3 B500C.

7.3 Placing of reinforcement

(1) Work shall comply with ENV 1992-1-1, 5.2 Steel for reinforced concrete, and6.3.3 Reinforcing steel.

(2) The Contractor shall carry out reinforcement work in accordance with the appro-priate provisions of ENV1992-1-1 if detailed information is not on the Drawings.

(3) Reinforcement shall not be spot-heated before bending or straightening unless

approved.(4) Prior to placing reinforcement on rock or gravel foundation, the foundation shall

be covered with at least 50 mm thick layer of concrete or other approved cover.

(5) Welding of steel reinforcement shall conform to DIN 4099 or other approvedstandard.

(6) Welding close up to prestressed steel is prohibited.

(7) Spacing of bars shall be as provided in ENV 1992-1-1, 5.2.1.1 Spacing of bars.

(8) Lap length shall be according to ENV 1992-1-1, 5.2.4.1 Lap splices for bars orwires.

(9) If appropriate, reinforcement bars may be bundled as provided in ENV 1992-1-1, 5.2.7 Bundled high bond bars.

(10) Minimum concrete cover on reinforcement bars will be specified on the Draw-ings.

7.4 Reinforcement for prestressed concrete

(1) Material shall comply with BS 5896.

(2) Work shall comply with ENV 1992-1-1, 5.3 Prestressing units, and 6.3.4 Pre-

stressing steel, and with ENV 13760-1:2000, 7 Prestressing.

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(3) The Drawings will show the geometric dimensions and location of prestressedmembers, the prescribed loads and allowed tolerances. All detailing required forproduction and installation is the responsibility of the Contractor, and shall be

submitted to the Engineer for approval.(4) All materials for prestressing as well as ready made tendons shall carry identi-

fication marks. These shall be maintained until installation has been carried outand approved.

7.5 Embedded items and concrete embedment

(1) Before placing concrete, care shall be taken that all embedded items are firmlyand securely fastened in place as shown on the Drawings or otherwise directed,and that they are thoroughly clean. This applies both to items furnished by theContractor and to items furnished by others.

(2) Unless otherwise directed, deviations of 10 mm from design dimensions will betolerated for embedded items, provided that steel pads in first stage concrete forlater fastening of items do not extend into the design space for the relevantitems.

(3) The furnishing and installation of steel items which the Contractor shall embedin concrete will be as follows:

b) Embedded steel items furnished by the Contractor.

c) Embedded steel items furnished by others; items to be installed and em-bedded by the Contractor but furnished by others will be delivered by theEngineer.

d) Steel items furnished and installed by other contractors but which the Con-tractor shall embed in concrete.

(4) Embedded items may be placed in first stage or second stage concrete. Ifsecond stage, the concrete type depends upon circumstances:

a) If space is tight a non-shrinking concrete for embedment with upper sievesize of aggregate 16 mm shall be applied.

b) Non-shrinking concrete for embedment shall conform to 9, Concrete, re-quirements and properties, but shall include approved non-shrinkingingredients to prevent shrinking.

c) For second stage mass concrete the concrete type will be specified on theDrawings.

(5) Embedded conduits and air ducts:

(a) The Contractor shall furnish all material needed for the embeddedconduits and air ducts. All material shall be subject to approval by theEngineer.

(b) Embedded conduits shall be made of polyethylene, polyvinylchloride orother approved material for the intended installation. The thickness of theconduit walls shall be appropriate.

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(c) Embedded surfaces of inserts and sleeves shall be unpainted.

(d) Conduits for electrical cables shall have long sweep field bends whereverpossible but shall in no case have smaller radius bends than are recom-mended by the manufacturer of the conduits. The interior of the conduitsshall be smooth and suitable for installation of the cables.

(e) Conduits for electrical cables cut in the field shall have the ends properlymachine tapered with tools designed for the purpose, or end in a smoothend bell, as directed. The Contractor shall keep the number of conduitjoints to a minimum. Each embedded conduit joint shall be made securelywatertight by welding the conduits together using an approved method.

(f) Embedded air ducts shall be made of galvanised steel plates as shown onthe Drawings or directed.

(6) Anchor bolts shall conform to DIN 21521. Material shall be specified dependingon load requirements.

7.6 Non-shrinking concrete grouting

(1) Non-shrinking concrete grout to be placed under bearing plates, machinerybases, rails and where otherwise directed, shall be as thick as practicableexcept where specific thicknesses are shown on the Drawings.

(2) Non-shrinking concrete grout shall consist of an approved commercial cementbased non-shrinking grout, or of coarse aggregate (if appropriate), sand,cement, water and an approved non-shrinking ingredient, mixed in proportionsapproved by the Engineer.

(3) Forms for the grouting shall be installed where necessary, and care shall betaken that the grout fills all intended spaces, leaving no voids.

(4) Non-shrinking concrete shall be properly cured in an approved manner.

8 CONSTITUENT MATERIALS FOR CONCRETE

8.1 General

(1) Material and workmanship shall comply with EN 206-1:2000, 5.1 Basic require-ments for constituent materials.

8.2 Cement

(1) Cement shall conform to EN 197-1.

(2) The Contractor is responsible for the concrete mix design and for the use ofproper quantity of an appropriate type of cement for the particular concrete type,considering the provisions of this specification.

(3) Taking into account the end use of the particular concrete type, due attentionshall be paid to the alkali reactivity of the cement (cf. 9.5,Alkali reactivity) and to

its heat generation during the hardening process (cf. 12.4, Heat developmentcontrol).

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(4) Any cement type used in the Work must be approved by the Engineer.

(5) All bulk cement used in the Work shall be transported in weather tight cementtransport trucks and stored in adequately designed cement storage silos.

(6) All sacked cement used in the Work shall be delivered to the site in factorysealed bags. Damaged or broken bags will be rejected. Sacked cement shall bestored, immediately upon receipt at the site, in a dry, weathertight and properlyventilated building. All sacks shall be clearly and permanently marked by date ofreceipt at the site. This marking shall remain clearly visible on sacks in storage.

(7) The Contractor shall organise his transports so that cement is stored for theshortest possible time at the site. No cement stored at the site for more thanthree months shall be used unless retests prove it to be satisfactory accordingto EN 196.

8.3 Aggregates

(1) Aggregates shall conform to ST EN 12620:2000.

(2) All aggregates shall consist of clean, hard, dense, durable and uncoated mate-rials.

(3) The aggregates must not contain harmful amounts of humus and organicconstituents. This shall be ascertained through the methods of ASTM C40.

(4) The aggregates shall be tested for alkali reactivity as specified in 11.6, Initialtesting for concrete.

(5) The water-soluble chloride ion content of the sand and coarse aggregate,combined in the proportions intended for a particular mix, shall not exceed thevalues given in ST EN 12620:2000, table G.1 - Guideline maximum water-soluble chloride ion content of aggregate for concrete.

(6) Fines and conglomerates injurious to the concrete must not contaminate theaggregates.

(7) The aggregates shall be adequately processed and stockpiled in differentmaximum particle sizes for convenient use in concrete mixes.

(8) The upper sieve size D of aggregates shall be such as to best establish the

required properties of the concrete. The grading of aggregates shall conform toST EN 12620:2000, 4.3 Grading, but grain size distribution curve shall lie withinarea marked with number 3 in DIN 1045, 6.2 Aggregate, figures 1 - 4.

(9) All aggregates for concrete shall be obtained from approved borrow areas. Fineand coarse aggregates shall be processed from natural sand and gravel orcrushed rock.

8.4 Mixing water, admixtures and additions

(1) Water used for the concrete shall be fresh and clean. Potable water will beacceptable.

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(2) Admixtures and additions to the concrete shall comply with EN 206-1:2000,5.1.5 Admixtures & 5.1.6 Additions. They shall be compatible with constituentmaterials of the concrete and be appropriate for the actual construction condi-

tions.(3) Any proposal of admixture or addition to the concrete submitted by the Contrac-

tor shall include detailed information on the product. Any product used must betested for suitability (cf. 11.6, Initial testing for concrete) and approved by theEngineer.

9 CONCRETE, REQUIREMENTS AND PROPERTIES

9.1 General

(1) Concrete types will be prescribed on the Drawings, but the Contractor isspecifier, producer and user of the concrete mixes (cf. EN 206-1:2000, 3.1.37,38 & 39).

(2) Except otherwise specified herein or directed, work shall comply with EN 206-1:2000, 5 Requirements for concrete and methods of verification.

(3) The Engineer must approve any concrete type used in the Work.

9.2 Concrete types

(1) On the Drawings the concrete type will be designated as Cbb/cc:XEi-D, where

Cbb/cc indicates the compressive strength class of concrete (cf. EN 206-1:2000, 4.3.1 Compressive strength classes, table 7 - Compressive strengthclasses for normal-weight and heavy-weight concrete), XEithe exposure class(cf. EN 206-1:2000, 4.1 Exposure classes related to environmental actions,table 1 - Exposure classes), and D the upper sieve size of the aggregate in mm(cf. ST EN 12620:2000, 4.2 Aggregates sizes, table 1 - Sieve sizes for speci-fying aggregate product sizes, Basic set).

(2) The table EN 206-1:2000, annex F, table F.1, Recommended limiting values forcomposition and properties of concrete, is informative (the requirements of 9.3,Additional requirements for frost resistant concrete, supersede the recom-mendations of table F.1). Note also EN 206-1:2000, 5.2.5 Use of additions.

(3) The general concrete types for the Project are listed as follows. Concrete typeswill be designated on the Drawings, where upper sieve size of aggregate will beincluded.

a) C12/15:X0-D: Concrete without reinforcement or embedded metal, notsubject to freeze/thaw, abrasion or chemical attack.

b) C16/20:X0-D: Concrete without reinforcement or embedded metal, notsubject to freeze/thaw, abrasion or chemical attack.

c) C20/25:XC1-D: Concrete designed for dry or permanently wet environment.

d) C30/37:XC1-D: Concrete designed for dry or permanently wet environment.

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e) C30/37:XF3-D: Concrete designed for concrete surfaces exposed to highwater saturation and freezing, but not subject to de-icing agent or seawater.

Special concrete types may be prescribed in the Drawings for particular pur-poses.

9.3 Additional requirements for frost resistant concrete

(1) The following requirements are made for frost resistant concrete, C30/37:XF3:

a) Water/cement ratio < 0,45

b) Minimum air content of fresh concreteat placement 5 - 7 %

Spacing factor (cf. ASTM C457)

of the entrained air void system: < 0,20 mmSpecific surface: > 25 mm-1

c) Maximum Cl- by mass of cement < 0,2 % (cf. EN 206-1:2000, 5.2.7)

d) Frost resistance tested byASTM C666, procedure A:

Durability factor > 80

e) Water penetration (cf. ST EN 12390-8)

maximum depth < 50 mm

estimated average depth < 20 mm

9.4 Chloride content

(1) The maximum chloride content of concrete shall be in accordance with EN 206-1:2000, 5.2.7 Chloride content, table 10 - Maximum chloride content of con-crete.

(2) Chloride content class for concrete containing steel reinforcement shall be Cl0,20 (maximum Cl- content by mass of cement 0,20 %) and for concrete con-taining prestressing steel reinforcement Cl 0,10 (maximum Cl- content by massof cement 0,10 %), unless otherwise directed by the Engineer.

9.5 Alkali reactivity

(1) The alkali reactivity of aggregates in combination with the proposed cementshall be tested. Tests shall be conducted using ASTM C227 or ASTM C1260,as directed by the Engineer. If tests are made according to ASTM C227, theexpansion of specimens shall generally be less than 0,1 % after 12 months; ifthe cement contains more than 5 % silicafume the expansion shall be less than0,06 %. If tested according to ASTM C1260, the expansion of specimens shallbe within 0,1 % after 14 days.

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9.6 Consistence

(1) Consistence of concrete mix shall be determined as specified in EN 206-1:2000, 5.4.1 Consistence.

(2) The consistence of the mix when placed shall be adequate for proper placing ofwell compacted concrete without honeycombs or segregation. Rather thanvarying the cement dosage beyond what is needed for strength, adequateworkability of concrete shall be achieved by the use of admixtures, includingsuperplasticisers, use of which shall follow stipulations of EN 206-1:2000, 5.2.6,Use of admixtures.

10 BATCHING AND MIXING

10.1 General(1) Material and workmanship shall comply with EN 206-1:2000, 9.6 Personnel,

equipment and installation, 9.7 Batching of constituent materials, and 9.8 Mixingof concrete.

10.2 Plant and procedure

(1) The batching and mixing plant shall:

a) have capacity of batching and mixing concrete at a rate in excess of theContractor's peak placing requirements. A standby mixer with a capacity ofnot less than 40 % of the peak placing requirements shall be available at

all times for use during critical concreting operations;b) be capable of combining the aggregates, cement, admixtures and water

into a uniform mixture within the proper time limit and of discharging thismixture without segregation. The plant shall have adequate facilities foraccurate measurement and control, and automatic recording of each ofthe constituting materials entering the mix and of the amount of concretedispatched from the plant.

(2) All aggregates shall have consistent moisture content and grading whendelivered to the batching plant.

(3) The Contractor is responsible for providing mixes that comply with this specifi-cation and the Drawings.

11 TESTING AND INSPECTION

11.1 General

(1) Work shall comply with EN 206-1:2000, 8 Conformity control and conformitycriteria, 9 Production control, 10 Evaluation of conformity, and annex C,Provisions for assessment, surveillance and certification of production control,and with ENV 13670-1:2000, 11 Inspection, and annex G, Guidance on

inspection.

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(2) The Contractor shall keep logs on all his concrete activities, i.e. production,placing, supervision and production control, inspection and testing. These logsshall at any time be available to the Engineer for examination.

(3) The Engineer may at any time inspect and test any Contractor's equipmentintended for batching, mixing, transporting, placing and testing concrete.

(4) The Engineer will occasionally take his own samples from the concrete mixesand the constituent materials of the concrete for testing. The Contractor shallassist the Engineer in obtaining such samples.

(5) The Contractor shall maintain a documented production control system andkeep a "Production control manual" in accordance with EN 206-1:2000, 9.2Production control system. The manual shall be submitted to the Engineer forapproval prior to implementation. The control tests and procedures required inrespect of EN 206-1:2000, 9.9 Production control procedures, tables 22, 23 and24, shall be listed in the Production control manual.

(6) The Engineer exercises the functions of the "inspection body" as well as the"certification body" defined in EN 206-1:2000, annex C - Provisions for assess-ment, surveillance and certification of production control.

11.2 Inspection classes

(1) The Engineer will classify structures or components of structures into inspectionclasses as required in ENV 13670-1:2000, 11.1 Inspection classes. Cf. ENV13670-1:2000, annex G Guidance on inspection, table G.1 - Guidance for the

selection of inspection class.(2) If the Engineer has not classified a structure component into an inspection

class, it shall be assumed to belong to inspection class 3.

11.3 Inspection of concrete works

(1) The Contractor shall supervise and inspect the concrete works so as to fulfill theprovisions of this specification and of ENV 13670-1:2000, 11 Inspection. Thisapplies to inspection of materials and products, of concreting execution, offalsework and formwork, of reinforcement and prestressing if applicable, ofconcreting operations and of precast concrete elements.

(2) Where inspection reveals non-conformity, appropriate measures correspondingto the Contractor's approved Product control manual shall be taken to ensurethat the structure remains fit for its intended purpose.

11.4 Conformity control for concrete

(1) The Contractor shall perform conformity control for concrete as specified in EN206-1:2000, 8.2 Conformity control for designed concrete.

(2) The concrete family concept, as specified in EN 206-1:2000, 3.1.14, concretefamily, and annex K, Concrete families, can be applied to strength classes up to

C40/50, if not otherwise directed by the Engineer.

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(3) In the event of non-conformity the Contractor shall take actions in accordancewith EN 206-1:2000, 8.4 Actions in the case of non-conformity of the product.

11.5 Production control of concrete(1) All concrete shall be subject to production control under the responsibility of the

Contractor as specified in EN 206-1:2000, 9 Production control.

(2) All relevant data from the production control shall be recorded, see EN 206-1:2000, 9.3 Recorded data and other documents, and submitted to the Engi-neer.

11.6 Initial testing for concrete

(1) Prior to the start of concrete activities at the site and in the case of using a new

concrete composition, initial testing shall be performed in accordance with EN206-1:2000, 9.5 Concrete composition and initial testing, and annex A, Initialtest.

(2) The initial testing shall be started at least 119 days prior to commencement ofany concreting of Permanent Work, unless another period is agreed betweenthe Contractor and the Engineer. All initial tests shall be completed when theContractor submits his design of concrete types to the Engineer for approval notlater than 28 days prior to any concreting of Permanent Work.

(3) Before the commencement of the initial tests the Contractor shall submit to theEngineer certificates on the compliance of the constituent materials of concrete

with the specifications. This applies i.a. to:(a) mill test report covering the physical and chemical properties of any

cement proposed for use in the Work,

(b) sieve analysis of aggregates and reports on the physical properties of theaggregates,

(c) test reports showing alkali reactivity of the proposed aggregates in combi-nation with the proposed cement,

(d) test reports showing frost resistance of the proposed aggregates in combi-nation with the proposed cement,

(e) certifications for chemical admixtures for concrete.

(4) A laboratory approved by the Engineer shall perform initial tests. The testresults shall i.a. comprise:

a) results of assessment of frost resistance, according to ASTM C666;

b) test results of alkali reactivity, cf. 9.5,Alkali reactivity;

c) the grain size distribution of the aggregates;

d) content of each of constituent materials of the concrete;

e) water-cement ratio (w/c);

f) entrained air;

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g) workability of the fresh concrete;

h) compressive and tensile strength;

i) density;j) water tightness.

(5) The criteria for adoption of initial tests of compressive strength shall be asstipulated in EN 206-1:2000 annex A, A.5 Criteria for adoption of initial tests.

(6) The specified properties for each type of concrete shall be fulfilled withoutexcessive use of cement.

12 CONCRETING

12.1 General(1) Work shall comply with this specification and ENV 13670-1:2000, 8 Concreting.

(2) Concrete shall be inspected at the point of placing.

(3) The scope for inspection of concreting operations is stipulated by ENV13670:2000, annex G, Guidance on inspection. Table G.3 - Inspection of freshconcrete, gives guidance on the minimum level of inspection.

(4) "Concrete pour clearance" (cf. 3.2, Submittals, subclause (3)) will not be issueduntil the Engineer has approved all preparation and pre-concreting operations.

(5) Curing shall be in accordance with ENV 13670-1:2000, 8.5 Curing and protec-tion, if not otherwise stated herein.

(6) The minimum curing period for concrete in surface structures shall be twice theperiod stipulated in ENV 13670-1:2000, annex E, table E.1, Minimum curingperiod for prEN 206:1997 exposure classes other than X0 and XC1. This isvalid also for exposure classes X0 and XC1, except otherwise directed.

12.2 Concreting in cold weather

(1) Concrete placement shall not commence without approved special provisions ifambient temperature below 3 C is expected. Such provisions include i.a.:

a) surfaces adjacent to the concrete lift to be placed shall be heated to atleast 3 C prior to pouring of concrete,

b) forms shall be adequately insulated to keep concrete temperature above3 C, taking into account the shape of the concrete member and theexpected heat generation in the concrete.

(2) The concrete may be heated during batching and mixing. The following criteriashall not be exceeded:

a) the maximum temperature of fresh concrete shall not exceed 25 C duringmixing, transporting and placing,

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b) mixing water shall not be heated above 60 C, unless it is mixed with theaggregates before cement is added; care must be taken that neither quickset nor flash set occurs,

c) the aggregates shall be heated uniformly and carefully; all frozen lumps,ice and snow shall be eliminated before entering the concrete mix;average aggregate temperature shall not exceed 60 C and maximum spottemperature shall be below 100 C.

12.3 Curing and protection in cold weather

(1) The surface temperature of concrete shall be kept above 3 C until the concreteis frost-resistant, i.e. has acquired compressive strength of fc > 10 MPa.

(2) The strength development of the concrete shall be deduced from that of compa-

rable representative specimens, or by cored cylinders.(3) Minimum curing period for concrete is specified in 12.1, General. For concrete

surface temperature below 5 C, the duration of curing shall be extended for thenumber of days the temperature has been below 5 C.

(4) Special curing may be specified for particular structures in the Drawings.

12.4 Heat development control

(1) To avoid surface cracking caused by heat generated in the concrete, thetemperature difference between a measuring point at the surface and ameasuring point in the centre of a concrete body, or 1000 mm inside the surface

if the body is more than 2 m thick, shall be less than 20 C, if not otherwiseapproved by the Engineer. The location of the measuring point at the surfaceplane shall be defined as 10 mm inside the surface on a perpendicular projec-tion of the structure member's centre point to the surface plane.

(2) Temperature difference across construction joints shall be less than 15 C atthe time of concrete placement.

(3) The maximum temperature of the concrete shall not exceed 55 C except ap-proved by the Engineer (cf. ENV 13670-1:2000, 8.5 Curing and protection, sub-clause (8)).

12.5 Removal of formwork

(1) Provided that requirements for concrete temperature and moisture are fulfilled,the conditions for the removal of formwork and falsework shall be:

a) vertical forms may be removed when the concrete has attained a com-pressive strength of 6 MPa, deduced from the strength development ofcomparable test specimens cured under similar conditions;

b) beam, deck and slab shoring shall not be removed until the concrete hasobtained 75 % of its design strength, deduced equally.

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13 REPAIR OF DAMAGE

13.1 General

(1) Imperfections in concrete shall be repaired as soon as practicable and asapproved. Fins and encrustations shall be neatly removed from exposedsurfaces. Irregularities exceeding the limits specified in 6.4, Tolerances ofsurface irregularities, shall be reduced by bush hammering and grinding.

(2) Approximately 25 mm deep cuts shall be made perpendicular to the surfacearound areas of defective or damaged concrete, the damaged concrete shall bechipped off to sound base, and replaced with filling. The filling for repair shall becommercial repairing materials or concrete, as approved, applied as recom-mended by the manufacturer. Concrete reparations shall be cured and protec-ted in the same way as concrete.

(3) Any damage observed in the concrete which may have structural conse-quences, leading to reduced safety of the construction or impaired use of thefacilities, shall be repaired so as to obtain the specified strength and function-ality. Such repairs may include demolishing and reconstructing the damagedstructure member.

13.2 Repair of leakage and cracks

(1) The Contractor shall repair all leakage spots in concrete joints or elsewhere byan approved method.

(2) In concrete members with unilateral water pressure, leaky cracks shall be madewatertight by injection of an approved grout, e.g. polyurethane water cut-offgrout. This applies to any crack that causes wet spots.

14 PREFABRICATED CONCRETE ELEMENTS

14.1 General

(1) The Contractor shall furnish, manufacture and install prefabricated concreteelements as shown on the Drawings and directed.

14.2 Production

(1) Production of the prefabricated concrete elements shall comply with the designdata given on the Drawings and in these specifications.

14.3 Storage of products

(1) The Contractor shall store the products safely both as regards the prefabricatedunits and all personnel.

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14.4 Transport

(1) Transport of prefabricated elements shall be carried out using adequate liftingand transporting equipment to ensure safe transport and delivery.

(2) The Contractor shall follow instructions given on the Drawings regardinglocation and details of hook-up points.

14.5 Testing, inspection and submittals

(1) The Contractor shall submit his structural calculations and production drawingsfor items designed by him to the Engineer for approval.

(2) The Contractor shall apply for an "Installation approval" 24 h in advance ofinstalling prefabricated elements, or in less time provided that preparatory workhas been completed. All temporary support work, formwork, reinforcement, em-

bedded items and other preparations must be completed before the approval isissued.

(3) The Contractor shall before applying for Installation approval and before startingtransport of prefabricated elements inspect at least the following items:

a) the elements tolerances are within specified limits,

b) hook-up points are according to the Drawings,

c) supporting structures for the elements are complete,

d) strength of concrete members carrying the elements is adequate,

e) access routes are open and safe,f) lifting devices and equipment is adequate,

g) the needed manpower is available.

14.6 Installation

(1) The Contractor shall install the prefabricated elements and secure their positionand stability until they are permanently secured in the final structure.

(2) The Contractor shall design and carry out all temporary support operations

needed for safe installation of prefabricated elements.(3) The Contractor shall furnish and place the concrete grout needed for installation

of the prefabricated elements.

(4) After erection of precast elements they shall fulfil the requirements of maximumdeviation from design dimensions as directed in 5.3, Geometrical tolerances, ifnot otherwise directed in relevant specifications.

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