civil works specification for fiji national ... – proposed three storey building for fiji maritime...

CIVIL WORKS SPECIFICATION

For

FIJI NATIONAL UNIVERSITY

PROPOSED THREE STOREY BUILDING

FOR FIJI MARITIME ACADEMY, SUVA

March 2018

(Tender Issue)

FNU – Proposed Three Storey Building for Fiji Maritime Academy, Suva

Civil Works Specification

HLKJacob Limited

Table of Contents

1. Clearing, Earthworks, Site Works and Road Formation 4

1.1 GENERAL 4

1.2 CLEARING & GRUBBING 4

1.3 STRIPPING 4

1.4 TOPSOIL 5

1.5 EARTHWORKS 5

1.5.1 CLASSIFICATION OF MATERIALS 5

1.5.2 EXCAVATION 6

1.5.3 Foundation Preparation 7

1.5.4 Placing Fill Between Under Sub-Base 8

1.5.5 Fill Moisture Control 8

1.5.6 Fill Compaction 9

1.5.7 Compaction Criteria 9

2. PAVEMENT SUB-BASE 10

2.1 GENERAL 10

2.2 MATERIALS 10

2.2.1 Description 10

2.2.2 Definitions 10

2.2.3 Extraction 11

2.2.4 Source Rock 11

2.2.5 Product 11

2.2.6 Water 14

2.3 CONFORMITY WITH DRAWINGS 14

2.4 SPREADING 14

2.5 TEST ROLLING 15

2.6 PROTECTION OF COMPACTED LAYERS 15

3. STORMWATER DRAINS 16

3.1 SCOPE 16

3.2 PIPES 16

3.3 COMPONENTS - CESSPITS, MANHOLES 17

3.4 MATERIALS 17

3.4.1 Pipes & Precast Reinforced Open Concrete Box Culverts Including ACO

Drains 17

3.4.2 Concrete 17

3.4.3 Cement 17

3.4.4 Reinforcing Rods 17



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3.4.5 Mortar 18

3.5 CONSTRUCTION OF ALL CAST IN-SITU ITEMS 18

3.5.1 Placing concrete 18

3.5.2 Boxing 18

3.6 EXCAVATION AND BACKFILLING 18

3.6.1 Excavation 18

3.6.2 Backfilling 19

3.6.3 Subsoil Water 19

3.7 PIPE LAYING PROCEDURE 19

3.7.1 Bedding 19

3.7.2 Laying 19

3.7.3 Testing of Stormwater Pipes 20

3.8 Headwalls and Outfall Structures 20

3.8.1 EXCAVATION 20

3.8.2 LAYING 20

3.9 DRAINAGE TRENCHES AT BASE OF RETAINING WALLS 21

3.9.1 DRAINAGE TRENCH: 21

3.9.2 DRAINAGE PIPE 21

3.9.3 TRENCH BACKFILL 21

3.9.4 CONSTRUCTION 22

4. CONCRETE, FORMWORK AND REINFORCEMENT FOR PAVEMENT 23

4.1 SCOPE 23

4.2 MATERIALS 23

4.3 FORMWORK 26

4.4 SURFACE FINISH 27

4.5 REINFORCEMENT 29



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1. CLEARING, EARTHWORKS, SITE WORKS AND

ROAD FORMATION

1.1 GENERAL

The works under this section of the Specification comprises the clearing, stripping, earthworks and

construction of road formation to the specified subgrade levels.

This Specification shall be read in conjunction with AS 3798, "Guidelines on Earthworks for

Residential and Commercial Developments".

1.2 CLEARING & GRUBBING

Clearing includes the removal of all trees and other vegetation, rubbish, stumps, pipes, fences, stone

walls, surface boulders, or other material that is not required in the finished contract.

Certain trees may be designated for saving, and these shall be carefully preserved. The landscaper

land architects approval must be obtained prior to removal of any trees.

Clearing shall include all the area affected by excavation and filling together with sufficient additional

area on which to stockpile stripped topsoil, and may also include further areas as shown on the plans

within the area of the development or subdivision.

Cleared material may be burnt on site unless otherwise directed, and provided such burning is allowed

by the relevant Authorities and carried out in compliance with their requirements. The Contractor is

responsible for obtaining a fire permit, and for any costs relating to such. All ash and residual material

from burning shall be removed from the site. The Contractor is responsible for establishing a tipping

point for all other rubbish, and for any fees relating to such.

1.3 STRIPPING

The area on which the fill is to be placed and the area from which the cut is to be removed should be

stripped of all vegetation and of such soils as are deemed by the Consultant Engineer to be unsuitable

to support the proposed loadings or for incorporation in fills. Topsoil will need to be stripped to spoil

as unsuitable material or stockpiled in positions as required for subsequent re-vegetation. Any

material which the Consultant Engineer considered will inhibit or prevent the satisfactory placement

of subsequent fill layers will not be allowed to remain in the foundations of fills or will be treated as

directed as directed by the Consultant Engineer.

Stockpile locations will be subjected to the approval of the Consultant Engineer, and regardless of

this approval will be chosen so that they are unlikely to initiate instability of either the stockpile or

the natural ground. Stockpile sites will also be chosen so that the stockpile does not inhibit natural

drainage of the area.



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1.4 TOPSOIL

Topsoil shall be removed over the area which will be occupied by the complete works plus a

clearance of 2 metres. Topsoil shall be placed in a stockpile clear of the work to enable its re-use in

landscaping and re-vegetation.

Unsuitable material includes topsoil, peat and other highly organic soils, logs, stumps, perishable

material, rubbish, material susceptible to spontaneous combustion, free draining susceptible to

scouring, very fine sand, silt and organic clay and material with a CBR<1. Such material shall be

excavated and disposed off-site except for top soil required for vegetation. Dispersive soils can be

used only in accordance with guidelines provided by a Geotechnical Engineer. Where unsuitable

material exists in excessive depths the advice of a Geotechnical Engineer is required. The Contractor

shall lightly scarify the surface of the areas to receive topsoil to a depth of 50 mm. This shall be

achieved by use of a rigid fine harrow making at least 3 passes or an approved alternative method.

Topsoil shall be spread over the prepared surface in sufficient quantity to result in a compacted

thickness 100 mm or thicker to make use of all topsoil stripped from the site. The placed topsoil shall

be lightly harrowed to give a uniform appearance and compacted by flat rolling.

The Contractor shall restore any areas where significant gulleying or erosion occurs during the

maintenance period. The Contractor shall make all allowances for restoration, including re-spreading

topsoil, in his lump sum tender price.

1.5 EARTHWORKS

1.5.1 CLASSIFICATION OF MATERIALS

Excavated materials shall broadly be defined as:

a) Earth:

That material which can be excavated and removed directly by normal, modern well operated

mechanical excavating plant. Any soft rock capable of being broken out by Caterpillar D8

size tractor in good working order fitted with a single shank ripper and operating on a near

horizontal surface will come into this category.

b) Hard Rock:

That material which cannot be ripped by a Caterpillar D8 sized tractor in good working order

fitted with a single shank ripper and operating on a near horizontal surface requiring either a

larger machine or the use of explosives to break up before being handled by mechanical

equipment. When the Consultant Engineer is satisfied that blasting techniques are necessary

he shall require evidence from the Contractor that a qualified explosives expert is being

employed and that all appropriate statutory regulations are being observed. When hard rock is

believed by the Contractor to have been encountered he shall immediately notify the

Consultant Engineer who shall rule as to whether the material is hard rock and if so make an

assessment of the volume to be excavated.



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Incidental hard rock boulders occurring within the limits of the earth of greater than one

cubic metre shall rank as hard rock; and those of smaller dimensions as earth

c) Unsuitable or Saturated Materials

Where materials have to be excavated by special machinery (such as draglines) and

techniques due to its situation and nature. All cost relating to treatment and or disposal of all

unsuitable material including loading onto trucks for disposal off site or for spreading drying

sufficiently and re-use as bulk fill on site as directed by the Consultant Engineer shall be

included in the Contractor’s lump sum tender price.

No placing or backfilling shall commence until the Consultant Engineer has inspected and if

necessary levelled the excavation.

1.5.2 EXCAVATION

a) General

Excavation shall be by means of scrapers, bulldozers, hydraulic excavators, loaders, and

trucks or other self-propelled bulk earth-moving machinery.

The Contractor shall ensure that the excavated surface is free draining at all times and stockpile

material in a manner that it is free from water contamination. Should the material become

unsuitable, he shall treat or replace the material as directed by the Consultant Engineer at his

own expense.

In pricing bulk earthworks, the Contractor shall allow for all costs associated with the

excavation, uplifting, transporting, placing and compacting as specified and shown on the

Drawings

Excavation shall be completed to the limits and grades shown on the plans

b) Benching

Shall be carried out where fill is to be placed on sloping ground (generally steeper than 6

horizontal to 1 vertical) These benches shall be cut nearly horizontally with fall towards the

fill area and shall be free draining. The width and height of the bench will depend on the

original ground slope. The rear batter of the bench shall have a slope of about 1 horizontal to

2 vertical, unless otherwise approve by the Consultant Engineer.

c) Limits of Excavation

Care shall be taken that ground beyond the limits of the work shown on the plans is not

disturbed by excavation procedures. Any slips which occur as a result of negligence on the

part of the Contractor shall be made good at his cost and as directed by the Consultant

Engineer.

Excavation shall be carried out to the lines, levels, dimensions and slopes shown in the

Drawings. The excavated faces shall be neatly trimmed and the top edges of the cuttings neatly

rounded. Under cutting of slopes will not be permitted under any circumstances.



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Excavation shall be carried out in such a manner as to prevent erosion or slips, working faces

shall be limited to safe heights and slopes, and surfaces shall be drained to avoid ponding and

erosion.

Overhanging, loose or unstable material likely to slip should be cut back removed or stabilised.

Rock cuttings and exposed rock surfaces shall be excavated so as to obtain smooth, uniformly

trimmed surfaces. Batters in cuttings shall be carried around curves in an even and regular

manner. Finished batters shall not have a slope steeper than that specified.

d) Quantities

Quantities shown in drawings are indicative only and the Contractor must make his own check

on their accuracy and price his tender accordingly.

The volumes scheduled are solid volumes as determined from the longitudina1 sections, cross

sections, or standard details provided

The Contractor must allow for overbreak in determining his price for rock excavation - either

bulk, or in trenches.

1.5.3 FOUNDATION PREPARATION

The ground surface exposed after stripping and on which fill is to be placed shall be shaped to assist

drainage. The exposed surface shall then be moisture conditioned to within the range of 85% to 115%

of the optimum moisture content as determined in the standard compaction test and the upper layer

of not less than 150 mm shall be compacted to a minimum dry density ratio of 98% Standard Proctor

(AS 1289.E4.1). Any soft or unstable areas exposed during this compaction process are to be treated

by further moisture conditioning or by excavation and replacement with selected fill material. This

replacement fill is to be compacted to a minimum dry density ratio of 98% Standard Proctor. No fill

shall be placed on the prepared foundation prior to it being inspected and approved by the Consultant

Engineer. At the time of his inspection, the Consultant Engineer may request the contractor to test

roll the foundation area or perform compaction tests.

The Contractor must allow in his lump sum tender price for all works associated with foundation

preparation, inspection and test rolling. If the Contractor believes he has carried out sufficient

moisture conditioning and compaction work, and that the soft or unstable areas are due to weak

foundation soils, he shall notify the Consultant Engineer who will then assess the preparation works

carried out and advise on the required soft area treatment. The Contractor must allow in the lump sum

tender price for compaction tests as required by the Engineer.

Where fill is to be placed across generally soft or swampy ground, it may not be practical to achieve

compaction of the existing or stripped surface. Where the method of placement of fill across such

area has not been specified elsewhere or shown on the Drawings, and such conditions are encountered,

the Contractor shall notify the Consultant Engineer immediately.

Where fill is to be placed directly onto rock (including undisturbed soapstone), the exposed surface

shall be tined or scarified to a depth of 150 mm minimum and re-compacted with a pad foot roller.



HLKJacob Limited

The Consultant Engineer shall assess the condition and direct the contractor to either excavate and

treat the materials or excavate and replace the materials as appropriate, or use 'Soft Ground'

1.5.4 PLACING FILL BETWEEN UNDER SUB-BASE

Fill material shall be placed in near horizontal layers of uniform thickness deposited systematically

across the fill area. The thickness of each layer should be appropriate for the equipment used, but not

exceeding 200 mm 1oose thickness. At cut to fill junctions, and at the edges of fills, the foundation

shall be excavated or "boxed" so that the minimum thickness of fill to be placed is 100 mm.

The method of excavation, transport and depositing of fill material shall be such that the fill is placed

in as uniform a mixture as practical. Each fill layer thickness should be such that the specified

compaction criteria can be achieved throughout the layer. The Contractor must demonstrate at the

Contractors cost that the specified compaction criteria are achieved using an approved supplier to

perform compaction tests. Tests are to be representative of a specific layer in a specific location. Any

failure of test results will result in the reworking of fill back to a point at which a successful

compaction test result was achieved at the Contractor’s cost.

Before any loose layer of fill is compacted, the material and its moisture condition should be as

uniform as practicable throughout its depth.

The maximum particle size of any rocks or other lumps within the layer after compaction should not

exceed 100 mm.

If there is a delay in the placement of subsequent layers, previously accepted layers which have wetted

up or dried out, shall be tined, moisture conditioned and again compacted to the requirements of this

Specification.

Where fill is to be placed over wet or boggy areas, a heavy grade non-woven geotextile such as Bidim

A34 or equivalent shall be placed directly onto the prepared foundation. The Contractor shall include

in his lump sum tender price all costs associated with the supply and installation of the geotextile.

1.5.5 FILL MOISTURE CONTROL

Material to be used as fill shall be moisture conditioned as required to permit it to be compacted to

the criteria specified. Fill shall not be compacted at moisture content outside the limit of 5% of the

Standard Optimum Moisture Content (AS 1298.E1.1) without approval from the Consultant Engineer.

If the moisture content of the fill falls below the specified minimum, water should be added either on

the fill or in the cut/borrow areas before it is transported to the fill area. Water applied to the fill

should be finely sprayed and uniformly blended throughout the full depth of uncompacted material.

If the moisture content of the uncompacted fill is non-uniform, the material should be mixed to

provide a consistent moisture distribution. Care is needed to ensure that mixing or blending does not

produce segregation of the fill material.



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If the moisture content of material is above the specified maximum, drying of the material may be

accelerated by aeration or by blending with dry materials.

If rain is threatening or the site is to be left unattended, the surface of the fill shall be sealed with

rubber-tire or smooth-wheeled plant and graded to prevent ponding.

1.5.6 FILL COMPACTION

Each layer of fill shall be compacted as a systematic construction operation, using plant which is

specifically assigned to be compaction task and which tracks progressively across the surface of the

fill.

Fill batter faces shall be compacted as a separate operation, or alternatively overfilled and cut back.

The trimmed and compacted batter face should have a roughened surface.

Where compaction control testing shows the relative compaction of the fill to be below the specified

level, all material represented by the test or tests shall be further compacted to exceed the minimum

compaction requirements as confirmed by further testing, or be re-worked and then retested. The

Contractor will test the fill as required by the Engineer at the Contractor’s cost.

The surfaces of all fill layers shall be shaped to provide drainage and to prevent ponding which will

cause deterioration of previously compacted fill layers.

1.5.7 COMPACTION CRITERIA

Fill shall be compacted to a minimum dry density ratio of 98% Standard Proctor (AS1289.El.l) unless

otherwise specified, or shown on the Drawings. Testing shall be undertaken by the Contractor as

required by the Engineer, in accordance with the guidelines presented in AS3798, to confirm that the

fill has been compacted to these specified minimum criteria.

The achieved compaction may also be checked using a dynamic cone penetrometer (AS1289.F3.2),

but this will only be undertaken after a correlation between dry density ratio and penetration resistance

has been established for the particular site and for each of the typical materials encountered. Where a

dispute exists as to the achieved compaction, the results of direct measurements of dry density ration

(AS1289.E4 1) shall be deemed to apply.

The upper layer of filling immediately below road sub-grade level shall be compacted to a minimum

dry density ratio of 98% Standard Proctor. This may be carried out at the time of pavement

construction. The Contractor must allow in the lump sum tender price for compaction tests as required

by the Engineer.

All fill layers have to be compacted, tested and approved by the Engineer prior to filling upper

subsequent layers. Contractor to allow compaction testing at a rate of 1 test per 100m2 (10x10m grid).



HLKJacob Limited

2. PAVEMENT SUB-BASE

2.1 GENERAL

Base & Sub-Base Course are deemed to include supply, placing and compaction, trimming and

grading, and all preparation and maintenance up to sealing of the surface.

Before any Sub-Base Course laying commences the Contractor shall notify the Consultant Engineer

to inspect the sub-grade, as well as being tested by an independent soil Consultant (allowed for in the

Schedule). After approval by the Consultant Engineer, the Contractor may commence placing Sub-

Base Course.

Tests to check compliance with specification requirements shall be carried out on representative

samples of the aggregate selected from any portion of a stockpile or truck load. The size of a

representative sample shall be such that it shall weigh at least 25kg. The test results shall be submitted

to the Consultant Engineer for approval not less than 20 working days prior to use of the proposed

sub-base course materials.

2.2 MATERIALS

2.2.1 DESCRIPTION

This section covers the requirements for natural gravels, crushed gravels, sand, soft or ripped rock

and crushed rock including mixtures thereof for use as pavement base and sub-base. The

requirements relate to the properties of the product as supplied.

2.2.2 DEFINITIONS

(a) Natural Gravel

Gravel is a naturally occurring mixture of angular or rounded rock fragments substantially

retained on a 4.75mm AS sieve with or without finer material and all passing the 75mm AS

sieve. It includes gravels screened to remove oversize fragments.

(b) Crushed Gravels

Crushed gravel is natural gravel, normally river gravel which is crushed to provide close

tolerances on grading.

(c) Sand

Sand is a product of rock weathering substantially passing a 4.75mm AS sieve and is

generally siliceous and free from appreciable quantities of clay and silt.

(d) Soft or Ripped Rock

Soft or ripped rock is rock extracted from a deposit without blasting and not requiring

processing through a crusher for reduction in size.

(e) Crushed Rock



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Crushed rock consists of crushed rock fragments manufactured from hard rock spalls which

are won by ripping or blasting from a solid rock face.

2.2.3 EXTRACTION

The quarry or pit shall be worked in such a way as to ensure that unsuitable material is not included

in the material supplied.

For production of base course crushed rock both the primary and secondary crushers shall be provided

with scalping screens to ensure that any remaining overburden is removed from material supplied to

the crushers.

2.2.4 SOURCE ROCK

Sedimentary source rock shall not be used for production of crushed rock base course material.

Igneous of metamorphic rock shall have a Los Angeles Abrasion Loss complying with the relevant

requirements of Table 2.2.1.

Table 2.2.1

ROCK TYPE LOS ANGELES ABRASION LOSS

(MAX0

BASE SUB-BASE

Granite 40 45

Granodiorite 40 45

Basaltic Rocks 30 35

Hornfels 25 25

Quartzite 30 35

If a source rock is to be used other than the type listed above, the Consultant Engineer will determine

whether the rock type is acceptable and will set appropriate limits

Source rock which does not comply with the specified requirements but from which crushed rock of

satisfactory performance has been produced, may be accepted for use subject to the written approval

of the Consultant Engineer.

2.2.5 PRODUCT

Pavement materials shall be free from vegetable matter, lumps or balls of clay or other deleterious

matter.

Natural gravels, sands and soft or ripped rock shall comply with the requirements of Table 2.2.2



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Table 2.2.2

PROPERTY BASE SUB-BASE

Liquid Limit % (Max)

Plasticity Index (Min)

(Max)

California Bearing Ratio % (Min)

Texas Ball Mill

35

2*

8*

60

45

40

2

12

25

-

* For unsealed pavements the minimum PI shall be 4 and maximum 10.

For crushed gravels and crushed rock the product shall comply with the properties shown in Table 2.2.3.

Table 2.2.3

PROPERTY BASE SUB-BASE

Sand Equivalent 45sec (Min)

Liquid Limit (% Max)

Plasticity Index (Max)

California Bearing Ratio % (Min)

50

30

6*

60

-

40

12

25

*For unsealed pavements the minimum PI shall be 4 and maximum 10.

For gravels, sands and soft or ripped rock, the product grading shall comply with the broad

requirements shown in Table 2.2.4. The Consultant Engineer shall provide a set of detailed grading

limits. Material supplied shall conform with these grading limits.



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Table 2.2.4

SIEVE SIZE AS MM % Passing by Mass

BASE SUB-BASE

150

75

37.5

2.36

0.075

100

100

98

15-40

2-12

100

95

-

12-45

2-10

For crushed gravels and crushed rock the product grading shall comply with the requirements shown in

Table 2.2.5 and 2.2.6.

Table 2.2.5 - Grading Requirements for Crushed 20mm and 40mm Base

SIEVE SIZE MM 20MM BASE 40MM BASE

TARGET

GRADING

LIMITS OF

GRADING

% PASSING

TARGET

GRADING

LIMITS OF

GRADING

% PASSING

37.5

26.5

19.0

9.5

4.75

2.36

0.425

0.075

-

100

100

73

54

38

16

4

-

-

95-100

63-83

44-64

29-48

12-21

1-7

100

85

74

54

39

28

11

3

95-100

80- 90

66- 82

44- 64

29- 49

22- 35

8- 13

2- 5

Table 2.2.6 - Grading Requirements for Crushed Sub-Base

SIEVE SIZE AS MM

LIMITS OF GRADING - %

PASSING

NOMINAL SIZE MM

50 40

75.0

53.0

19.0

0.425

0.075

100

-

54-75

7-21

2-10

-

100

64-90

7-13

2-12



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The crushed rock shall not be graded from near the coarse limit on one sieve to near the fine limit on the

following sieve or vice versa.

2.2.6 WATER

Where it is specified that water is to be added to the material prior to delivery, such water shall be clear

and substantially free from detrimental impurities such as oils, salts, acids, alkalis and vegetable

substances.

2.3 CONFORMITY WITH DRAWINGS

Base and sub-base pavement courses, each consisting of one or more layers, shall be finished to

reasonably smooth and uniform surfaces and after compaction shall conform within the following limits

to the levels, lines, grades, thicknesses and cross sections shown on the drawings or specified or directed

by the Consultant Engineer.

(a) Level

The level of the top of each pavement course shall not differ from the specified level by more

than 5 mm.

(b) Thickness

The thickness of the sub-base course at any point shall be not less than the specified thickness

by more than 5 mm and where the sub-base consists of two or more layers the thickness of

the top layer at any point shall be not less than that specified by more than 5mm.

(c) Shape

No point on the surface of each layer of base or sub-base shall lie more than 6 mm below a

3m straight-edge.

2.4 SPREADING

Spreading shall include running material from delivery vehicles and, as necessary, breaking to size,

mixing and watering to produce material of uniform appearance in the roadbed.

Each layer shall be spread and compacted as soon as practical after the previous layer has been

compacted and has been approved by the Consultant Engineer. The previous layer shall be kept in

good condition during spreading of the layer. Until compaction has been completed and approval has

been given, no further material shall be spread.

Soft or ripped rock shall be broken to a size not exceeding 60 mm and the layer brought to shape

before compaction begins.

Care shall be taken to minimize segregation of material. If segregation occurs the segregated material

shall be mixed and re-spread.



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Unless otherwise specified or shown on the drawings, the compacted thickness of any layer of any

course shall not exceed 150 mm.

Sub-Base and Base Course shall be compacted to 98% of Standard Proctor MDD.

2.5 TEST ROLLING

Pavement layers shall be compacted so that they are capable of withstanding, without visible

deformation or springing, test rolling with either a smooth wheeled roller of mass not less than 12

tonnes and with a load intensity on the rear wheels of not less than 6 tonnes per metre of width or a

pneumatic tyred roller having tyres inflated to 700 kPa and being loaded to not less than 4.5 tonnes

per tyre.

Test rolling shall be carried out to the approval of the Consultant Engineer prior to the placing of the next

layer of pavement material. The final layer should be test rolled immediately following completion of

compaction, but if test rolled at some later date, the entire surface shall be watered and given not less than

eight coverages of the testing roller before the test rolling commences.

Prior to sealing if required by the Consultant Engineer, the pavement strength shall be further checked

by means of defection tests using Benkleman Beam and to PWD requirements. Cost for these tests

is allowed for under the Provisional Sum in the Schedule of Prices. The Contractor must allow in the

lump sum tender price for compaction tests as required by the Engineer.

2.6 PROTECTION OF COMPACTED LAYERS

The surface of any compacted layer shall be kept sufficiently moist to maintain approximately the

appropriate optimum moisture content in that layer until succeeding layer is placed or until any

subsequent pavement works are commenced. Except where a pavement is being constructed under

traffic, construction or other traffic shall not use a compacted layer of pavement without that approval of

the Consultant Engineer. The pavement shall be kept in good order and condition by grading and rolling

and kept free of contamination.



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3. STORMWATER DRAINS

3.1 SCOPE

This specification covers the materials to be supplied and the work to be done in the construction of

stormwater drains. The work comprises the construction of stormwater manholes, culverts, precast invert

drains, rocklining, headwall and outfall structures.

LOCAL / NATIONAL AUTHORITY APPROVALS: The contractor is responsible for liaison with

local / national authorities to secure appropriate permits and approvals for construction of new

drainage works.

Any proposal by the Contractor to use alternative materials or manufacturers to that specified or

previously approved shall be accompanied, as a minimum, by a sample, relevant technical

documentation and test data to substantiate its suitability. Alternative materials or a change in the

source of supply of prime materials shall not be incorporated into the Works without the Consulting

Engineer’s written agreement.

AS 1460 Fittings for use with polyethylene pipes

AS 2033 Installation of polyethylene pipe systems

AS 4130 (Int) PE Pipes, pressure applications

AS 4131 (Int) PE Pipe compounds

BS 2494 Elastomeric joint rings for pipework and pipelines.

BS 8301 Building drainage.

BS EN295 Vitrified clay pipes and fittings and pipe joints for drains and sewers

NZS 3107 Precast concrete drainage and pressure pipes

NZS 3108 Concrete production - ordinary grade

NZS 3302 Ceramic pipes, fittings and joints

NZS 4404 Urban Land Subdivision

NZS 4452 Construction of underground pipe sewers and drains

Department of Labour, Occupational Safety and Health Service - Approved Code of Practice for

Safety in Excavation and Shafts for Foundations.

DOCUMENTS LISTED above and cited in the following clauses are part of this specification and

are the latest edition, including amendments at the time of tender. However this specification takes

precedence when it is of a higher standard than the cited document.

DRAINLAYER QUALIFICATION: Carry out all drainage with competent experienced tradesmen

under the direct supervision of a drain layer registered or licensed under the appropriate National

regulations acts or statutes.

3.2 PIPES

UPVC: UPVC pipes and fittings to NZS 7648.

CONCRETE: Precast concrete to NZS 3107.



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JOINTS: Flexible spigot and socket joints to BS 2494.

3.3 COMPONENTS - CESSPITS, MANHOLES

CESSPITS AND SURFACE WATER SUMPS: Precast concrete complete with lift-up cast iron grate

and frame.

MANHOLES: Circular precast components.

3.4 MATERIALS

3.4.1 PIPES & PRECAST REINFORCED OPEN CONCRETE BOX CULVERTS INCLUDING

ACO DRAINS

Pipes shall be flush jointed reinforced concrete, and shall comply with AS 1342 or equivalent, to the

Classes.

Precast reinforced concrete open box culverts up to 1200mm x 900mm shall comply with the

requirements of AS 1597 Part 1 including ACO Drains.

Any materials shall be first class quality and any defective materials shall be removed from site.

3.4.2 CONCRETE

Concrete used on the work shall be manufactured in accordance with NZS 1900 Chapter 9, 3A:1970

including all amendments and revisions.

Concrete used for encasing and capping culverts, open drains, headwalls and outfall structures shall

be ordinary grade concrete. Minimum strength shall be 25MPa for manholes, slab and similar

structures and 17.5MPa for scour stop.

Concrete supplied from recognized pre-mix concrete suppliers may be used but delivery dockets

which shall show the grade of concrete and its certified strength shall be retained and produced if the

Consultant Engineer calls for same.

3.4.3 CEMENT

Cement used for site mixed concrete, mortar and lean mix bedding and haunching shall comply with

NZS 3172:1974 for Portland cement. It shall be stored in a damp-proof shed. Any cement that is

lumpy or affected by moisture must be removed from the site.

3.4.4 REINFORCING RODS

Shall be of clean, deformed, round mild steel complying with NZS 3402P:1973.



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3.4.5 MORTAR

Shall consist of one part cement to two parts sand thoroughly mixed with water to form a paste of a

consistency suitable for the particular purpose. Only freshly made mortar shall be used.

"Reworking" of mortar shall not be permitted and such mortar shall be disposed of.

3.5 CONSTRUCTION OF ALL CAST IN-SITU ITEMS

3.5.1 PLACING CONCRETE

The concrete shall be worked with suitable tools when placed in the boxing to ensure maximum

density and a smooth surface without form marks. The segregation of the larger stones shall be

prevented by spading out the concrete to a flat slope. Any honeycomb or defects appearing on the

surface shall be remedied as directed by the Consultant Engineer immediately the boxing is removed.

Only freshly mixed concrete shall be used. Special attention shall be given to this point especially in

warm weather, when the setting of cement is considerably accelerated. Any concrete which shows

signs of initial setting will be condemned and shall be removed from the site of the work immediately.

Under no circumstances shall more than twenty minutes elapse between the time of mixing and

the time of placing or using of the concrete. Retempering of concrete, that is, mixing with water after

it has partially set, will not be permitted.

3.5.2 BOXING

Approved steel forms and moulds may be used in lieu of timber boxing. Timber for boxing where

supporting exposed surface shall be thickened and dressed smooth on one surface and both edges and

the boxing when built shall be close jointed and grout tight. It shall be designed to be easily removable

without marring the green concrete. It shall be designed to be securely stayed to prevent displacement

and appreciable deflection. Before being used again all boxing will be thoroughly cleaned and treated

with soft soap or other approved material to prevent the concrete adhering. The boxing supporting

vertical faces shall not be removed for at least thirty six hours after the concrete is placed. The green

concrete shall be protected by a covering of damp sacks for at least a week after the concrete is placed.

3.6 EXCAVATION AND BACKFILLING

3.6.1 EXCAVATION

The excavation for the trenches shall be taken out in accordance with the longitudinal sections and

by open cut. The trench shall be of sufficient width to admit all operations necessary for the jointing

of pipes and placing of concrete to be carried out with freedom.

The sides, where necessary and required by law, shall be supported by suitable shoring placed so that

it shall not interfere with the work of pipe laying and jointing and concrete work.

The Contractor shall observe the provision of the "Construction Act 1959" and any amendments

which may be made thereto and section 1.16 of this specification.



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3.6.2 BACKFILLING

All pipes shall bear evenly on the bedding along the whole length of the barrel. No backfilling shall

commence until the pipes have been inspected and passed. The first layer of backfilling shall compose

clean stone-free soil, and extend to 150mm over the top of the pipe and shall be thoroughly

compacted, except where pipes are concrete capped or encased.

3.6.3 SUBSOIL WATER

Should subsoil water appear in the trenches it must be kept down below the level of the bottom of the

concrete or the joints, until the concrete is thoroughly set. For this purpose the Contractor shall

provide and use in the work all necessary pumping facilities, so positioned that they do not interfere

with the bedding, laying or jointing the pipes. All costs, whatsoever, in connection with keeping the

subsoil water down to be borne by the Contractor. Should the Contractor fail to take adequate steps

to keep the water down, or should the Consultant Engineer consider the methods adopted by the

Contractor are endangering or damaging the foundations of the sewers, the Consultant Engineer shall

have the power to order the Contractor to adopt other methods. Under no circumstances shall any

water be allowed to drain into the existing sewers. The Contractor shall not permit any pump to

discharge onto the roadway.

The above will also apply to sea water ingrest. The contractor shall manage his time to work when

the tide is low if the water is unable to be pumped out of the trench.

3.7 PIPE LAYING PROCEDURE

3.7.1 BEDDING

Pipes shall be laid on clean sand or other approved granule material. Bedding layer shall be 200mm

minimum under the pipe barrel and sockets.

Precast slabs shall be laid on a 50 mm thick bed of concrete of minimum strength 15MPa. The

concrete bed shall be formed on top of a clean and even surface, any weak areas shall be removed

and replaced by clean fill and properly compacted as directed by the Consultant Engineer.

3.7.2 LAYING

Only competent approved drain layers will be allowed to lay the pipes which must be laid with the

greatest possible accuracy as to line and levels. Proper sight bars and boning rods shall be used for

this purpose.Pipes shall be laid at the low end and proceed upstream unless permitted by the

Consultant Engineer. No pipe laying or bedding shall be commenced until the trench foundations

have been inspected and passed by the Consultant Engineer.

Should the Contractor excavate to a greater depth than required, such space must be filled with

basecourse material at the Contractor's expense. Trenching and bedding must be done in at least 4m

lengths, and the bedding well banked up the sides as shown on the detail drawings.

All joints shall be mortared in watertight fashion on inside and outside faces.



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3.7.3 TESTING OF STORMWATER PIPES

All pipes will be inspected by means of a mirror and lamp to ensure correctness of line and grade.

Before backfilling the Consultant Engineer will inspect all joints and bedding.

Should there be any length or lengths of pipes which are not laid to the satisfaction of the Consultant

Engineer, notwithstanding that such may have already been inspected, such portions must be taken

up and re-laid and the cost of making good any damage done by breakages or otherwise in so doing

must be borne by the Contractor.

3.8 HEADWALLS AND OUTFALL STRUCTURES

Where headwalls and outfall structures in mass or reinforced concrete are required the concrete,

formwork etc, shall conform to the provision of Section 9 of this Specification.

3.8.1 EXCAVATION

General

All drains shall be excavated to the grades and levels shown on the Consultant Engineering Drawings.

Drains must be constructed so as to effectively collect surface water off roads and properties.

Drains

Drains, where shown on the drawings, shall have concrete invert units and rock pitched sides. Except

where excavated in in-situ soapstone the rock pitching shall be installed to 150mm lower than existing

or finished ground level.

Drains shall be excavated to the profile shown on the Drawings. Any over excavation shall be made

good, to the Consultant Engineer's satisfaction, at the Contractor's cost.

3.8.2 LAYING

Precast Concrete ACO Drains

Refer to manufacturers requirements. ACO drains shall be laid true to level and grade and jointed as

detailed. The units must be supported for their full length and not span between concrete joints.

The gap between units shall not exceed 50mm and the concrete bank shall be placed so as to ensure

optimum penetration of concrete. The jointing concrete must be fully cured before water is permitted to

flow through the drains.

Any over-excavation beneath the inverts shall be made up with compaction, approved granular material

- or lean mix concrete - at the Contractor's expense.

Stone Pitching

Stone pitching is required for drain lining, at culvert entrances and exists, at changes of direction of drains

and for outfalls.



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Wherever used, the individual stones must be thoroughly bedded in concrete or mortar. The exposed

surface must be as smooth as possible to allow good flow conditions.

The practice of dry packing and pointing rocks is not acceptable.

50mm dia uPVC weepholes must be provided for every 1m2 facing of all stone pitching and located

immediately above the top of the pre-cast invert. These holes should be staggered where necessary.

Stormwater Manholes

Concrete formwork and reinforcing shall comply with Section 9 of this Specification.

Pipes shall be carefully cast into the walls of the pits at the correct levels and in a watertight fashion. The

bottom shall be carefully shaped to ensure complete discharge of water.

3.9 DRAINAGE TRENCHES AT BASE OF RETAINING WALLS

3.9.1 DRAINAGE TRENCH:

The drainage trench shall be sufficiently deep that the top of the pipe will be not less than 0.45m

below the top of the trench and shall be not wider than 0.6m. The base of the trench shall be

constructed so that there is a uniform fall 1:`150, without apparent high or low areas which may

impede the efficient drainage of collected water.

3.9.2 DRAINAGE PIPE

The drainage pipe shall be an approved flexible slotted PVC pipe of 100 mm.

Joins in the pipe shall be made in accordance with the manufacturers recommendations and be such

that an unimpeded flow of water can occur through the joins. The joins shall be wrapped in an

approved non -woven geotextile.

3.9.3 TRENCH BACKFILL

Trench backfill shall comprise crushed rock or run of pit river gravel, containing not more than 5%

dry weight of material finer than 0.075 mm, and generally be uniformly graded with particle sizes

between 5 mm to l5rnm. The maximum particle size up to 150 mm above the pipe shall be 10 mm.

The balance of the backfill may have a maximum particle size of up to 25 mm.

A 25 kg sample of each of the proposed trench backfill materials shall be submitted to the Consultant

Engineer for approval not less than l0 working days before it is planned to place trench backfill.

Stockpiling or use of any material on site before this approval is given will be entirely at the

Contractor's risk. After approval is given for the use of a particular material, the Contractor shall

ensure all material delivered conforms to the general particle size distribution and quality of the

sample submitted for approval. The Consultant Engineer may undertake checks on material being

delivered to assess conformance with the approved sample(s).



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3.9.4 CONSTRUCTION

Crushed rock or run of pit gravel shall be wrapped with filter fabric. The filter fabric shall be Bidum

A24 or equivalent unless otherwise noted on the drawings.

A bedding layer not more than 25 mm thick of 10 mm maximum size trench backfill material shall

be placed in the base of the trench. The drainage pipe shall then be placed on this initial layer joined

as required, and carefully covered with further backfill to achieve a minimum cover of 10 mm over

the pipe. This layer shall then be lightly compacted taking care not to damage the pipe. The balance

of the backfill may then be placed in the layers nor greater than 300 mm loose thickness and

compacted. The trench backfill material should extend not less than 150 mm above the top of the

trench, over a width equal to twice the width of the trench. Filter fabric shall cover the top of the

trench backfill with a 200 mm minimum overlap.



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4. CONCRETE, FORMWORK AND REINFORCEMENT

FOR PAVEMENT

4.1 SCOPE

This chapter is a general specification only. More specific details are included within the descriptions of

each major unit of construction elsewhere in this specification.

4.2 MATERIALS

The specification shall be read together with the following New Zealand Standard Specifications:

a) NZS 3122:1974 Portland Cement (ordinary and rapid hardening)

b) NZS 3112:1974 Methods for Testing of Concrete

c) NZS 3111 & 3121 Concrete Materials and Methods of Test

d) NZS 3101 Reinforced Concrete Design

e) NZS 1900 Chapter 9, Division 9-3A Concrete

If ready mixed concrete is used, the handbook of the New Zealand Ready Mixed Concrete Association

Inc., for the Grading Scheme Covering Classification of Plants, shall also be read with this specification.

Items in the Schedule of Prices allow for the building-in to concrete of various components. However,

these items are not limiting and the Contractor shall ensure that all components necessary are built into

the concrete.

Materials shall be water and aggregate to NZS 3111, and 3121, with maximum stone size of coarse

aggregate of 20mm and ordinary Portland cement to NZS 3122.

All concrete shall comply (as a minimum standard) with the requirements for High Grade Concrete -

Clause 9.3A17 of NZS 1900.

Minimum cement content = 360 Kf/m3

Maximum water/cement ratio = 0.52 by weight

Note: Some variation of these proportions may be considered by the Consultant Engineer provided

evidence is produced in support of such variation and is to the satisfaction of the Consultant Engineer.

Workability of the concrete density and the ability to take a high surface finish as well as strength are all

factors of significance for concrete incorporated in the works of this contract.



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With a view to limiting shrinkage particularly in floor slabs, concrete mixed to the requirements of

Special Grade Concrete - Clause 9.3A18.1 NZS 1900 (which permits the use of less cement and hence,

for the same workability and strength, less water) is preferred.

Concrete used (except site concrete) shall attain a 30MPa crushing strength based on a standard 300mm

x 160mm cylinder at 28 days unless otherwise specified.

It is preferred that all concrete is produced by a ready mix plant, and it is further preferred that this plant

has a Special Grading in terms of the N.Z.R.M.C.A Grading Scheme. The Consultant Engineer at his

discretion may not accept any concrete produced by an ungraded ready mix plant. Alternatively, an

approved weigh batching plant may be established on the site and operated (as a minimum standard) to

the requirements of Clause 9.3A.17 NZS 1900. In this case, mixers shall comply with the requirements

of the NZS 3105, Batch Type Concrete mixers.

Records shall be kept and tests taken as specified in the Grading Scheme and NZS 1900 and these results

shall be kept and made available to the Consultant Engineer as required. The Consultant Engineer shall

require certificates of test from a competent authority for all concrete materials before manufacture

commences and may require additional tests from time to time as the work proceeds. In addition to the

minimum number of compression tests required in both Clause 7(c) of the Grading Scheme (i.e. two sets

per day or one set every forty batches), the Consultant Engineer may require further compression tests

to be carried out.

The cost of carrying out all routine and control testing and preparing all records and of producing initial

test certificates for all materials shall be borne by the Contractor and he shall allow for such costs. Tests

on concrete shall be conducted in accordance with NZS 3112. Methods for the Testing of Concrete, and

tests on cement and aggregate shall be in accordance with the appropriate specification.

The plastic concrete shall be sufficiently workable to permit placing and compacting by methods to be

approved (appropriate to the various situation in the works) so that the hardened concrete is dense and

has the required surface finish. Good workability shall, as much as possible, be achieved without the

excessive use of water.

Excessive bleeding of the placed concrete must also be prevented.

No admixtures of any kind, including air entraining agents and pozolans shall be used without the written

permission of the Consultant Engineer. Their use, although not favored, will, however, be considered at

the Contractor's expense. Mixing shall be carried out in accordance with the requirements of the Grading

Scheme (for central or transit mixers) and NZS 1900.

Concrete shall be handled and placed in accordance with Clauses 9.3 A.20, 9.3 A.28, and A.29, of NZS

1900.

The Contractor shall advise the Consultant Engineer in advance of the methods he proposes to employ

to place concrete in the various parts of the work. The Contractor shall decide before tendering, by

inspecting the site and drawings, methods he shall employ for placing concrete in the various situations

and shall allow for this in his scheduled rates for concrete. Segregation of concrete during placement

will be cause for rejection of the method by the Consultant Engineer and the cessation of operations.



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Transporting and placing plastic concrete by means of pumping techniques will be accepted as a method

of placing provided approved equipment is employed and all other criteria in respect of concrete strength,

mix design, placing, density, finish etc., are met.

All concrete shall be thoroughly compacted during and immediately after depositing, by means of

approved power driven vibrators of size suitable for the section being poured.

Frequencies under load shall range between 4,000 and 8,000 cycles per minute, depending on the unit

used which should normally be of the "internal" or "spud" type. The use of a vibrating screed may be

considered for slabs.

Operators shall be competent and dependable.

Vibrations shall not be used to produce lateral motion of concrete but shall be concentrated in causing

vertical settlement and consolidation. Care shall be observed to ensure that zones of vibration overlap

and that no portions are missed. Vibrating elements in continuous operation shall be slowly inserted and

withdrawn from the concrete mass at distances apart not exceeding 600mm or the radius over which

vibration is visibly effective.

Vibration shall not be transmitted through boxing or reinforcing to concrete which has taken its initial

set. The vibrating element shall be used in such a way as not to displace reinforcing steel or damage the

internal faces of boxing by contact therewith. Vibration shall be continued until the concrete becomes

uniformly plastic, an indication of this being the appearance of a visible line of cement paste at the

junction of the concrete with forms and reinforcing steel, or the forming of a level top surface with just

enough mortar for finishing.

The vibrating head shall be removed from the concrete when this stage is reached.

The formation of pools of grout or areas of segregation by over-abrasion will not be permitted. Removal

of vibrating tools shall be made slowly to prevent the formation of voids. The formation of air bubbles

against vertical formwork or faces sloping back towards the concrete shall be obviated by lightly

vibrating as closely as possible to the forms without damaging them, supplemented by the use of hand

spading and slicing tools along the forms.

A spare vibrator must be available at all times when concreting.

Where a placing diagram is included in the drawings, construction joints shall be located only where

indicated. In the absence of a placing diagram, construction joints shall be located only where directed

or approved by the Consultant Engineer.

In general, construction joints shall be avoided as much as possible.

Wherever practicable, each particular part of the structure shall be concreted in one continuous operation.

Construction joints shall be formed as shown on the drawings or where not specifically detailed shall be

perpendicular to the axis of the member.



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Joints shall be formed perpendicular to the finished faces of the structure and feather-edges avoided,

unless detailed otherwise.

Vertical or stepped joints shall be properly boxed with close fitting formwork. At the horizontal joints

on exposed faces, temporary beading shall be fixed inside the forms to ensure straight lines on the outer

edges of the joints.

Immediately prior to concreting forms shall be re-tightened near construction joints to prevent mortar

escaping and flowing over the faces of preceding lifts of concrete.

Horizontal and vertical construction joints shall only be made where necessary and where approved by

the Consultant Engineer. All horizontal and vertical construction joints shall be provided in the following

fashion.

Horizontal: Bring the concrete surface to a level, horizontal line and vibrate carefully, apply an

appropriate retarding agent to the concrete surface while still wet and hose off the following day to

produce a dense, exposed aggregate surface.

Vertical: Apply an appropriate retarding agent to the stop-end formwork immediately, or as soon as

possible before placing the concrete. Remove the stop-end the following day and expose the aggregate

on the concrete face by jetting with water.

In general, no further treatment will be required on construction joints, but in specific instances provision

of a water stop section may be required.

At the time of placing concrete against construction joints, the joint shall be thoroughly damp but without

free water. It will not be satisfactory simply to wet dry concrete immediately prior to concreting.

Curing shall be in accordance with Clause 9.3 A.28.9 NZS 1900 and curing membrane compounds shall

not be used. In hot weather, concrete (particularly slabs) shall be covered as soon as possible after

hardening and kept wet. Provision must be made for keeping concrete wet in weekends and outside

normal working hours.

4.3 FORMWORK

The Contractor shall allow in his prices for those items all associated materials and work involved, such

as falsework and erection, cleaning, coating and dismantling and any other materials or work necessary.

All formwork shall be in accordance with Clause 9.3 A.31 NZS 1900 and shall be constructed in such a

manner and of suitable materials to ensure the production of the surface finish specified. Only approved

ties and spacers shall be used on wall forms.

Forms shall be designed so that the deflection of sheathing shall not exceed 1/200 of the span between

joists or other supports and in any case shall not exceed 3mm.

The methods of construction shall be such that vertical surfaces can be stripped without disturbing the

boxing or supports to beam, slab, or arch soffits, which require to be left in place for a longer period.



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Forms for high sections such as walls shall have one side left open, which shall be closed progressively

as concreting advances, but at no stage to a height exceeding 1.200m above the layer of concrete being

placed.

Forms shall be filleted or chamfered at all sharp corners, and shall be given a slight bevel at all projections

to ensure easy removal without damage to the concrete.

Bolts, and other metal fittings used in formwork erection, shall be constructed so as to permit their easy

removal to a depth of at least 50mm from the face without injury to the concrete and so that upon their

removal the cavities left are of the smallest possible size. Forms may be re-used, subject to the approval

of the Consultant Engineer, and provided they still satisfy the above requirements.

Surface of re-used forms which are to come in contact with concrete shall be thoroughly cleaned before

erection.

The inside surface of all forms shall be given a coat of approved material which shall not stain or adhere

to the concrete, or shall be saturated with water immediately before placing the concrete.

4.4 SURFACE FINISH

Surface finish of all surfaces both formed and unformed, interior and exterior must be of a uniform high

standard. Acceptable standards will be determined on test panels produced by the Contractor at the

commencement of the work. Reference should be made to the NZ Portland Cement Association

Publication A.C. 4 extracts from which have been included hereunder. The surface finish required for

all surfaces is shown on the drawing as a reference defined hereunder.

a) Unformed Surfaces

All surfaces formed without the use of formwork, e.g. floor slabs and pad and beam tops. The

reference to the standard of finish is prefixed by the letter U.

b) Formed Surfaces

Those resulting from the placing of concrete against formwork, e.g. walls, columns, upstands,

slabs, etc. In this case the reference is prefixed by the letter F.

c) Wood Flat Finish

Concrete floated after screeding but not until some stiffening has taken place in the surface of

the concrete and the moisture film has disappeared. Floating should work the concrete no more

than is necessary to produce a surface that is uniform in texture and free from screed marks.

d) Steel Trowelled

Finish U3

After placing concrete the surface is screeded flat and (when the moisture film has disappeared,

and the concrete hardened enough to prevent an excess of fine material and water from being

worked in the surface) trowelled by hand or by power driven machine.

e) Hard Steel Trowelled



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Finish U3

As above but with further trowelling when the surface is nearly hardened, using firm pressure

and trowelling until the surface is hard and has almost a glossy appearance.

NOTE:

Hair cracks and crazing are usually a result of a concentration of water and fines on the surface caused

by excessive trowelling before sufficient stiffening has taken place on the surface. Such cracking is

aggravated by too rapid drying or sudden cooling and care must be taken to avoid these effects.

f) Finish F1

Some surface roughness allowed, e.g. slight joint displacement, form marks, etc. Formwork

may be constructed of any material that will not leak mortar. Form tie holes must be filled.

g) Finish F2

Formwork must be of tongue and groove, dressed timber, plywood, steel or hardboard faced and

all joints must be grout tight. Treatment of surface after removal of forms includes filling all tie

holes and rubbing down fins and roughness.

h) Finish F3

Formwork as above, but must be skillfully fitted. All forms must be grout tight and joints must

be sealed with suitable sealing strips or compound. Surface treatment shall include removal of

any fins, filling of all tie holes and surface air holes to leave a surface which is smooth, true and

dense which will not offer any pockets or ledges where dirt and dust may accumulate.

Maximum Allowance of Irregularities in Concrete Surfaces

Unformed surfaces - measured from 3.0m template.

U2 6mm deviation

U3 and U3H 6mm deviation

Formed surfaces measured from a 1.5m template.

F1 25mm gradual deviation 12mm abrupt deviation



"Abrupt deviation" means offsets, etc., caused by displacement or misplacement of misplaced formwork.

"Gradual deviation" includes all other.

NOTE:

Mortar for filling tie holes, etc., shall be made from the same sand as used in the concrete being filled.

The sand must all pass a 5mm N.Z.S. sieve and should be mixed in the proportions one and half to two

parts sand to one part ordinary Portland cement by volume. Tie holes should be filled with a stiff mortar

and compacted by ramming or caulking with a suitable tool. Mortar should be cured for 3 days.



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Surface finishes of the various surfaces shall be as noted on the drawings. As a guide however, typical

finishes will be:

Hidden formed surfaces : F2

Exposed formed surfaces : F3

Most horizontal surfaces : U3

Particular horizontal surfaces : U3H

The Contractor shall allow in his lump sum tender price for achieving the Unformed surface finishes

specified.

4.5 REINFORCEMENT

Reinforcement shall conform tothe requirements of Clause 9.3 A.9 NZS 1900.

All 10mm, 12mm, 16mm, 20mm dia. bars shall be deformed high tensile steel (Grade 500).

Hooks shall only be provided where shown and shall be formed with an internal radius of not less

than that stated in 9.3 A.33.2 of NZS 1900, with a minimum extension beyond the curve of 4 bar

diameters.

Cover from concrete surface to reinforcement shall be accurately maintained as shown on the

drawings. All reinforcing steel shall be accurately placed in position as shown on the plans and during

the pouring and compacting of the concrete, shall be firmly held against displacement.Soft black iron

wire not thinner than 1.2mm nor thicker than 2.0mm shall be used for tying the reinforcing rods at

intersections. Ties shall be located at sufficiently close intervals to maintain the rods in their correct

positions.

Distances from the forms shall be maintained by means of stays, blocks, ties, hangers, or other

approved supports. Blocks for holding reinforcement from contact with the forms shall be clean

precast mortar blocks of approved mixture, shape and dimensions. Reinforcement in any members

shall be placed and then inspected and approved by the Consultant Engineer before the placing of

concrete begins.

Concrete placed in violation of this provision shall be liable to rejection and removal.

Provision shall be made for workmen to reach any part of the work without standing on reinforcement.

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