Pricing document ofadb - Forestry Commission · Pricing document ofadb = Client Name : ... Timber Truss Notes ... The design, fabrication and erection is to be in

Pricing document ofadb=Client Name : Forestry Commission

Project Title : Sherwood Pines Visitors Centre – Proposed WC Block

Project Nr : 141200

Appendix A

Tender Drawings

Structural Engineer Drawings and Specification

450wide Edge thickening




1400

thick

ening

450 thickening450 thickening450 thickening

500 t

hicke

ning

150thk. RC Raft Foundation

FOUNDATION PLAN1:100

800sq x 600dp

2

2

1 1

1

1

1

1

1 1

3 3

3

3

pad foundation

800sq x 600dppad foundation

B B

A A

TOF 150 below FFL

TOF 150 below FFL

4 4

4 4

300

450

450

FFL

Typical Section Through Floor Slab

1200g DPM

25mm sand blindingMin. 150mm thk. compacted Type 1 DOT sub-base.

1No Layer BS ref: A142 fabricin bottom face - 35mm cover

150mm thk. r.c. slab. Concrete to be a designated mix RC30in accordance with BS 8500

1:20

(400mm min. laps)

35

Screed / insulation over to Architects details

Formation to be proof rolled.

1No Layer A142 fabric

1400

300

450

300

25mm sand blinding

Section 1-11:20

Section 2-21:20

Section 3-31:20

150x150 Oak post

stub with 100x150x8thk. fin plate

150

FFLFFL FFL 150

150

100x100x4SHS galvanised

through bolted with 4M16 bolts to timber post

300x300x12thk baseplatewith 4M12 HIT-V 5.8 boltswith HIT-HY200A resin by Hilti - 70mm embedment.

200

600m

in tbc

on si

te

800

Section 4-41:20

Typical drains below slab thickenings to be surrounded in concrete

to Architects details.Brick coping & handrailing

bricks to be F2/S2 with min. strenght of 20N/mm2 to be laid in M2 (i) mortar.

One brick thick wall construction

Ramp Retaining Wall(1:20)

Extg Ground level

Foundation concrete to be a designated mix Gen 3

Min.

450

600

Foundation concrete to be a designated mix Gen 3

Formation to be onto firmnatural ground, to be confirmed on site.

Typical Section thro' External

215

150

525

328

FFL 91.500

Fill from Site Arisings

Exisitng ground profile


FFL 91.500


Fill from Site Arisings

SECTION A-A1:50

SECTION B-B1:50


Proposed grd level

Proposed grd level

Suitable site arising's compactedin accordance with Earthworks Specification

TENDER ISSUE

General Notes

Risk / Hazard or Works Denotes Significant Residual

Existing below/ above ground servicesexist, Contractor to undertake radar scan

Required to Mitigate Risk*

1

composition to external face of concrete Two coats of RIW liquid asphaltic

surround where 100mm cover to steelwork

This drawing to be read in conjunction with all relevant Architect's and Engineer's drawings and specifications.

refer to Architects details and specifications.For details of dpm, dpc & insulation

Unsuitable materials i.e.- topsoil, blacktop and blacktop plainings to be removed frombelow the areas of ground floor slab and replaced with Type 1 DOT compacted in maximum 150mm layers. Any localised

Foundation concrete to be a designated mix RC 30 in accordance with BS 8500.

pockets also to be removed and filled.

01.

04.

03.

05.

02.

cannot be achieved.

CHECKEDDATEREF REVISION

DRAWN

XREF FILE REFERENCE:

FILE REFERENCE:

DRG NO REV

CHECKED BY

DRAWING

PROJECT

CLIENT

SCALE @A1 DRAWN BYDATE

TEL:

FAX:

www.ridge.co.uk

FOUNDATIONS

SHERWOOD PINES

TOILET BLOCK

FORESTRY COMMISION

141200-S-01

As shown 09/14 ARM ARM

ARM

2 CRANBROOK WAY

SOLIHULL BUSINESS PARK

SOLIHULL

B90 4GT

0121 713 8000

01993 815006

-

prior to excavating.

152x89x16 UB152x89x16 UB

152x89x16 UB

Timber Attic trussed rafters at max 600mm c/c.

Timber trussedrafters at max600mm c/c.

A

A

Roof Plan1:100

1

1

2 2

3

3

152x89x16 UB100mmbearings

PS PS PS

2No.

203x

102x

23 U

B20

0mm

bear

ings

150x150 oak post

150x150 oak post

250x200 oak beam100mm bearings

4

4

Denotes internal wall to support roof trusses.Denotes 215x100x150 dp. concrete padstone.PS

5 5


3

3

1

1

Timber trussed rafters to specialist's design & details.

100 t

hk. b

lockw

ork

100 t

hk. b

lockw

ork

Section A-A1:50

plate using BAT truss clips.Trusses secured to wall

to wall. (Similar to Section 1-1)strap plugged and screwedmild steel vertical restraint

100x63 dp timber wall platebedded on mortar. Galvanised

Ground Floor Plan1:100

Denotes contraction jointin blockworkCJ

CJ

CJ

CJ

CJ

CJ

CJ

CJ

CJ

CJ

CJ CJCJ

CJ

CJ CJ CJ

CJ

CJCJ CJ

CJ CJCJ

L3

2No.

203x

102x

23 U

B20

0mm

bear

ings

L5

L6

L3

L3 L3L3

L3L3

L3L3

L4

L4

L1L1

L1

L1

L1

L1

L2

L2

150x150 oak post



sheradised nails through 30mm long square twisted fixed using BAT 3.75 x plate using BAT truss clipsTrusses secured to wall

(Straps at 1200 max. crs.)

wall using five No.12 x 50mmstrap plugged and screwed tomild steel vertical restraint30x2.5mm thk. galvanised

long wood screws.

100x63 dp timber wall platebedded on mortar.

150

Section 1-11:20

Section 3-31:20

2/47x150 grade C16 timbersbolted together with M12bolts at 600mm c/c.100x100 grade C16 timberposts at approx. 1m c/c tosuit window spacing.100x63 dp timber wall platebedded on mortar.

(Straps at 1200 max. crs.)

wall using five No.12 x 50mmstrap plugged and screwed tomild steel vertical restraint30x2.5mm thk. galvanised

long wood screws.

Expametframinganchors

150

Section 4-41:20

raftersTrussed

block.over uncutStrap fixed

Bottom chord

AB

CNoteNoggings fixedhorizontally.

NoteSpacing of straps not to exceed 1.2m

=C

=B

A =

(max) centres fixed over 3No. horizontal restraint straps at 1200 30x5mm thk. Galvanised mild steel

38x100 Timber noggings at strap

wall and truss at strap position. Solid timber packing between

C

(Packing to be securely fixed to truss)

position.

trusses using 3.35 x 75mm long round wire nails.

B

Section 5-51:20

raftersTrussed


A


B

250x200 oak beam

Truss clip as Section 1-1

150

150

raftersTrussed


Bottom chord

A

A

B


NoteSpacing of straps not to exceed 1.2m

=C

=B

A =

(max) centres fixed over 3No. horizontal restraint straps at 1200 30x5mm thk. Galvanised mild steel

38x100 Timber noggings at strap

wall and truss at strap position. Solid timber packing between

150

150

C

(Packing to be securely fixed to truss)

position.

trusses using 3.35 x 75mm long round wire nails.

B

Section 2-21:20

Truss clip as Section 1-1

225 2251 3 4 1

Typical Contraction

1:20(CJ) Joint Detail

2

Typical Detail atDoor/Window Opening

150

1:20

Wall Tie Legend

3

1

=

= Type 2 Stainless steel cavity wall ties to PD6697 : 2010 x 225mm long at 450mm vertical spacings. (Ancon ref: RT2)

(Joint sealed / finish to Architect's detail)10mm compressible joint filler

As 1 but at 225mm vertical spacings.

=4

sleeve over half its length) at 450mm vertical spacings. 20x2.5mm stainless steel flat ties x 225mm long (with debonding

(Note: debonding sleeve pulled back 10mm to allow both contraction and expansion of the masonry) (Ancon ref: PPS)

2 =

Typical Internal WallJunction Detail

45

1:20

=5at 450mm vertical spacings. 65 wide x 250 long galvanised expanded metal lathing

1

Typical External

1:20Wall Detail

750

1

NoteTies at 450mm vertical and 750mmhorizontal staggered spacing.

830/844L1

Ref. span Description No.

6

LINTEL SCHEDULE

Steel lintels to be propped during construction.

100w x 70 dp. PCC Lintel

Lintel Clear

Lintels to have min. 150mm bearings.

by Naylor Lintels. ref: P100. Length = 1100mm

1000L2 2100w x 70 dp. PCC Lintel by Naylor Lintels. ref: P100. Length = 1200mm

1000/1050L3 9L1/S 100 Cavity Wall Lintel by IG LintelsLength = 1350mm

2225L4 2Length = 2550mm

1606L5 1L1/S 100 Cavity Wall Lintel by IG LintelsLength = 1950mm

L1/S 100 Cavity Wall Lintel by IG LintelsL1/S 100 Cavity Wall Lintel by IG Lintels

L1/S 100 Cavity Wall Lintel by IG Lintels

L6 830100w x 110dp. PCC Lintel

Length = 1100mm1by Naylor Lintels. ref: S4.

CHECKEDDATEREF REVISION DRAWN


FILE REFERENCE:

DRG NO REV

CHECKED BY

DRAWING

PROJECT

CLIENT


TEL:

FAX:

www.ridge.co.uk

2 CRANBROOK WAY


SOLIHULL

B90 4GT

0121 713 8000

01993 815006

--- -

-

CHECKEDDATEREF REVISION DRAWN


FILE REFERENCE:

DRG NO REV

CHECKED BY

DRAWING

PROJECT

CLIENT


TEL:

FAX:

www.ridge.co.uk

SUPERSTRUCTURE DETAILS

SHERWOOD PINES

TOILET BLOCK

FORESTRY COMMISION

141200-S-02

As shown 09/14 DSS ARM

2 CRANBROOK WAY


SOLIHULL

B90 4GT

0121 713 8000

01993 815006

Winter and or (iii) in Summer. Class (iv) shall not be Mortar above and below DPC shall be class (i) or (ii) in

specification at 750mm horizontal x 450mm verticalsteel Type 2 to PD6697 : 2010 to Architects Unless noted otherwise cavity wall ties to be stainless

All ties to have a minimum embedment of 50mm into

Unless noted otherwise all blockwork to to have a minimum compressive strength of 7N/mm sq.

This drawing to be read in conjunction with all relevant Architect's and Engineer's drawings and B.H.P.Ltd's specifications.All steelwork to be Grade S275 to BS EN 10 025: 1993.

All steelwork within external wall to be painted with two coats of R.I.W. liquid asphaltic composition. (Refer to steelwork specification).

01.

02.

08.

Notes

unless noted otherwise.

09.

10.and specifications by others.For acoustic and thermal insulation refer to details

For corrosion protection to Steelwork refer to the Structural Steel specification. For finishes and fire protection refer to Architects details.

Unless noted otherwise all structural bolts, nuts & washers to be grade 8.8. and all welds to be6mm full profile fillet welds.

prior to fabrication.Setting out to be confirmed on site by Contractor For all setting out refer to Architect's details.

The Contractor shall fully survey all of the existing structure prior to fabrication.

zinc phosphate primer to a dry film thickness ofAll steelwork shall be blast cleaned and painted with

75 microns after fabrication.All damage to painted surfaces shall be made good on site to an equivalent standard to the above specification.

03.

04.

05.

06.

07.

For setting out of walling see Architect's details.

11. Unless noted otherwise all loose timbers to beGrade C16 and service class 1 in accordance withBS5268 : Part 2

used.

brick/blockwork.

staggered spacings.

12.

13.

14.

15.

16.

Timber Truss Notes This drawing to be read in conjunction with all relevant Architect's and Engineer's drawings and specifications.

01.

The design, fabrication and supply of all parts ofthe roof structure and fittings between top of wallplate and top of rafters is the responsibility of the

03.

All trussed rafter stability bracing by specialist - tobe in accordance with BS 5268.

05.

LoadingsWind loading to be in accordance with B.S. 6399-2.

06.

Imposed loading (Including snow) to be in accordance with B.S. 6399-3.

Dead Loads - As for specified materials.

Trussed rafters shall be spaced generally at 600crs. 07.

specialist supplier. Restraint straps between walls and the roof will be the responsibility of the General Contractor. The roof is defined on the relevant Architects drawings.

The design, fabrication and erection is to be inaccordance with BS 5268.

04.

but adjusted or doubled up to suit access holes and other requirements.

All fixings shall be compatible with the preservative08.treatment applied to the trusses.

Contractor designed elements.The contractor must submit to Ridgecalculations details and layouts for all contractor

02.

designed elements for approval prior to fabrication.

Attic Truss floor load = 5kN/m2

TENDER ISSUE

SPECIFICATION

DRAINAGE

This Specification includes references to British Standards however equivalent Eurocodes are

acceptable. 1.0. SCOPE

1.1. This Specification deals with the general requirements for the materials, workmanship

and testing for drainage works.

1.2. Reference to the Engineer shall mean Ridge and Contractor shall mean Main

Contractor.

2.0. GENERAL

2.1. The execution of the work shall generally be in accordance with BS EN 752 and

BS8005 and the Water Authorities Association‟s publication „Sewers for Adoption‟,

which shall be considered part of this Specification. Job specific drawn details take

precedence over this specification.

2.2. There shall be no deviation from this Specification without the prior written approval of

the Engineer.

2.3. Where a survey of existing drainage is required it shall be carried out within the

guidelines of BS 8005.

3.0. MATERIALS

3.1. Certification

3.1.1. The Contractor shall provide the Engineer with copies of the manufacturers‟

certificates verifying compliance with this Specification.

3.2. Classification

3.2.1. All materials shall be of the class specified herein or as shown otherwise on the drawings. They shall be obtained from the manufacturer or his accredited stockist and be marked with the manufacturer‟s name or mark. Flexible joints shall be used wherever possible and the components shall be those which are recommended by the manufacturer and which have received the approval of the Engineer. Pipes and fittings of the same type from different manufacturers shall not be jointed together.

3.2.2. All materials complying with British Standards shall be obtained only from

manufacturers licensed under certification mark scheme known as the “Kitemark” operated by the British Standards Institution.

3.2.3. Vitrified clay pipes, fittings and joints shall comply with BS EN 124.

3.2.4. Bricks shall comply with Class B: BS 3921.

3.2.5. Concrete shall comply with the Concrete Specification and shall be of the type

specified on the drawings.

3.2.6. Filter material for French drains shall be as specified on the drawing.

3.2.7. Granular material for pipe bedding shall be 10mm single size aggregate to BS 882

unless specified otherwise on the drawings.

3.2.8. Joint filler for movement joints in concrete pipeline construction shall be compressible

wood fibreboard bonded with bitumen or cork granule board bonded with resin or bitumen.

3.2.9. Manhole covers, road gully gratings and frames for drainage purposes shall comply

with BS EN 124.

3.2.10. Manhole steps shall comply with BS EN 13101 – plastic encapsulated „double‟ step

type and ladders hot dip galvanised mild steel to BS EN 14396 unless otherwise stated.

3.2.11. Mortar mixes for bedding pre-cast manhole sections and cover frames, mortar for

bedding bricks, cement rendering for inverts and benching and granolithic finish shall comply with the following table:

--------------------------------------------------------------------------------------------------------

Use Cement : sand ratio Specification

----------------------------------------------------------------------------------------------- ---------

Bedding pre-cast concrete BS 1199

manhole sections, cover 1 : 3 &

frames & bricks. BS 1200

Rendering of inverts BS 1199

and benchings 1 : 2 & BS 1200

Granolithic rendering 1 : 1 BS 882

(fine aggregate)

: 2

(coarse aggregate)

3.2.12. Safety chains for manholes on sewers of 600mm diameter and over shall be 10mm.

Nominal size, short link smooth welded chain to BS 4942 Pt.2 made of stainless steel.

3.2.13. Sealant for sealing joints in pre-cast concrete manholes requires the prior approval of

the Engineer.

4.0. WORKMANSHIP

4.1. Setting Out

4.1.1. The setting out of all drains shall be carried out by suitable laser beam setting out

equipment. The accuracy of which shall be demonstrated to the satisfaction of the

Engineer on demand.

4.1.2. Temporary bench marks shall be established in stable positions where they are

unlikely to be disturbed.

4.2. Excavation

4.2.1. The excavation shall be carried out generally in accordance with the Excavation and Earthworks Specification.

4.3. Inspection of Pipes Preparatory to Laying

4.3.1. Each pipe shall be carefully examined on arrival on site. Sound pipes shall be carefully stored to prevent damage; any defective pipes rejected shall be segregated, marked in a conspicuous manner and removed from the site.

4.3.2. Pipes shall not be stacked so high as to overload the bottom layers, shall not rest

directly on the ground and sockets shall not rest on other pipes in the stack. The end pipes in the bottom row shall be securely chocked to prevent collapse of the stack.

4.3.3. Where pipes are provided with factory applied jointing material, they shall be

examined when delivered and all pipes stacked in accordance with the maker‟s instructions to avoid subsequent damage to both pipes and joints.

4.3.4. Each pipe and joint shall be carefully re-examined for soundness and cleanliness

immediately before laying.

4.4. Cutting of pipes

4.4.1. Pipes and fittings may be cut provided that they are suitably held, supported and protected during the process. All ends shall be cut square to the longitudinal axis of the pipe, except where splay cuts are necessary for the works. In the case of pipes the standard lengths of which are greater than one diameter and should the length to be made up be less than one diameter, then two pipes shall be cut to satisfy this requirement. The contractor shall obtain the Engineer‟s approval of the cut lengths before they are used.

4.4.2. Where concrete pipes and fittings have been cut, any exposed reinforcement shall be cut nearly flush with the concrete face.

4.5. Pipe laying

4.5.1. General

4.5.1.1. Pipes shall be lowered into the trench with tackle suitable for the weight of the pipe. Care shall be taken that the coating, if any, is not damaged.

4.5.1.2. After laying and jointing pipes, any coating, sheathing or wrapping shall be examined

and any damage shall be repaired to the satisfaction of the Engineer.

4.5.1.3. Pipes shall be laid in straight lines to even falls from manhole to manhole, unless

shown otherwise on the drawings, and in the uphill direction. With the prior written approval of the Engineer, pipelines may be laid to slow and even curves on plan to avoid obstruction and upon completion a true record of the line shall be made by the Contractor and given to the Engineer.

4.5.2. Laying Flexible and Rigid Pipes on Granular Bed

4.5.2.1. Unless shown otherwise on the drawings, the trench shall be excavated below the invert level of the pipe to a depth which will allow a minimum thickness of 100mm of granular bedding material, below the barrel, or minimum 50 mm below socket, which shall extend to the full width of the trench.

4.5.2.2. Pipes shall be laid with the sockets upstream directly on the granular bed, which shall

be adjusted to ensure exact line and level and uniform bearing. Pipes shall rest evenly on the granular bed for the full length of their barrels and never on their sockets nor on any local hard packing such as timber, bricks or stones. Socket holes, where needed, shall be as short as practicable and shall be scraped in the granular bed deep enough to prevent the socket from bearing on the bottom. Socket holes shall be repacked after pipe laying.

4.5.2.3. Adjustments to the level of the pipes shall be made by raising or lowering the granular

bedding. The pipes shall rest evenly on the adjusted bedding through out the length of their barrels. Adjustments shall never be made by local packing.

4.5.3. Laying Rigid Pipes with Concrete Cradle or Surround.

4.5.3.1. The trench shall be excavated below the invert level of the pipe to the depth shown on the drawings. The pipes shall be laid with sockets upstream and shall be supported clear of the trench bottom by means of blocks or cradles placed under the pipe and immediately behind each socket for short small pipes, with a second block near the spigot end for long or large pipes. The nature of these supports shall be such that they will yield under load sufficiently to permit the barrel of the pipe to rest uniformly on its bed after the normal setting shrinkage of the concrete has occurred. The clearance under the barrel shall not be less than the specified thickness of the cradle or surround.

4.6. Jointing Pipes

4.6.1. Flexible joints shall be made in accordance with the manufacturer‟s instructions. The

jointing faces and sealing rings shall be clean and free from oil, grease, tar, mud or sand particles. Pipes with deeply chipped ends shall be rejected. In placing the pipes and making the joints, care shall be taken to avoid disturbance, which may occur accidentally. An expansion gap shall be left between the end of the spigot and the shoulder of the socket of the next pipe.

4.6.2. Where pipes are to be jointed with flexible joint, the Contractor shall ensure that the

pipe jointers are skilled in the necessary techniques for the work and, before work commences, the Contractor shall arrange for a representative from the pipe or joint manufacturers to instruct the operators in the correct jointing procedures.

4.6.3. Where the drawings require a pipeline to be firmly built into a wall of a manhole or any

other structure the joint between the structure and the pipe shall be watertight. In addition, the first two pipes on each run shall have flexible joints and, when the bedding is in concrete, corresponding movement joints. The first joints from the inside face of the structure shall be 600mm with the next pipe being 0.75m length for diameter up to and including 450mm and 1m for larger diameters.

4.6.4. After laying and before backfilling or placing bedding or surround concrete, all

pipelines shall be checked for line, level and gradient and shall be tested for watertightness.

4.7. Construction of Bedding and Filling for Pipework

4.7.1. General

4.7.1.1. Concrete in cradle, arch or surround to pipes shall be in accordance with the Concrete

Specification and relevant drawings.

4.7.1.2. Where the Contractor intends a concrete cradle, surround or arch to occupy less than

the full width of the trench, he shall erect vertical formwork to retain the concrete. Following this concrete construction, granular or selected material as shown on the drawings shall be placed by hand and compacted firmly by hand in 100 to 150mm layers alongside the concrete up to the top level of the concrete.

4.7.1.3. Unless shown otherwise on the drawings, movement joints shall be provided at all

flexible joints in pipelines in concrete construction, at intervals not exceeding 5m. Width of joints up to 450mm diameter pipe –18mm thick, 450 to 1200mm diameter pipe – 36mm thick, exceeding 1200mm diameter pipe – 54mm thick.

4.7.1.4. Particular care shall be taken to locate the reinforcement relative to the pipe as shown

on the drawings and to ensure that it is not displaced after fixing.

4.7.1.5. Concrete shall be placed between movement joints in one operation.

4.7.1.6. The concrete shall be protected from adverse weather and kept damp for a minimum

period of 24 hours after which backfilling shall commence.

4.8. Bedding to Pipes

4.8.1. Unless noted otherwise on the drawings, the bedding shall be Class S.

4.8.2. Class S Bedding – 360 Degrees Surround

4.8.2.1. Granular material shall be placed by hand and compacted by hand along the side and up to the centre line of the pipes so as to buttress them to the sides of the trench. The filling shall then continue to 150mm above the top of the pipe using granular material. This material shall be compacted with hand rammers in 100 to 150mm layers. Granular material shall be as specified on the drawings.

4.8.3. Class B Bedding – 180 Degrees Surround

4.8.3.1. Granular material shall be placed by hand and compacted by hand along the side and up to the centre line of the pipes so as to buttress them to the sides of the trench. Selected fill shall then be placed by hand and compacted by hand rammers in 100 to 150mm layers on either side of the pipe up to its crown and continue to 300mm above the top of the pipe. Selected fill and granular material to be as specified on the drawings.

4.9. Construction of Ground Water Drains

4.9.1. Filter Drains

4.9.1.1. Granular material as specified on the drawing shall be placed and compacted

thoroughly to a depth of 150mm upon the Terram, or other specified geotextile, lined trench formation to give a uniform bed on which the pipe shall be laid directly. Where perforated pipes are called for on the drawings they shall be laid with the perforations facing upwards. Filter material shall be placed by hand and compacted by hand alongside the pipe to the mid-diameter.

4.9.1.2. Above mid-diameter filter material shall be laid in layers not exceeding 225mm thick

up to a finished surface level.

4.9.1.3. Terram or other specified geotextile shall be lapped 300mm over the top and covered

as detailed on the drawing.

4.10. Manholes and Catchpits

4.10.1. General

4.10.1.1. In situ concrete bases, shafts and cover slabs shall be cast in concrete in accordance with the Concrete Specification.

4.10.1.2. Curved channel inverts shall have the largest possible radius.

4.10.1.3. Where the drawings require a manhole to be surrounded in concrete the whole of the space between the manhole wall and the excavation to within 1m of surface in fields and to underside of formation of roads shall be filled concrete in accordance with the Specification not less than 150mm thick.

4.10.1.4. Each cover frame shall be located with the cover in the position on one to three

courses of brickwork and shall be solidly bedded over its whole area so as to obtain an even bearing on the brickwork.

4.10.1.5. For brick or in situ concrete manholes, steps shall be built into the wall at every fourth

course or at 300mm intervals, shall be set, in vertical runs. The top step shall be 450mm below the top of the manhole cover and the lowest not more than 300mm above the benching. Pre-cast concrete manholes shall have steps cast into the sections as provided for in BS EN 1917 and BS 5911.

4.10.1.6. Safety chains shall be fixed at half pipe level on the outlet pipe of manholes on drains

and sewers of 600mm diameter and over.

4.10.1.7. Sizes of manholes shall be as indicated on the drawings.

4.10.2. Channels, Branches and Benching

4.10.2.1. The open channel in the bottom of the manhole inspection chamber shall be formed in

half-round channel pipes, tapers or junction as may be required and shall extend for the whole length of the manhole, and as illustrated on detail drawings. In the case of pre-cast concrete manholes or inspection chambers, the base incorporating the necessary channels may be pre-cast. Where there is no change of diameter the channel invert shall follow the same gradient as the incoming and outgoing pipelines, projected to the centre of the chamber.

4.10.2.2. Side branches of 150mm nominal bore shall be brought into the main channel by the

use of branch bends to standard angles and dimensions. The bends shall be bedded in cement mortar and connected to the main channel so that the discharge from the branch drain is in the direction of flow in the main channel.

4.10.2.3. Three-quarter section branch bends with a uniform projection of less than 225mm

shall not be used without the written permission of the Engineer.

4.10.2.4. Where manhole fittings, such as those described above, are not made in the

appropriate sizes, the channels shall be formed in concrete, in accordance with the Concrete Specification, and, while still “green” finished with granolithic rendering.

4.10.2.5. The benching shall rise vertically from the top edge of the channel pipe to a height not

less than that of the soffit of the outlet and be sloped upwards thence to meet the wall of the manhole at a gradient of about 1 in 12.

4.10.2.6. In the case of branch drains the benching shall be so shaped round the channel

branches as to guide the flow in the desired direction. 4.10.2.7. Where practicable, the soffits of the main pipes entering and leaving the manhole shall

conform to a general level of inclination. The inverts of branch drains entering a manhole shall be above the horizontal diameter of the main channel unless shown otherwise on the drawings.

4.10.2.8. Except where a granolithic finish is called for on the drawings, the concrete shall be

floated to a smooth hard surface with a coat 1 : 2 cement mortar, laid monolithic with the benching. The top of the vertical part of the benching shall be rounded off to a radius of about 25mm.

4.10.3. Brick Manholes

4.10.3.1. Bricks shall be laid in English Bond. Beds and vertical joints shall be completely filled with mortar as the bricks are laid and joints shall be flush cut as the work proceeds.

4.10.3.2. Pipes where build into walls shall have 2 half brick ring arches turned over to the full

thickness of the brickwork or precast concrete lintels where illustrated on drawings.

4.10.4. Pre-cast Concrete Manholes

4.10.4.1. Bases shall be pre-cast units or cast in situ as shown on the drawings to form the foundation for the lowest chamber section.

4.10.4.2. The sections shall be bedded in mortar and flush pointed internally, the bed of mortar

under the lowest section shall be at least 10mm thick. Step irons shall not be used for hoisting or lowering components.

4.10.4.3. When a pre-cast concrete manhole is shown on the drawings to be surrounded in

concrete, horizontal construction joints shall not be formed in the surround within 150mm of a joint between sections. This concrete shall support the cover slab with a space of 20mm between it and the top of the highest section.

4.11. Connections

4.11.1. The Contractor shall obtain the written approval of the appropriate authority before breaking into any existing manholes, drains or sewers or diverting existing flows.

4.11.2. The positions and invert level of all existing manholes, drains and sewers, to which

connections are to be made, shall be checked by the Contractor before pipe laying commences, including those which involve advance trial pitting, and any discrepancies shall be notified to the Engineer immediately.

4.11.3. Connections to existing sewers and drains shall not be formed in such a way as to

constitute a projection into a sewer, or to cause any diminution in its effective size, or to create uneven support for either the main sewer or drain or the branch. The Contractor shall submit to the Engineer for approval the method proposed for making the connection prior to the work commencing on site.

4.11.4. Where an incoming connection either direct or as a backdrop enters an existing

manhole, the benching shall be cut away, built up and made good in order to form a channel at least equal in depth to the diameter of the incoming connection, and so shaped as to direct the flow down the sewer. The Contractor shall keep the existing drain or sewer open to flow and free from debris at all times during the progress of the work.

4.11.5. When completed all work shall be watertight.

4.12. Sealing, Marking and Cleaning

4.12.1. When a pipeline is completed or when construction is delayed, the open ends of pipes shall be stoppered or sealed off until the pipeline is required to operate or work recommences.

4.12.2. At each point where a pipeline is temporarily terminated a marker shall be attached to

the end of the pipeline and fixed at ground level.

4.12.3. The interior of all pipelines shall be clean when commissioned.

4.13. Backfilling and Reinstatement

4.13.1. Backfilling and reinstatement shall comply with the requirements of BS8005, details on drawings, this Specification and the Earthworks Specification.

4.13.2. Mechanical rammers, rollers and the like shall not be used to consolidate the fill until

there is 750mm of fill above the top of the pipe, unless directed otherwise by the Engineer.

5.0. TESTING

5.1. Testing Drainage Runs

5.1.1. Tests for line, level and freedom from obstruction shall be applied to all pipelines prior

to the placing of the backfill and again when backfilling and the reinstatement of the

surface has been completed. For small bore pipes the tests shall be carried out by

means of a mirror at one end of the line and a lamp at the other.

5.1.2. When instructed by the Engineer and where the crown of the pipe at the high part of

the length under test is more than 1.2m below the water table, an infiltration test shall

be employed. Visual inspection at manholes or inspection chambers will then reveal

excessive flow. The acceptable rate of infiltration will depend on the judgement of the

Engineer.

5.1.3. All pipelines other than porous and perforated pipes shall be air tested in accordance

with BS 8005 after pipe laying and jointing has been completed and before any

backfilling takes place. This is to be followed by further testing on completion of

backfilling. Wherever possible, testing shall be carried out from manhole to manhole.

Short branches connect to the main pipeline shall be tested as one system separately.

With the prior written approval of the Engineer, pipelines may be tested when

backfilling and the reinstatement of surfaces have been completed. Failure to pass the

air test shall not preclude acceptance of the pipeline is a successful water test can

subsequently be carried out.

Air testing: shall include air pumped in by a suitable means until a pressure of 110mm

head of water is indicated in a U-tube connected to the system and held for

approximately 5 minutes prior to testing. The pipe shall be accepted if it then holds an

initial 100mm pressure with a maximum loss of head on the U-tube of 25mm in a

period of 7 minutes.

Water testing: For pipes up to 300mm diameter the system is to be filled with water up to

a depth of 5m above the lowest invert in the test section subject to a minimum depth

of 1m measured at the highest invert of the test section. The test section is to be left

for a minimum period of 1 hour to allow for for absorption. The test pressure is then to

be maintained for a period of 30 minutes, by topping up the water level as necessary

so this is within the required level throughout the test. The losses per square metre of

surface area should not exceed 0.15 litres for test lengths of only pipelines or 0.20

litres for test lengths including pipeline and manholes, or 0.40 litres for tests with only

manholes and inspection chambers alone (ie no pipelines). Notwithstanding the

satisfactory completion of the above test, if there is any discernible leakage of water

from any pipe or joint, the pipe shall be replaced and the joint remade, as appropriate,

and the test repeated until the leakage is stopped.

5.1.4. The Contractor shall give adequate notice to the Engineer of the times and places at

which all tests are to be held.

5.1.5. The work shall not be considered complete until a successful test has been

applied.

5.2. Testing Filter Drains

The Contractor shall notify the Engineer when each pipeline and each catchpit is

complete, so that he can examine them before backfilling commences. Should the

Engineer require any further tests, he will instruct the Contractor accordingly.

5.3. Testing Manholes

5.3.1. After sealing all pipe openings, all manholes shall be filled with water up to underside of the cover, or to a maximum of 9m total head in the system, which ever is the lesser, and left for a minimum period of 24 hours. At the end of this period, the manhole shall maintain the test water level for a minimum period of 0.5 hour without the water level falling more than 10mm per metre depth.

5.3.2. Before sealing the outgoing pipe the Contractor shall ensure that the seal may be

easily removed upon completion of the Test. Complete filling of the outgoing pipe to the next manhole will be permitted provided that the pipeline has been previously tested and approved and that the head does not exceed 10 metres.

6.0. RECORDS AND TOLERANCES

6.1. Upon completion of each test a copy of the complete records shall be given to the Engineer for his retention.

6.2. The inverts of pipes at manholes shall be within +/- 10mm of the designed inverts with

the overriding requirement that relevant pipe gradients shall be within 2.5% of their design value stated on the drawings.

6.3. Immediately upon completion of a length of drain run between manholes, the

Contractor shall provide the Engineer with the following information: (i) Invert at both end of pipe, (ii) Length of pipe, (iii) Gradient.

6.4. If a pipe is so discovered to be outside the tolerance in 6.2. the Contractor shall

submit to the Engineer, for approval, his method of remedying the error and shall, upon approve, carry out such work without further drain-laying to or from the erroneous section of the work.

7.0 CCTV Surveys

On completion of the drainage works and following backfilling and surface

reinstatement, where appropriate, the Contractor shall thoroughly clean all

pipelines by high pressure water jetting. This is to be followed by a CCTV

survey, supplied by the Contractor, of all drains and sewers constructed

during the Contract, unless other pipelines are also included as illustrated on

the drawings.

The format of the survey is to be in accordance with the local Water

Authority / Company specification and copies of the completed survey video

or DVD and supporting written report are to be supplied to the Engineer.

CCTV surveys of any drains laid beneath building floors shall be carried out,

after water jetting, prior to the construction of floor slabs, in addition to the

final version as above.

A p p e n d i x

Document 1 Pipe Run Inspection Schedule Document 2 Manhole Inspection Schedule

Pipe Run Inspection Schedule

To be completed by the Contractor for all pipe runs (foul and storm) and submitted to the Engineer prior to CCTV survey or backfilling whichever is the earlier.

Design As Built

Upstream End (Manhole, rodding eye number etc.) .. ..

Downstream End (Manhole, rodding eye number etc.) .. ..

Upstream End Co-ordinates .. .. .. ..

Downstream End Co-ordinates .. .. .. ..

Pipe length .. .. .. ..

Material .. .. .. ..

Pipe Diameter .. .. .. ..

Pipe Invert upstream .. .. ..

Pipe Invert downstream .. .. ..

Pipe Gradient .. .. ..

Air Test Date

pass

fail

Line Test (laser) Date

pass

fail

Freedom from Obstruction Test Date

pass

fail

Contractors proposal for remedial work should any item not comply with Specification and Design requirements.

Manhole Inspection Schedule

To be completed by the Contractor for all manholes - Section A when constructed - Section B when completed and issued to the Engineer.

Design As Built

Section A Manhole number .. .. .. .. Material .. .. .. .. Concrete surround thickness

Incoming Pipes 1. Invert on pipe .. .. .. ..

Diameter .. .. .. .. Material .. .. .. ..

2. Invert on pipe .. .. .. .. Diameter .. .. .. ..






Outgoing Pipe Invert on pipe .. .. .. .. Diameter .. .. .. .. Material .. .. .. ..

Section B Benching Date completed .. .. .. ..

Cover Date fully fitted .. .. .. ..

Water Test Date carried out .. .. .. ..

pass

fail

Contractors proposal for remedial work should any item not comply with Specification and Design requirements.

SPECIFICATION

EARTHWORKS This Specification includes references to British Standards however equivalent Eurocodes are


1.1. This Specification deals with the general requirements for materials and workmanship

for excavation and filling and hard landscaping.

1.2. Reference to the Engineer shall mean Ridge and the Contractor shall mean Main

Contractor.

2.0. GENERAL

2.1. The execution of the work shall be in accordance with this Specification and Series 600 of Department of Transport Specification for Highway Works, which shall form part of this Specification.

2.2. There shall be no deviation from this Specification without the prior written authority of

the Engineer.

3.0. MATERIAL

3.1. Unsuitable material is that material which is unsuitable for retention in formation and/or for re-use after excavation and which is classified as follows: (a) From swamps, marshes or bogs, (b) Peat, stumps, perishable materials, (c) Susceptible to spontaneous combustion, (d) In a frozen condition, (e) Clay of liquid limit exceeding 90 and/or plasticity index exceeding 65, (f) Otherwise suitable material which becomes unsuitable in terms of moisture

content because of lack of suitable protection, unsatisfactory conditions at time of handling or unsuitable methods of handling.

3.2. Suitable material is that material suitable for retention in formation and/ or for re-use

after excavation classified in accordance with Clause 601 of D.O.T. Specification.

3.3. Top soil for re-use shall be from the top humus bearing horizons of the soil, free from

chemical or other pollutants, pests, unwanted weeds, roots and rubbish.

3.4. Selected material in the immediate vicinity of pipes in trench shall be as specified on the drawings.

3.5. Selected material above pipe surround material shall be selected from excavated

material and shall be free from particles over 75mm and lumps of cohesive material over 150mm.

3.6. Any fill material used within 500mm of concrete structures or cement bound materials

shall have a soluble sulphate content not exceeding 2.5g per litre when tested in accordance with Test 10 of BS 1377 unless special precautions to the approval of the Engineer are taken to protect the concrete or cement bound materials.

3.7. Granular fill shall be of size 20mm down crushed rock or gravel.

3.8. Imported granular material for bedding and filling around pipelines shall comply with

Table 1 of BS 882 and unless otherwise shown on the drawings shall be 10mm single size.

3.9. Hardcore

3.9.1. Specific reference should be made to the drawings and specification for roads for details of sub-base materials to buildings, roads and paved areas.

3.9.2. Hardcore not otherwise specified shall be good clean hard brick, concrete, hard stone,

coarse gravel, sound slag or other approved inert material free from dust and foreign matter, the maximum size of which shall not exceed two-thirds of the thickness of the compacted layer and which shall be graded so that when compacted the layer is uniformly dense. Screenings will also be required to fill surface voids.

3.10. Solid rock shall mean rock found in ledges or masses in its original position which

would have to be loosened either by blasting or by pneumatic tools, or if excavated by hand, by wedges and sledge hammers. All solid boulders or detached pieces or rock exceeding 0.10m

3 in size in trenches or exceeding 0.20m

3 in general excavation shall

be regarded as solid rock.

3.11. Rock fill shall consist of hard durable inert material of suitable size for deposition and

compaction.

3.12. Testing

3.12.1. The Contractor shall carry out all necessary materials sampling and testing to confirm that materials and workmanship are in accordance with the specification to the satisfaction of the Engineer.

3.12.2. The Contractor shall provide details of his testing laboratory for the Engineer’s

approval.

3.12.3. The Contractor shall submit his proposals for testing materials for the Engineer’s

agreement.

4.0. WORKMANSHIP

4.1. Construction Materials

4.1.1. Concrete shall comply with the Concrete Specification.

4.1.2. Waterproof membranes for covering sub-drains shall be polythene sheets not less

than 0.8m thick or other material approved by the Engineer.

4.1.3. Pervious membranes to be used on clay sub-grades to reduce pumping of the clay or

silt into the base shall be 100 per cent polypropylene non-woven fabric, weighing not less than 135g/m

2. Overlapping of membrane joints shall be in accordance with the

manufacturer’s instructions.

4.2. Tolerance Limits

The tolerance limits for the permanent finished earthwork shall be as follows: 4.2.1. Horizontal dimensions shall be within +/- 150mm of the dimensions shown on the

drawings.

4.2.2. For slopes to embankments or cuttings the horizontal deviation between the top and

the bottom of the slope shall be within +/- 5 per cent of the horizontal component of the slope shown on or calculated from the drawings.

4.2.3. Formation levels shall be within zero and – 30mm of the levels shown on the

drawings.

4.2.4. Other earthwork levels shall be within zero and – 100mm of the levels shown on the

drawings.

4.3. Settlement and Heave Allowance

In the setting out and construction of excavations and filled areas the Contractor shall

allow for settlement and heave whether caused by consolidation of fill, settlement of

foundations, heave in excavations or change in volume of materials after excavation.

4.4. Borrow Areas

Where, for any reason, it becomes necessary to form borrow areas on the site, these

shall be located and the work executed to the approval of the Engineer.

4.5. Stockpiles, Spoil and Topsoil and Heaps

The Contractor shall submit proposals for the stockpiles and for storage areas for soil,

turf and topsoil and shall obtain the approval of the Engineer.

4.6. Earthworks to be kept free of Water

4.6.1. The Contractor shall arrange for the rapid disposal of watershed on to all earthworks or completed formations of all types during construction or which enters the earthworks from any sources. The Contractor shall arrange for suitable temporary discharge points he requires and obtain any necessary approvals from Water or other affected Authority for temporary connections and discharge consents. Adequate means for trapping silt, oil and other deleterious matter shall be provided on temporary systems discharging into permanent drainage systems.

4.6.2. The Contractor shall provide where necessary temporary water courses, ditches,

drains, pumping or other means of maintaining the earthworks free from water. Such provisions shall include carrying out the work of forming the cuttings and embankments in such a manner that their surfaces have at all times a sufficient minimum crossfall and, where practicable, a sufficient longitudinal gradient to enable them to shed water and prevent ponding.

4.6.3. In pumping out excavations and in any other operation which could vary the water

tables or affect in any way the permanent works, the Contractor shall pay due regard to the stability of all structures and shall submit his proposals to the Engineer before commencing such operations. Pumping sumps shall be kept clear of the construction limits of permanent works.

4.7. Adverse Conditions

4.7.1. The Contractor shall not carry out any excavation or placing of fill materials when conditions are such that the quality of the work, or of adjacent works, would be adversely affected. After any operation has been stopped, owing to adverse conditions, it shall not be re-started without the approval of the Engineer.

4.7.2. The Contractor’s attention is particularly drawn to the fact that certain fill types may be

expected to be more susceptible to adverse weather conditions than other types and he shall so plan his operation as to take full advantage of changing climatic conditions and minimise loss of production owing to adverse weather.

The Contractor shall seek the Engineer’s approval to any changes in his method of

working that are necessary, to ensure full compliance with this requirement before the

changes are implemented.

4.8. Land Slips

4.8.1. The Contractor shall notify the Engineer immediately of any land slips and shall then deal with these without delay.

4.8.2. If any slip of fall disturbs or weakens any foundations or support which the work would

otherwise have had or causes a space to exist outside the new work, the Contractor shall, at his own expense, fill up the space or execute such additional work as the Engineer may direct.

4.9. Original Ground Levels

Should the Contractor dispute the original ground levels shown on the drawings, he

shall agree these with the Engineer before commencing excavation or filling.

4.10. Surplus Material and Topsoil

4.10.1. All surplus material and topsoil shall be used or disposed of in accordance with the instructions on the drawings.

4.11. Excavations for Cuttings, Structures, Foundations, Pits and Service Trenches

4.11.1. Unless specified or instructed otherwise, excavations may have battered sides, but this does not entitle the Contractor to increase the size of the site.

4.11.2. Any old foundations, tree roots or buried rubbish or obstructions encountered during the course of excavation shall be taken out and burned or removed from site.

4.11.3. Where excavation produces a combination of suitable and unsuitable materials, the Contractor shall carry out the excavation in such a manner that the suitable materials are excavated separately for use in the works without contamination by the unsuitable materials, which shall be removed off site. Where the natural sub-soil drainage depends on the relative positions of permeable and impermeable strata these materials shall be excavated and stored separately.

4.11.4. No excavated material shall be removed off the site if the Engineer considers that it is

unsuitable only by reason of being frozen or having a variable moisture content which conditions will be improved when weather conditions change. Materials used for haul roads shall not be re-used without the permission of the Engineer.

4.11.5. The faces of excavations shall be adequately supported or battered against any form

of slip, collapse, fall or heave. They shall be kept free from noxious gases, whether generated in strata or otherwise. The Contractor shall satisfy himself that each excavation is safe before allowing men to enter.

4.11.6. On completion of the excavation the formation shall be neatly finished leaving no

extraneous material. It shall be compacted by 4 passes of a smooth wheeled roller having a mass of 5400kg (or by plant approved by the Engineer). It shall be immediately covered with the permanent works, or sealed to the approval of the Engineer.

4.11.7. Where the excavation must be carried out for programme reasons, but the bottom

cannot immediately be completed and sealed, the excavation may be taken down to 150mm above the proper depth required and the removal of this last 150mm delayed until proper completion can be done.

4.11.8. The Contractor shall provide the Engineer with copies of his records of the strata

through which he excavates.

4.11.9. Should an unforeseen service be encountered the Engineer shall be notified and no

action taken pending his instructions. When instructed by the Engineer disused drains shall be traced and sealed with concrete.

4.11.10. The natural moisture content of the ground below the formation shall be preserved as

far as is practicable.

4.11.11. The permanent work shall be placed on the formation as soon as possible after it has

been inspected and approved by the Engineer. The Contractor shall give adequate notice to enable this to be done. Should any part of the formation subsequently be damaged or become wetter or drier than its natural state, it shall be excavated further as instructed by the Engineer, a new formation prepared and the excavation filled as specified.

4.11.12. When constructing structures and laying adjacent services the construction requiring

the deepest excavation shall be executed first. When this is impracticable the Contractor shall obtain the approval of the Engineer to his proposals for maintaining undisturbed the ground supporting the higher construction while constructing the filling over and/or around the lower one.

4.12. Excavation Below Formation Level and Filled Areas

4.12.1. Excavation by the Contractor to a greater depth than is indicated on the drawings shall be made good with concrete in accordance with the Concrete Specification or other approved material deposited and compacted all as specified.

4.12.2. Soft or unsound spots in the formation or under areas to be filled shall be excavated

as instructed by the Engineer. The resultant excavation shall be backfilled with concrete or other approved material deposited and compacted as specified for the forming of filled areas.

4.13 Excavation in Trenches for Services (Particular Requirements)

4.13.1. Trenches for drains and sewers shall be excavated to an even gradient between manholes and to the depth required by the drawings. Trenches for other services shall be excavated to give the specified cover. Allowance shall be made for bedding, when specified.

4.13.2. Unless shown otherwise on the drawings, trenches for pipelines and conduits, other

than those forming a French drain, shall not exceed the width given in the following table, from the formation level to 300mm. above the crown of the pipe. Above a level 300mm above the crown of the pipe the trench sides may be battered. If the specified width is exceeded the Contractor shall notify the Engineer immediately to enable him to check the design.

--------------------------------------------------------------------------------------------------------

Maximum Trench Width

Internal Diameter of pipes Non-flexible pipes Flexible pipes

--------------------------------------------------------------------------------------------------------

Not exceeding 300mm nominal 700mm ] Outside

------------------------------------------------------------------------------------

Over 300mm and less than Outside diameter ] diameter

840mm nominal plus 400mm ]

------------------------------------------------------------------------------------ plus

840mm and over Outside diameter ]

plus 600mm ] 300mm

--------------------------------------------------------------------------------------------------------

Note : Where trench supports are necessary all widths may be increased by 150mm.

4.13.3. Whenever land drains are encountered their positions, invert levels and materials shall

be recorded to facilitate their reinstatement. Records shall be submitted to the Engineer.

4.13.4. Unless shown otherwise on the drawings, pipes and conduits shall not be laid in fill

unless the fill has been compacted completely along the line of the pipe before the trench is excavated. Where pipes or conduits are to be laid in undisturbed ground with less cover than 500mm and over which fill is to be placed later, sufficient fill shall first be placed and compacted along the lines of the pipes/conduits to provide at least 500mm cover before the trench is excavated.

4.13.5. Where the trench formation for pipelines and conduits is in fine grained soils such as

soft clays, silts or find sand it shall be blinded with a 75mm layer of granular material immediately after the formation has been approved.

4.13.6. Rock projections, boulders or other hard spots in trenches for pipelines and conduits

shall be removed to a depth of not less than 100mm below formation level or as directed by the Engineer and a new formation prepared and the excavation filled as specified.

4.14. Filling and Compaction

4.14.1. All filling materials shall be deposited and compacted in accordance with D.O.T. Specification according to their classification.

4.14.2. If there is an adverse “cut-fill” balance of suitable materials from the excavations the

deficiency shall be made good by suitable imported material. The Contractor may propose a source of such material for the Engineer’s approval.

4.14.3. Where materials of different characteristics are readily available those of relatively

high bearing capacity shall be placed in the topmost 600mm below formation level.

4.14.4. All filing material used in earthworks shall be compacted in accordance with the

D.O.T. Specification and the Contractor shall submit to the Engineer for approval his proposals for the compaction of each main type of material to be used in the filled areas and embankments, the types of plant to be used, the number of passes and the loose depth of layer. The Contractor shall carry out compaction trials for the earthworks, supplemented by any necessary laboratory investigations, using an approved procedure. The Contractor shall satisfy the Engineer that all the specified requirements regarding compaction can be achieved. Compaction trials with the materials likely to be encountered shall be completed with the corresponding materials, before the works will be allowed to commence.

4.14.5. Work on the compaction of both cohesive and non-cohesive material shall proceed as

soon as practicable after excavation.

4.14.6. If the Contractor allows the moisture content of suitable materials to change after

excavation to a value unsuitable for compaction, he shall raise or lower the moisture content as required.

Unsuitable material shall be run to spoil heaps and replaced with an equal quantity of

material suitable for compaction.

4.14.7. Filling of foundation pits and trenches shall be carried out with suitable plant and shall

be laid in layers not exceeding 100mm for granular materials and 200mm for other suitable selected materials. Nay trench supports shall be removed carefully in stages. Allowance shall be made for settlement and consolidation and any deficiency shall be made good.

4.14.8. Areas to be filled shall be clear of rubbish, scrap material and standing water when fill

material is placed.

4.14.9. Excavation shall not be filled in until the services have been tested and approved by

the Engineer, except where pipes are top be protected by a concrete cradle, or laid on a bed of granular material; joint holes shall be filled in with material in advance of general filling. Filling around pipes and between sides of trench faces and for 300mm over the pipes shall be find material free from stones, filled by hand and compacted with hand rammers.

4.14.10. No mechanical rammer shall be used within 750mm of the top of the pipe.

4.14.11. Materials shall not be dropped from a height exceeding 1.5m when filling the one

metre depth immediately over a pipe.

4.14.12. Trenches to foundations shall be a suitable distance from the foundation to avoid

interaction in accordance with the drawings. In some circumstances concrete encasement may be required, as indicated on the drawings.

SPECIFICATION

STRUCTURAL STEELWORK


acceptable.

1.0. SCOPE

1.1. This specification deals with the materials, design fabrication and erection of structural

steelwork.

1.2. Reference to Engineer shall mean Ridge and Contractor shall mean Main Contractor or

Steelwork Contractor as befits the case.

2.0. GENERAL

2.1. The execution of the work indicating such design, detailing, fabrication and erection as may be

required shall be performed in accordance with BS 5950 and the National Structural Steelwork Specification for building construction (NSSS) together with the standards and specifications mentioned therein except as specifically varied herein or by the Engineer.

2.2. There shall be no deviation from this specification without the prior authority of the Engineer.

3.0. MATERIALS

3.1. The Contractor shall provide the Engineer with copies of manufacturer’s test certificates

verifying the materials’ compliance with the Specification. Such certificates shall apply to structural steel, bolts and associated material and electrodes if requested.

3.2. The Engineer may elect samples of steel for testing the standard for acceptance of the results

of which shall be those laid down in the appropriate British Standard.

3.3. Classification

3.3.1. All steel plates and sections shall comply with BS EN10025. Except where noted otherwise, the particular grade of steel used shall be as follows:

Sections, Bars, Flats and Plates: As tabulated below Hollow Sections (up to 16 mm thick):

S275JO Base slabs : S275 Unless noted otherwise on the drawings.

___________________________________________________________________________

(1) Sections, Flats Plates (Except

Thickness & Bars Base Slabs)

(mm) Grade S275 Grade S275

up to 20 S275 S275

21 – 25 S275 S275

26 – 30 S275JR S275JR

31 – 35 S275JO S275JO

36 – 40 S275JO S275JO

41 – 50 S275JO S275JO

3.3.2. All electrodes shall be in accordance with NSSS and shall have a yield stress and tensile

strength not less than those specified for the grade of steel being welded.

3.3.3. All nuts and bolts and washers shall be in accordance with the NSSS.

3.4. Substitution

If it is found necessary to substitute alternative sections for any of the steel sections specified

the written approval of the Engineer shall be obtained prior to fabrication and appropriate

fabrication drawings shall be submitted for approval.

4.0. DESIGN/DETAILS

4.1. General

4.1.1. All drawings shall be in accordance with the NSSS.

4.1.2. No fabrication shall commence until drawings for the relevant items are approved.

4.1.3. The Contractor shall prepare fabrication drawings and submit two copies in good time to the

Engineer for approval allowing reasonable time for the approval process.

4.1.4. The Contractors shall prepare workshop drawings incorporating sufficient information for the

proper fabrication of the steelwork together with marking drawings for erection purposes and all drawings necessary (including holding down bolts) to suit the steelwork.

4.1.5. The Engineer will verify the correct interpretation of his requirements, but will not verify the

dimensions or accuracy of details. Approval of drawings is given only on this basis.

4.1.6. The Contractor shall be entirely responsible for drawings including their accuracy (relative to

the Engineer’s drawings) the correctness of detail and the proper design of connection and

joints and shall be responsible for any additional work which may be required as a result of defects in his drawings regardless of any approval given by the Engineer.

4.2. Contractors Calculations

Unless otherwise specified herein, where the Contractor is responsible for the design of any

part of the works, he shall as soon as possible after receiving instructions to proceed, send to

the Engineer one copy of the relevant calculations. On receipt of the Engineer’s approval he

shall send a further copy of his calculations to the Engineer for the purpose of obtaining

approval under the Building Regulations. The Engineer’s approval and/or Building Regulation

approval shall not absolve the Contractor from compliance with the requirements of the current

relevant Codes of Practice and/or the Bylaws appropriate to the location of the works.

4.3. Connections

4.3.1. The Contractor shall be responsible for the structural design and details of all connections between adjoining members and shall be designed and detailed in accordance with BS 5950 and the NSSS.

4.3.2. In general all shop connections shall be welded. All welds shall be 6 mm fillet, full profile

unless noted otherwise on drawings.

4.3.3. In cleated end connections the clears shall project 2 mm (nominal) beyond the end of the

section unless full bearing is required when the end shall be machined.

4.3.4. Load carrying connections shall be designed for a minimum ultimate load of 75 kN if welded,

or if bolted shall have a minimum of 2 No. M20 dia. Grade 8-8 bolts unless noted otherwise on the drawings.

4.3.5. High strength grip bolts shall only be used when specified on the Engineer’s drawings or when

previously agreed by the Engineer.

4.3.6. Ordinary bolts in clearance holes will normally be acceptable for connection of such members

as wind bracings, sheeting rails and purlins and for beam end cleats.

4.4. Camber

4.4.1. When members are to be cambered, the amount will be specified on the drawings and the means of achieving the correct amount of camber shall be agreed with the Engineer and shown on the shop drawings.

5.0. FABRICATION

5.1. All fabrication including bolting, welding, cutting, holing and marking shall be in accordance

with BS 5290 and the NSSS.

5.2. All measurement shall be made by a steel tape related to a standard tape which has been certified to be correct a 20 degrees C. The tape and the steel to be measured shall be at the same temperature and proper precautions shall be taken to tension the tape correctly.

5.3. The ends of fitted stiffeners shall be accurately sawn or sheared and ground to fit tightly

between the flanges or parts to be stiffened.

5.4. Welders shall be suitably qualified and if required evidence shall be provided of their having

satisfactorily completed the appropriate tests. Such evidence shall be approved prior to the commencement of fabrication.

5.5. All plates, bars and sections shall be flattened and straightened and made free from twist

before any other work is done on them. The method adopted for this work shall be such as not to damage or mark the material.

5.6. Areas which become inaccessible after fabrication or assembly, such as the inside of

structural hollow sections and other box sections, shall be sealed off from the outside atmosphere by continuous welds, unless specified otherwise. Where the steelwork is to be galvanised, hollow sections shall not be sealed unless specified otherwise, and any sealing shall be sufficiently strong to prevent explosions due to expansion of the trapped air during galvanising.

5.1. Inspection

5.1.1. Every facility shall be given to the Engineer or his representative to visit the Contractor’s work

and to inspect the steelwork during all stages of the preparation and fabrication of the

steelwork and during the trial assemblies. A fabrication programme is to be submitted to the

Engineers to enable such visits to be properly co-ordinated.

5.1.2. The Engineer, will, when he considers it necessary, require tests to be made on welds by

radiographic or other means and, when flaws in the weld are found, will determine for each particular case what imperfections will require cutting out and re-welding. He may also require ultrasonic inspection of plate for laminations and where material is found to be laminated, it will be rejected unless he decides that such laminations will not be harmful.

5.1.3. The Engineer may require tests to be carried out on any item of Works and work which does

not comply with the requirements of this Specification, shall be corrected.

5.1.4. Inspection by the Engineer or his representative shall not relieve the Contractor of his

responsibility to perform his own quality control operations to ensure that all work meets the specification nor of his responsibility to rectify all defects including any which appear or are found subsequently.

6.0. ERECTION

6.1. All erection including making connection, tolerances, and site welding shall be in accordance

with NSSS except that the maximum tolerances for line and level of the steelwork framework

shall be +/- 5 mm. The steelwork shall not be out of plumb more than 5 mm on each 15 m

section of height and not more than 10 mm over the total height of the structure when the

structure exceeds 30 m in height.

6.2. On metal sprayed or galvanised steelwork ordinary bolted connections shall be made using

sheradised or zinc or cadmium plated bolts, nuts and washers except where the connection is to black steelwork.

6.3. Correcting hole alignments:

Drifts of a larger diameter than the hole being drifted shall not be used. Any misalignment of

the holes or the members shall be reported to the Engineer who will either permit the hole to

be reamed or reject the faulty member.

6.4. Plant and Equipment

6.4.1. The Contractor shall supply adequate plant, tools, service bolts, drifts, bolt tightening devices

and other equipment to ensure that the steelwork is erected in accordance with the programme.

6.4.2. All plant and equipment shall be of adequate capacity and shall be maintained in good working

order. Reasonable spares shall be provided to ensure continuity of working.

6.4.3. The Contractor is to provide all temporary bracing ties, guys, anchor blocks and any other

thing necessary to ensure safety of the structures during erection.

6.5. Setting Out

6.5.1. The Contractor shall be responsible for the correct positioning of the structure in relation to the

information provided.

6.5.2. On sites where the position of the structure is dependent upon that of adjacent existing

structures or part structures, the Contractor shall be responsible for providing an accurate survey of the buildings including all necessary angles and dimensions relevant to base lines. This information shall be provided in sufficient time to allow setting out dimensions arising out of such a survey to be established and agreed in sufficient time to comply with the programme for the work and for suppliers dependent upon such information to meet their commitments including delivery dates.

6.5.3. Immediately the foundations are available the Contractor shall satisfy himself that the

foundations have been correctly formed and that the holding down bolts have been accurately set and have the full amount of play shown on the drawings and shall inform the Engineer accordingly.

6.6. Lining and Levelling

6.6.1. The permanent welding or bolting up of connections shall not be carried out until sufficient

proportion of the structure has been erected and temporarily connected up to ensure that there will be no straining of members during the erection and lining up of the remainder of the structure.

6.6.2. Adequate temporary bracing shall be provided and left in position until such time as the building is sufficiently far advanced for such bracing to be no longer required.

6.6.3. Packs for levelling up stanchions shall be shown on the shop drawings and the number of

packs provided shall be 25% in excess of the theoretical requirement.

Packs shall not be larger than is necessary for their purpose, they shall be sawn and not

sheared or flame cut. Packs shall not protrude unduly from the stanchion base, they shall be

grouted in and the grout shall totally enclose them.

6.7. Grouting up of Structures

6.7.1. The Contractor is to be entirely responsible for the correct line level and plumb of the building

and the grout shall be in accordance with BS 5950 part 2.

6.7.2. The Engineer shall be informed, in good time, when stanchions or other members have been

lined, levelled and plumbed ready for grouting so that he may have the opportunity of checking the same prior to grouting.

6.7.3. All steelwork below ground level (or ground floor slab level, which ever is higher) shall be

encased in a minimum of 100 mm concrete (min. C30) unless specifically indicated otherwise on the drawings.

7.0. HOLDING DOWN BOLT ASSEMBILES

7.1. General

For the purpose of this Specification, the length of the holding down bolt shall be taken as the

overall length, excluding the head (or clear of the bottom nut in case of a fabricated bolt), i.e.

the sum of the embedded length, the projecting length and thickness of the anchor plate.

7.2. Manufactured Bolts

7.2.1. Bolts obtained from bolt manufacturers shall comply with the requirements of BS 4190 with regard to threads and tolerances. The material manufacture and mechanical properties shall comply with the requirements of BS 3692 or BS 4190 as appropriate.

7.2.2. Nuts shall comply with the requirements of BS 3692 or BS 4190 as appropriate and shall be of

at least the recommended grade of the bolts. Nuts shall be of normal standard thickness; thin nuts shall only be used as locknuts.

7.2.3. Unless specified otherwise, bolts shall be of strength grade 8.8 with nuts of a commensurate

grade.

7.3. Fabricated Bolts

7.3.1. Where bolts are fabricated from plain round bar the threads shall be IOS metric, coarse pitch series, free fit as specified in BS 3643. Both ends shall be threaded and the nut at the bottom end shall be welded in place to prevent it from turning. The diameter used shall be as given in Table 1 of BS 6722.

7.3.2. The weight of the bar shall be within +/- 2.5% of the weight appropriate to the true cross-

sectional area. The bolt shall be straight within a tolerance of 2 mm per metre length of the bolt, with a minimum tolerance of 2 mm. The overall length shall be accurate with a tolerance of +/- 3 mm the bottom nut being so positioned that the length (see 7.1.) shall be within a tolerance of minus zero and plus 5 mm. The threaded length shall be accurate within a tolerance of minus zero and plus 20 mm.

7.3.3. Nuts shall comply with the requirements of BS 3692 or BS 4190 as appropriate and shall be of

a strength grade such that the specified proof load stress of the nut is not less than the specified minimum ultimate tensile strength of the bolt material, except that the nuts of strength grade 4 may be used with bolts of grade S275 steel to BS EN10025. Nuts shall be of normal standard thickness; thin nuts shall only be used as locknuts.

7.3.4. Unless specified otherwise, bolts shall be of grade S275 steel to BS EN10025.

7.4. Ancillary Items

7.4.1 Anchor Plates

Unless specified otherwise anchor plates shall be fabricated from grade S275 steel to BS

EN10025. Anchor plates shall be accurate in plan size within a tolerance of minus zero and

plus 10 mm; the thickness of plate shall be within normal rolling margins as specified in BS

EN10025. Anchor plates shall be sufficiently flat and free from wrapping to prevent grout from

entering at the bottom of the sleeve (if used). The positions of snugs welded to the underside

of anchor plates shall be accurate within a tolerance of +/- 1.0 mm.

7.4.2. Sleeves

Bolt sleeves shall be made from mild steel sheet, expanded metal or polystyrene and shall be

allow the passage of cement grout into the tube. The length of the sleeve shall be accurate

within a tolerance of +/- 3 mm and the diameter within + 5 mm. The ends of a sleeve shall be

square to its centre line. 7.4.3. Washer Plates

The washer plates which are welded to the heads (or bottom nuts) of smaller diameter bolts to

prevent them from turning between the snugs on the anchor plate shall be grade S275 steel to

BS EN10025 unless specified otherwise. Washer plates shall be accurate in plan size within a

tolerance of plus 2 mm and minus 3 mm and the corners shall be square within a tolerance of

+/- 2 degrees. The thickness of plate shall be within normal rolling margins as specified in BS

EN10025. The plates shall be flat and free from warping.

7.4.4. Washers

Unless specified otherwise, standard washers shall be normal diameter black mild steel

washers to BS 4320. Where the holes in the base-plate are larger than normal clearance

holes, special washers will be required to details shown on the drawings; unless specified

otherwise these special washers shall be fabricated from grade S275 steel to BS EN10025.

Washers shall be provided under all bolt heads and nuts unless specified otherwise in writing

by the Engineer.

7.5. Protection of Threads

Holding down bolts shall be delivered to site with the threads protected against corrosion with

Type TP4 4a a Soft-film grease as specified in BS 1133: Section 6.

When the bolts have been cast-in, the bolt threads and the nut shall either be coated with

grease as specified above and then wrapped with a suitable thickness of flexible PVC

sheeting to BS1763, properly tied on, or else wrapped with layers of Denso tape.

7.6. Installation

7.6.1. The Contractor shall provide such temporary or permanent supports as are necessary to ensure that all bolts are cast in position within the requirements of this Specification. All bolts shall be held rigidly in position at top and bottom. Permanent supports, which project outside the finished concrete, shall be cut away to the Engineer’s approval. Steel templates with supports independent of the shuttering or reinforcement shall be used for bolts exceeding 48 mm diameter and/or length exceeding 1 metre.

7.7. Bolts in Sleeves

7.7.1. The position of the centre line of the bolt in plan at the top and bottom and at any level within the length of the bolt shall be accurate within the tolerance given in NSSS.

7.7.2. The sleeve for any bolt shall be concentric with the bolt within a tolerance of plus or minus 10 mm.

7.8. Protection of Bolts in Positions

Once cast in position, bolts shall be protected by the Contractor against damage from any

source until hand over.

7.9. Tightening

All holding down bolts shall be firmly tightened down. Care shall be taken not to damage bolts

by over tightening.

8.0. CORROSION PROTECTION

8.1. Surface Preparation

All steelwork shall be blast cleaned unless otherwise noted on the drawings. The surface

finish shall be in accordance with BS 4232 (2nd

quality) and to a visual standard in accordance

with SIS 055900 – Standard SA 2.5 at the time of painting.

8.2. Oil and grease patches on the surface must be removed prior to blasting.

8.3. Two coats of zinc phosphate primer shall be applied to a minimum total Dry Film Thickness of 115 microns in the workshop prior to delivery to site.

8.4. If blasting is carried out prior to fabrication then a post fabrication zinc phosphate primer shall be applied within 4 hours of blasting.

A further coat of High Build Zinc phosphate shall then be applied, prior to delivery, to bring the

total DFT to 115 microns. All grease, oil, debris shall be removed prior to the application of

the second coat.

8.5. The Contractor shall ensure compatibility of all paint coats and shall apply the paint strictly in

accordance with the manufacturers’ instruction.

Evidence shall be provided by the paint manufacturer, if required by the Engineer, that

specified coat thicknesses are being achieved. Testing shall be carried out by the paint

manufacturer at intervals agreed with the Engineer prior to commencement of the work. Test

results shall be made available immediately and a final report shall be submitted to the

Engineer on completion of the paint work.

8.6. Where remedial work is required on site due to welding or mechanical damage to the coatings,

power tool cleaning shall be employed to ensure that the material is cleaned to the same standard as for blast cleaning. This cleaning shall continue to a minimum of 25 mm into adjoining coated surfaces after which the base metal shall be coated with the same materials as have been used in the remainder of the steel to the same total thickness.

8.7. All steelwork within external cavity walls shall be painted with a minimum of three coats of RIW

or similar approved bituminous paint. More onerous requirements, where required, will be specified on the drawings.

SPECIFICATION

BRICKWORK and BLOCKWORK


acceptable.

1.0. SCOPE

1.1. This Specification covers the requirements, materials, workmanship and testing of

brickwork and blockwork.

1.2. Reference to the Engineer shall mean Ridge or the Architect as befits the case.

2.0. GENERAL

2.1. Brick and Block Samples

The Contractor will be required to build for approval sample panels, minimum 1 metre

square, of each type of facing brick and/or block and also of the various types and

colours of pointing, cavity work and insulation, wall ties, reinforcement and any other

special features to be built into the finished work. The number and variations of

sample panels to be built shall be agreed with the Engineer and the sample panels

built prior to the permanent works being commenced.

The approved panels shall be retained on site and used as standards until no longer

required by the Engineer.

2.2. British Standards

The work shall be carried out in accordance with the BS 5628 and all other relevant

British Standard. The latest additions together with all current amendments and

additions shall be used except as specifically varied herein or by the Engineer in

writing.

There shall be no deviation from this Specification without the prior written authority of

the Engineer.

3.0. MATERIALS

3.1. Certification

3.1.1. A copy of Certificates verifying that the materials comply with the Specification, and

containing the best results of the tests specified in the relevant British Standards, shall

be given by the Contractor to the Engineer at the intervals specified below unless

notified otherwise in writing.

3.1.2. Cement - each consignment.

Sand - each 10m3 or weekly, whichever is the more frequent, or

whenever the pit or area of the pit is changed.

Lime - each consignment.

Bricks & Blocks - each consignment.

3.2. Storage of Materials

3.2.1. General

3.2.1.1. All materials, i.e. Bricks, Blocks, Cement, Mortar, Sand, Lime, Ready Mixed Sand and

Lime, Damp Proof Courses, Bituminous Felts, Thermal Insulation materials, etc., shall

be stored/protected to the approval of the Engineer and in accordance with the

manufacturers’ recommendations and to ensure that they are protected from rain,

frost, snow and splashing from passing vehicles.

3.2.2. Bricks and Blocks

3.2.2.1. A suitable hard standing shall be prepared for storing bricks and blocks. They shall

not be offloaded by tipping from vehicles, but shall either be offloaded by hand or in

pallets by means of a forklift truck, crane or similar lifting device. They shall not be

stacked directly on sulphate bearing ground, clinker or ashes. They shall not be

stacked on newly cast slabs of concrete.

3.2.2.2. All bricks and blocks shall be arranged in orderly stacks and used approximately in the

order in which they are delivered, except in the case of facing bricks or blocks which

shall be intermingled so that any approved variation in colour or texture of different

consignments does not form defined areas in the completed work.

3.2.2.3. Stacks of bricks and blocks shall be arranged so that if they become accidentally

wetted, they can be dried out prior to use by forced circulation of air round the stack,

and so that in frosty and/or extremely cold weather, heat can be applied to the

material to ensure that the temperature of completed work shall not be lower than 5

degrees C.

3.2.2.4. Stacks of each type and strength of bricks and blocks shall be kept separate and

labelled accordingly. Broken and rejected bricks and blocks shall be stacked

separately and removed from site as soon as possible.

3.2.3. Cement

3.2.3.1. Cement purchased in bulk shall be stored in purpose built containers that are

maintained in good condition all to the approval of the Engineer.

3.2.3.2. Bag cement shall be stored off the ground in a well-ventilated, weather tight and damp

proof building.

3.2.3.3. The cement shall be stored in such a manner as to permit easy access for proper

inspection and identification of each consignment or type and shall be used in the

order of receipt.

3.2.4. Sand

3.2.4.1. Sand shall be stored on a clean flat prepared surface which allows adequate

drainage.

3.2.4.2. Sand shall be kept separate from other aggregates and away from other materials to

prevent contamination.

3.2.5. Lime and Ready Mixed Lime Sand Mixes

- Quick lime shall be delivered to the site as soon after manufacture as possible

and slaking commenced immediately. After slaking is completed, it should be

protected from drying out and remain undisturbed for a period of at least two

weeks prior to use to permit it to fatten up a lime putty.

- Hydrated lime shall be stored off the ground in a well-ventilated, weather-tight and

damp proof building.

- Ready mixed lime sand mortar shall be stored on a banker board and protected

from the rain and frost.

3.2.6. Metals (wall ties, reinforcement, damp proof course etc.)

Metals shall be protected by being stored under cover. Ferrous and non-ferrous

materials shall be kept separated and care shall be taken to prevent direct contact

between copper-bearing materials and aluminium or zinc.

3.2.7. Bituminous Felt

Bituminous Felt shall be stored on a level surface, away from heat, in such a manner

as to prevent damage by squashing.

3.3. Bricks and Blocks

3.3.1. The type, class, size, colour, finish and strength classification shall be as specified on

the drawings or contract schedules.

3.3.2. Concrete blocks shall be to BS 6073. Pt 1

3.3.3. Lightweight aggregate concrete blocks shall be to BS 6073: Pt.1. (where permitted).

3.3.4. Clay bricks shall be to BS 3921.

3.3.5. Shapes and dimensions of special bricks shall be to BS 4729.

3.3.6. The Contractor shall make sure that he understands clearly the Engineer’s

requirements for bricks and blocks before ordering or construction. If clarification is

required the Engineer’s ruling must be sought in writing and confirmation received

also in writing.

3.3.7. All bricks and blocks delivered to site shall be clearly marked identifying their intended

use as specified on the drawings or schedules.

3.4. Cement

3.4.1. Cement shall be ordinary or rapid hardening Portland cement to BS 12 or Portland

Blast furnace cement to BS 146 unless otherwise specified on the drawings/schedules

or in writing by the Engineer.

3.4.2. Coloured or white cement shall be to BS 12.

3.4.3. Sulphate resisting cement shall be to BS 4027.

3.4.4. Masonry cement shall be to BS 5224.

3.4.5. High Alumina cement shall not be used.

3.4.6. All cement delivered to site shall be clearly marked stating the name of the

manufacturer, the date of manufacture, the name of the material, i.e. ordinary or rapid

hardening Portland Cement, sulphate resisting cement or masonry cement, and the

number and year of the relevant British Standard to which the cement conforms.

3.5. Lime

3.5.1. Lime shall be made from limestone or chalk and shall be either :

- high calcium lime

- semi hydraulic lime

- magnesium lime.

3.5.2. The lime shall be classified as either :

- hydrated lime (powder)

- quick lime

and shall be to BS 890 Part 2 and Part 3 respectively.

3.5.3. Lime putty shall be to BS 890 Part 4.

3.5.4. Ready mixed lime sand for mortar shall be to BS 4721.

3.5.5. When coloured lime sand mortars are specified they shall conform to BS 4721

3.6. Sand

3.6.1. Sand for general purpose mortars shall conform to BS 1200, Table 1.

3.6.2. Sand for reinforced brickwork mortars shall conform to BS 1200, Table 2.

3.6.3. Sand, which has been in contact with seawater, loam or organic matter shall not be

used unless the Engineer’s permission is given in writing. It shall conform to BS 1200

and shall not contain any harmful materials that will adversely affect the hardening,

strength, durability or appearance of the finished work.

3.7. Water

3.7.1. Water shall be to BS 3148.

3.8. Admixtures

3.8.1. Plasticisers shall conform to BS 4887 and shall not be used without the written

approval of the Engineer.

3.8.2. All admixtures must be approved in writing by the Engineer and shall be used strictly

in accordance with the manufacturer’s recommendations.

3.9. Damp Proof Course

3.9.1. Materials for damp proof courses and damp proof details shall be in accordance with

the Architect’s details but the following general guides shall apply:

3.9.2. Bituminous felt shall be to BS 747.

3.9.3. Mastic asphalt shall be to BS 1097 (limestone aggregate) or BS 6577 (natural rock

asphalt).

3.9.4. Polythene sheeting shall be to BS 743 and have a thickness not less than 0.46mm

weighing about 0.48 kg/m2.

3.9.5. Slates, shall be to BS 743, consisting of at least two courses of sound whole slates

not less than 230mm in length laid to break joints and bedded in Class (ii)

cement/sand mortar.

3.9.6. Impervious bricks shall be to BS 743 and shall not absorb more than 3 per cent of

their weight when tested to BS 743.

3.9.7. Silicon based water repellents shall be to BS 3826.

3.10. Wall Ties

3.10.1. Ties for cavity walls shall be of Austenitic stainless steel to BS 1243, generally Type 1

to DD140 or as stated on the drawings.

3.10.2. Ties of galvanised mild steel, copper or other non-ferrous materials shall not be used

unless specified on the drawings.

3.10.3. Minimum length of ties shall be 100mm in excess of the width of the cavity.

3.10.4. Special metal ties or anchors shall be as detailed on the drawings.

3.11. Reinforcement

3.11.1. Reinforcement shall be as detailed on the drawings.

3.11.2. Expanded metal (steel) shall be to BS 405.

3.11.3. Steel fabric shall be to BS 4483.

3.11.4. Galvanising of Expanded Metal or Steel Fabric shall be to BS 729.

3.11.5. Steel bar reinforcement shall be to BS 4449 or BS 4482 as appropriate.

3.11.6. Stainless steel reinforcement shall be Austenitic stainless steel, minimum 18/8

composition and to BS 970: Part 4 or BS 1554 excluding free machining grades.

3.12. Lintols

3.12.1. Steel lintols shall be of hot dipped galvanised mild steel obtained from an approved

manufacturer to the size, length and profile stated on the drawings.

3.13 Joint Filling Sealant

3.13.1. Movement joint filling sealant shall be of the type and colour stated on the drawings

and shall be from a manufacturer approved by the Engineer.

3.13.2. Two part polysulphide based sealant shall be to BS 4245.

3.13.3. Testing of building sealant shall be carried out in accordance with BS 3712.

3.13.4. Joint filling strips shall be as stated on the drawings and from a manufacturer

approved by the Engineer.

4.0. WORKMANSHIP

4.1. Mortar

4.1.1. Mortar designation is specified by class number on drawings. Any type of mortar in

the same grade may be selected unless otherwise directed by the Engineer. Mortar

designation (iv) shall not be used except for non-load bearing internal walls.

4.1.2. Mortars shall be the proportions stated in Table 1 – BS 5628 Part 1.

4.1.3. Below damp proof course sulphate resisting cement shall be used unless otherwise

directed by the Engineer.

4.1.4. Proportions 5.1.5. proportions of mixes given in Table 1, BS 5628 Part 1 are to dry

sand. Allowance for bulking shall be made when gauging by volume.

4.1.5. In the absence of specific instructions on drawings, Table A (below) gives a guide to

the mortar designation to be used.

TABLE A

Construction Time of Construction Designation

Copings Winter (i)

Summer (i), (ii)

Parapets Winter (i),

Summer (i), (ii)

Retaining Walls Winter (i)

Summer (i), (ii)

Free-standing walls and Winter (i), (ii)

Building walls above DPC Summer (i), (ii), (iii)

Manholes Winter (i), (ii)

Summer (i), (ii), (iii)

Work Below DPC Winter (i), (ii)

Summer (i), (ii), (iii)

Reinforced Brickwork Winter (i)

Summer (i)

4.1.6. Mortar shall be mixed by a mechanical mixer or on a clean level banker board. The

constituents shall be thoroughly mixed so that they are evenly incorporated in the

mixture. Mortars containing plasticisers shall not be overmixed. Mixers shall be kept

clean at all times.

4.1.7. Mortar shall be used within about two hours of discharge from the mixer at normal

temperatures. In no case must mortar be used after the initial set has taken place.

Reconstitution of mortar shall not be permitted.

4.2. General

4.2.1. Work shall be carried out in accordance with the recommendations on workmanship in

BS 5628.

4.2.2. In dry weather clay bricks and blocks shall be wetted the minimum amount necessary

to prevent mortar drying out prematurely.

4.2.3. In cold weather, water and sand for mortar shall be preheated as necessary to ensure

a minimum temperature of 5 deg.C in the brickwork/blockwork when laid. The

temperature shall be maintained above freezing point until the mortar has fully

hardened. Frost damage to mortar shall be taken out and replaced and damaged

brickwork/blockwork shall be taken down and rebuilt as required by the Engineer.

4.2.4. All bricks subjected to severe exposure (e.g. in retaining walls, freestanding walls and

parapets) shall have frost resistance in accordance with the requirements of BS 3921.

Bricks with water absorption (boiling or vacuum) less than 7% or with compressive

strengths higher than 48.5 N/m2 shall be used in such cases.

4.2.5. In seasons liable to frost all brickwork laid during the day shall be properly covered up

with felt, sacking, boards or other approved non-conducting materials as the work

progresses and at night. In wet weather freshly laid brickwork/blockwork shall be

protected during periods of rain and at the completion of each day’s work.

4.3. Laying

4.3.1. Kiln fresh bricks shall not be used.

4.3.2. Facing bricks of varying colour or texture shall be evenly distributed throughout the

work so that no patches appear. Different deliveries, which vary in colour or texture,

shall be mixed to avoid any patching.

4.3.3. External facing brickwork shall commence at least two courses below finished ground

level.

4.3.4. Single frog bricks shall be laid with frog uppermost and double frog bricks shall be laid

with deeper frog uppermost. All Frogs shall be filled with mortar.

4.3.5. Brickwork shall be carried up in a uniform manner, no one portion being raised more

than 1200 mm above another at one time. All perpends and quoins shall be kept

strictly true and square and the whole shall be properly bonded together and levelled

round at each floor.

4.3.6. The maximum height of brickwork/blockwork that shall be built in a day is 1.5 metres.

4.3.7. Four courses of brickwork shall measure 300mm including four joints.

4.3.8. Bricks shall be laid on a full bed of mortar and all bed and perpend joints filled. Bed

and vertical joints shall be of equal and consistent thickness.

4.3.9. Blocks shall be laid on a full bed of mortar and all bed and perpend joints filled. Voids

in hollow blocks shall not be filled with mortar, unless stated otherwise on the

drawings.

4.3.10. Brickwork and blockwork shall be built to the following tolerances:

Tolerance on line

Panel length up to and including 5m +/- 10mm

Panel length over 5m up to and including 10m +/- 15mm

Panel length over 10m +/- 20mm.

Tolerance on height and level

Height up to and including 3m. +/- 5mm

Height over 3m up to and including 6m. +/- 15mm

Height over 6m. +/- 20mm.

Tolerance on plumb

Plumb of walls in any storey height. +/- 10mm.

Tolerance on Cavity

Width + 10mm

- 0mm.

4.3.11. Chasing of completed walls or the formation of holes shall be carried out only when

approved by the Engineer and after the brickwork/blockwork has set hard.

4.4. Bond

4.4.1. Except as specified in 4.4.2. brickwork one brick thick and over shall be built in

English bond and half brick walls including half brick leaves of cavity walls shall be in

stretcher bond.

4.4.2. Where a fair face on both faces of a wall one brick thick is required, each face shall be

in stretcher bond with suitable reinforcement to tie the leaves together.

4.4.3. Bricks shall be laid throughout the work with the cross-joints in any course not less

than a quarter of a brick from those in the course below. Half bricks or bats shall not

be used except where necessary for bonding.

4.4.4. Where dimensions do not permit normal bonding the Engineer shall be consulted

before bricklaying is commenced.

4.5. Joint Finishing

4.5.1. Unless otherwise specified internal work and faces which are not visible in finished

work shall be finished with a neat flush joint while the mortar is still green. When a

wall is to receive plaster, mortar joints shall be raked out to a depth of 13mm.

4.5.2. External facework pointing shall be as stated on the drawings. In the absence of other

instructions facework shall be finished with a neat struck weathered joint as the work

proceeds. Where the face joints have to be pointed, they shall be raked out to a depth

of 20mm. as the work proceeds and pointed to a desired finish with a mortar approved

colour in a continuous operation as scaffolding is taken down.

4.5.3. Movement joints shall be formed as shown on the drawings. Joint filling strip and

sealant shall be used strictly in accordance with the manufacturer’s recommendations.

4.6. Cavity Work

4.6.1. Cavities and ties shall be kept free from mortar and debris with battens or other

suitable through holes as necessary. Holes shall be made good after the clearing

operation.

4.6.2. Both leaves of cavity work shall be carried up together, with neither leaf more than

1200mm above the other.

4.6.3. Spacing of ties shall not be greater than stated in Table 6, BS 5628.

4.6.4. Wall ties shall be built in and not pushed in afterwards.

4.6.5. Adjacent to reveals of openings additional ties shall be used in a vertical line within

150mm from the opening edge and at the rate of one for each 300mm height.

4.6.6. Weepholes shall be formed in the outer skin by leaving open vertical joints at

approximately 900mm intervals at the base of the cavity and where the cavity is

bridged horizontally.

4.7. Damp Proof Course

4.7.1. Brickwork shall be build up flush with mortar to an even bed. The damp proof course

shall be laid horizontally on a mortar bed in continuous strips with 150mm laps in

length and full laps at angles. The joint shall then be completed to normal thickness

with mortar.

4.7.2. A Damp Proof Course as described on the drawings shall be provided around

openings in cavity walls in the following manner, unless detailed differently on

drawings ( refer also to 4.7.4.) :

- To head extending 100mm beyond end of lintols and

sloping to weepholes.

- To jambs fully lapped with horizontal d.p.c. at head and sill.

- Under jointed sills turned up at back and ends.

4.7.3. Damp proof courses shall finish flush with or projecting from the wall i.e. their edges

shall not be covered with mortar.

4.7.4. Notwithstanding anything in this specification all damp proof course and damp proof

membrane details shall be in accordance with the Architects requirements.

4.8. Ancillary Works

4.8.1. Doors and window frames shall be built into the brickwork as the work proceeds

unless otherwise directed by the Engineer. They shall be bedded in mortar similar to

that in adjacent work. Care shall be taken to ensure that damp proof courses are

positioned correctly in relation to the frame. Temporary frames will not be permitted

unless approved in writing by the Engineer.

4.8.2. Timber Pallet slips when used shall be treated with preservatives. They shall not be

used on external sections of cavity walls.

4.8.3. The top of non-load bearing walls shall be finished with a layer at least 10mm of easily

compressible material between the top of the wall and the soffit of the load-carrying

framework. If the joint is exposed it shall be sealed with a non-hardening mastic

sealant from an approved manufacturer.

5.0. TESTING

5.1. General

5.1.1. Testing Laboratory

The Contractor shall obtain the Engineer’s approval of the Laboratory in which

materials are to be tested. The Laboratory shall not be directly associated with the

Contractor’s organisation.

5.2. Testing Materials

When called for by the Engineer, tests shall be carried out on samples of cement,

lime, sand, bricks, blocks or water in accordance with the appropriate British

Standards and certificates produced.

5.3. Testing Mortar

5.3.1. Preliminary - in accordance with BS 5628 Part 1 Appendix A.

5.3.2. On-site - in accordance with BS 5628 Part 1 Appendix A.

SPECIFICATION

CONCRETE



1.1. This specification deals with the materials, design, workmanship and testing for mass

and reinforced cast – in situ concrete, mixed on or off site.

1.2. Reference to the Engineer shall mean Ridge and the contractor shall mean Main

Contractor.

2.0. GENERAL

2.1. All concrete work shall comply with the requirements of BS 8110 Structural use of

Concrete, (Section 6 and 7, of which shall be considered as part of this specification),

except where any of the requirements of this specification differ from those of BS

8110, in which case this specification takes precedence.

2.2. There shall be no deviation from this specification without the prior written approval of

the Engineer.

2.3. Concrete is specified in accordance with BS 8500, which shall be considered a part of

this specification, where applicable, except where it differs from this specification which takes precedence.

3.0. CONCRETE

3.1. Material

3.1.1. Certification

3.1.1.1. The Contractor shall provide the Engineer with the information referred to in BS 8500.

3.1.1.2. The Contractor shall obtain the Engineer’s approval of the materials testing laboratory.

3.1.2. Information

3.1.2.1. The Contractor shall, in good time, provide the Engineer with the information referred

to in Clause 5.2 of BS 8500-1. Changes in constituent materials shall not be made without prior written approval of the Engineer.

3.1.3. Cement

3.1.3.1. Cement shall be in accordance with British Standards given in Talk 1 of BS 8500-2.

Partial replacement with ground granulated blast furnace slag or pulverised fuel ash may be used with prior written approval of the Engineer.

3.1.3.2. Chemical analysis of the cement and aggregates to be used in the mixes shall be

provided and checked that the criteria for no alkali aggregate reactions occurring given in BS 8500-2 clause 5.2 are met.

3.1.4. Aggregates

3.1.4.1. Aggregates shall comply with BS EN12620 and BS EN13055-1.

3.1.4.2. Marine aggregates shall only be used with the prior written approval of the Engineer.

The chloride content of the aggregate shall satisfy BS EN206-1 and that of the concrete BS 8110 Clause 6.2.5.

3.1.4.3. Dolerites, Whinstones and other aggregates with high drying shrinkage shall only be

used with the prior written approval of the Engineer.

3.1.5. Admixtures

3.1.5.1. Admixtures shall only be used with the prior written approval of the Engineer. Neither

calcium chloride nor any admixture containing it shall be proposed.

3.1.6. Mixes

3.1.6.1. The grades of concrete are as shown on the drawings in accordance with BS 8500.

All grades are designed mixes unless otherwise noted.

3.1.6.2. The proportion of the ingredients of the concrete, including the water, shall be so

chosen that the concrete will be workable enough to be fully compacted and not be prone to segregation or bleeding.

3.1.6.3. The minimum cement content shall be as specified on the drawings.The maximum

cement content shall be 550 kg/m3.

3.1.6.4. The Contractor shall provide suitable evidence of satisfactory performance of all grades of concrete specified. This may be in the form of existing data and shall include details of the water cement ratio, mix details and characteristic strengths.

3.1.6.5. Unless specially authorised by the Engineer, the concrete shall be mixed and the

water added to the mixer at the depot. No additional water shall be added at any stage from batching to placing. When the Engineer is asked to authorise dry batching he will require to be satisfied that appropriate steps will be taken to ensure the quality, consistency and strength of the concrete as placed and that the water will be added to the dry ingredients under properly controlled conditions.

3.1.6.6. The drum of the truck agitator or truck mixer shall be completely clean and empty

before it is filled with concrete. Trucks shall not be loaded in excess of the manufacturer’s rated capacity, which shall be displayed on the vehicle in terms of the volume of mixed concrete. Trucks shall be discharged within two hours after the introduction of the water to the cement unless a longer time is authorised by the Engineer.

3.1.6.7. The actual batched weight of cement, water and coarse and fine aggregates and the

time of introduction of the water shall be recorded on each delivery ticket by the supplier. When concrete is wet batched no water shall be added after batching.

3.1.7. Transport

3.1.7.1. Concrete shall be transported from the mixer to the formwork as rapidly as practicable

by methods which will ensure that at the point of deposition it is of the correct quality and consistency.

3.1.7.2. Containers used for transporting concrete made from Portland Cement, shall be free

from any concrete or mortar containing high alumina or super sulphated cement.

3.1.7.3. The Contractor shall provide a simple identification label of the grade of concrete

being transported.

3.1.8. Placing Concrete

3.1.8.1. Formwork shall be free of all deleterious material during concrete placement.

3.1.8.2. When concrete is to be placed on or against the ground it shall be done immediately

following the final preparation of the formation. When this is not practicable the formation shall be protected by blinding or other methods to the Engineer’s approval.

3.1.8.3. Immediately prior to re-commencement of concreting at a joint, the surface of the

existing concrete shall be free from laitance and shall be roughened so that the tips of the largest aggregate are exposed but not disturbed. This surface shall be prepared when the concrete has set but not hardened, by spraying with a fine spray of water or brushing with a stiff brush, which is sufficient to remove the outer mortar skin. Where this treatment is impracticable, sand blasting or a needle gun shall be used to remove the surfacing and laitance; hacking of hardened surfaces shall be avoided. The joint surface shall be cleaned immediately before the fresh concrete is placed against it.

3.1.8.4. No extra water shall be added to the mix after the concrete has left the mixer.

3.1.8.5. Concrete shall be placed continuously up to all joints. Particular care shall be taken in

the placing of the new concrete close to joints. This concrete shall be fully compacted with a vibrator, where possible.

3.1.8.6. Concrete in slabs on ground shall be placed in long strips with crack inducing joints.

Where this is not practicable the Contractor shall submit his proposals to the Engineer for approval.

3.1.8.7. Concrete for walls shall be placed in successive pours working away in both directions

from the first panel cast, which preferably will be near the centre, not in hit-or-miss sequence nor with shrinkage gaps except for a final closure. The minimum interval between placing adjacent panels shall be 3 days unless directed otherwise.

3.1.8.8. Concrete shall not be placed by any method which causes segregation, undesirable

finish or defective structural quality. It shall not be moved into position by rakes or vibrators. Chutes, skips, hoppers etc. shall be kept free from coatings of hardened concrete and shall not be wetted during use.

3.1.8.9. If a delay exceeding one hour occurs during the concreting of a floor slab or beam,

concreting shall be completed against a newly placed stopend. If this joint is not in a satisfactory position the Engineer will require the concrete to be cut back to an acceptable position.

3.1.8.10. In massive sections due to allowance shall be made for the effect of lift height on the

temperature rise due to the heat of hydration. The Contractor shall submit proposals to minimise these effects for the Engineer’s approval.

3.1.9. Construction Joints

3.1.9.1. Construction joints shall be deemed to include stopends and crack inducing joints (for

movement joints see section 4).

3.1.9.2. Construction joints shall be at right angles to the member. Formed joints shall be

plain unless a key is specifically detailed on the drawings or called for by the Engineer. The reinforcement shall continue through the joints unless directed otherwise. Should the Contractor wish to incorporate waterbars when he has not been directed to, his proposals require the Engineer’s approval.

3.1.9.3. Joints shall be located to meet the requirements of the finish, e.g. granolithic finish on

floors. Joints in columns shall only be formed about 15mm above the soffits of suspended floors, at floor levels, or at the tops of kickers which shall not be less than 75mm high. There may be a joint between haunches or column capitals and the column.

3.1.9.4. Concrete in kickers shall be of the same mix as the main member. The concrete shall

be vibrated or rammed into place and prepared as for other joints.

3.1.9.5. Horizontal joints in walls which are designed to be continuous with the floor slabs shall

only be formed at the top of a kicker which shall be placed intergrally; the kicker shall

not be less than 75mm high. No further horizontal joints shall be formed; this may necessitate a special design for the formwork.

3.1.9.6. Horizontal joints in other walls shall only be formed at the soffits of suspended floors

(including splays) at floor levels, at the top of kickers (which shall not be less than 75mm high) and above major openings.

3.1.9.7. The Contractor’s proposals for the location of construction joints shall be based on the

following guide-lines :

(a) The number of construction joints should be kept as few as possible

consistent with reasonable precautions against the effects of shrinkage; their location shall take due account of shear and other stresses. Joint lines shall be arranged so that they coincide with feature of the finished work.

(b) Joints in slabs on ground should be aligned with column or grid lines

whenever practicable and separation shall be provided around columns.

(c) Joints in unreinforced slabs on ground (including slabs nominally reinforced

with not more than 0.1% steel in either direction) shall be at centres not greater than 5m.

(d) Joints in suspended beams, if required, shall be between the one- quarter and

one-third points of the span unless otherwise directed by the Engineer.

(e) Joints in a suspended floor system, if required, shall be between the one-quarter and one-third points of the span unless otherwise directed by the Engineer. It is preferable that no joints are formed in end bays.

(f) Vertical joints in walls generally should not be spaced at intervals greater than 10m and in no case shall be more than 12m. Where, however, a wall changes direction by at least 60 degrees, the overall spacing of joints may be increased to 20m subject to the length of pour in either leg of the wall being not more than 10m. Where possible joints should be positioned at least 2m away from corners.

3.1.10. Compacting Concrete

3.1.10.1. When directed by the Engineer the Contractor shall demonstrate the efficiency of the proposed method of construction on a trial section, prior to the commencement of the permanent works.

3.1.11. Finishing Formed Surfaces

3.1.11.1. All surfaces shall be free from voids, honeycombing or other large blemishes. The holes left by formwork bolts shall be filled. Fins and irregularities projecting more than 3mm shall be cleaned off, except in the case of concealed surfaces such as those permanently buried.

3.1.11.2. All forms shall be true to shape and free from defects likely to detract from the general appearance of the finished concrete surface. All formwork materials for exposed concrete work shall be approved by the Engineer in writing.

3.1.11.3. Finishes are specified on the drawings in accordance with BS 8110 Clause 6.10 and

shall be Type A if not otherwise specified.

3.1.12. Finishes Unformed Surfaces

3.1.12.1. The finish of unformed surfaces shall be tamped, floated, trowelled or brushed as

defined below and shown on the drawings.

TAMPED finish shall be formed by levelling and tamping the concrete to produce a

uniform, plain or ridged surface, surplus concrete being struck off by a straight edge

immediately after compaction. It is also the first stage of the following finishes :

FLOATED finish shall be a uniform surface which has been worked no more than is

necessary to remove screed marks by hand with a wood float or by power float of a

type approved by the Engineer. The surface shall not be floated until the concrete has

hardened sufficiently.

STEEL TROWELLED finish shall be a hard, smooth finish free from trowel marks

formed with a steel trowel under firm pressure. Trowelling shall not commence until

the moisture film has disappeared and the concrete has hardened sufficiently to

prevent excess laitance from being worked to the surface. If laitance is brought to the

surface it shall be removed.

BRUSHED finish shall be formed before the concrete has hardened by drawing a wire

broom over the concrete surface at right angles to the traffic flow to give an average

texture depth of 1mm.

3.1.13. Dimensional Tolerances

3.1.13.1. The concrete work shall be constructed to an accuracy, which shall permit the proper assembly of components and installations and shall be compatible with the finish. The accuracy of the work shall be within the tolerances stated on the drawings or specified elsewhere and, in the absence of any other requirements, shall comply with the following :

All setting out dimensions +/- 5mm

Sections of concrete members +/- 5mm

Surfaces of foundations against ground (underside) + 5mm / -100mm

Top surfaces of foundations, bases and piers + 5 mm/ - 20 mm

Surface level of floor slabs (3m straight edge) +/- 3mm

Surface level of floor slabs to datum +/- 10mm

Position of bolt pockets (mean of set) +/- 5mm

Position of bolt pockets (to mean)

(measured at surface of foundation) +/- 5mm

3.1.14. Curing Concrete

3.1.14.1. The concrete shall be protected from adverse weather conditions after placing. It shall

be cured to ensure that it has satisfactory durability and strength, the minimum of distortion, freedom from excessive efflorescence and will not cause by its shrinkage undue cracking the structure.

3.1.14.2. Surfaces shall be cured for the minimum period specified in BS 8110 Section 6.6.

3.1.14.3. The Contractor shall inform the Engineer of his proposals for curing including details

of any membranes or surface treatments.

3.1.14.4. The Contractor shall ensure that any membrane curing compounds applied to the

surface are compatible with finishes or other treatments specified on the drawings.

3.1.14.5. Where structural members are of considerable depth or bulk or have an unusually

high proportion of cement or the concrete incorporates admixtures or is subjected to special or accelerated curing methods, the method of curing requires the approval of the Engineer.

3.1.14.6. Alternate wetting and drying shall be avoided, especially in the form of cold water

applied to warm concrete surfaces. In order to avoid surface cracking cold water shall not be applied to relatively massive members immediately after striking the formwork while the concrete is still warm.

3.1.15. Protecting Concrete

3.1.15.1. Concrete shall be protected to prevent damage from weather, plant, overloading or

any other cause.

3.1.15.2. Before making good any damage the Contractor shall obtain the Engineer’s approval

of the methods and materials proposed.

3.1.15.3. Concrete shall not be cut without the prior approval of the Engineer.

3.1.15.4. In cold weather bolt pockets shall be packed to prevent water entering.

3.2. Compliance

3.2.1. Evidence shall be submitted in the form of trial mixes or previous data that the proposed mix proportions satisfy the specification.

3.2.2. Concrete will be assessed for compliance in accordance with the procedures

described in Annex A of BS 8500-2. Sampling rate shall be one for every 25m3 of

every mix of concrete cast but not less than 1 sample for each mix for each day that is used.

3.2.3. A minimum of four specimens shall be made from each sample and tested as follows:

(a) Two specimens at 28 days with the average of the results being taken as the test result.

(b) Two specimens at 7 days or an alternative period proposed by the Contractor and approved by the Engineer should the Contractor wish to predict 28 days’ strength. The average of the two tests shall be taken as the test result.

The 28 day test shall be the test upon which compliance or “otherwise” is decided.

3.2.4. In the event of non-compliance the course of action shall be as directed by the

Engineer.

3.3. Reporting the Results of Tests

3.3.1. The reports of the tests for strength shall embody the information required by BS 1881 : Part 115-125, together with the information listed below:- (1) Name of contract. (2) Identification of mixer or ready mix supplier and depot. (3) Grade of concrete. (4) Type of cement. (5) Section of work represented by sample. (6) Added water. (7) Density of cube (kg/m

3).

3.3.2. Single copies of the completed report forms shall be dispatched direct to the Engineer

upon completion of each test.

3.3.3. A record of the statistical checks shall be supplied to the Engineer when each is

prepared.

4.0. MOVEMENT JOINTS

4.1. General

4.1.1. Movement joints are those which are designed to permit relative movement of

adjacent parts of a member or structure without impairing its structural integrity.

4.1.2. Movement joints shall be formed in the locations and to the details shown on the

drawings.

4.2. Materials

4.2.1. General

The materials forming the joint require the Engineer’s approval except when their use

is directed by name; when seeking approval the Contractor shall provide full technical

data and a sample.

4.2.2. Dowel Bars

Dowel bars shall be straight round steel bars which comply with BS 4449 and which

have no deformations. They shall be free from burrs and other irregularities.

4.2.3. Joint Filler

Joint filler shall be as specified on the drawings and in the absence of guidance shall

be a compressed sheet of cork granules bonded with bitumen or synthetic resins.

4.2.4. Joint Sealant

Joint sealant shall be as specified on the drawings.

4.3. Workmanship

4.3.1. Joints shall not be sealed until the concrete adjacent to the joint is at least 28 days

old.

4.3.2. Dowel bars shall be rigidly supported so that they are parallel and in the same plane.

4.3.3. The joint and adjoining surfaces shall be dry and thoroughly cleaned of all grease, oil,

release agents, dust and other foreign matter by grit blasting or wire brushing before the joint materials are placed. Surfaces shall not be cleaned with acid.

4.3.4. All jointing materials shall be applied strictly in accordance with the manufacturer’s

recommendations including the use of any associates materials and the curing of the completed seal.

5.0. REINFORCEMENT

5.1. Materials

5.1.1. The Contractor shall, on demand, provide the Engineer with certificates verifying that

the reinforcement complies with specifications in accordance with BS 4482, BS 4449

and BS 4483.

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