Blockwork Spec

8/2/2019 Blockwork Spec

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SPECIFICATIONFOR CONSTRUCTION RELATED WORKSSERIES 2400

BRICKWORK, BLOCKWORK AND STONEWORK


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C Highway Term Maintenance Contract - 2007 - Contract Documentlume 3 - Construction Related Works - Specificationes 2400 - Brickwork, Blockwork and Stoneworkt update - 17 April, 2007ntout date - 23 June, 2008e location - p;\highmgmt\termcont\htmc 2007 - contract documentswolume 3 - specifications - cd\crw - specification -

cd\spec _2400 - cd.doc


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Highway Term Maintenance ContractSpecification for Construction Related Works Series 2400Brickwork, Blockwork and Stonework

Contents

2401 Cement SP-2400-12402 Aggregates SP-2400-12403 Water SP-2400-12404 Cement Mortar SP-2400-12405 Lime Mortar SP-2400-22406 Bricks SP-2400-22407 Blocks SP-2400-22408 Reconstructed Stone SP-2400-32409 Natural Stone SP-2400-32410 Reinforcement SP-2400-32411 Anchorages, Dowels, Fixings and Ties SP-2400-32412 Brickwork and Blockwork SP-2400-32413 Stonework SP-2400-42414 Cold Weather Working SP-2400-52415 Protection of New Work SP-2400-52416 Brick, Block and Stone Facework Fixed to Concrete SP-2400-52417 NotUsed SP-2400-62470 Brick and Stone on Existing Structures SP-2400-62471 Taking down existing Brickwork and Stonework SP-2400-6

Devon County Council- Environment, Economy and Culture Directorate[Date issued - 01110/2006- Contract Document] SP-2400-i


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ries 2400ickwork, Blockwork and Stonework

Highway Term Maintenance ContractSpecification for Construction Related Works

Devon County Council - Environment, Economy and Culture Directorate[Date issued - 01/10/2006 - Contract Document]


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Series 2400Brickwork, Blockwork and Stonework

2401 Cement

2401.1 Cement shall be one of the following:(i) Portland cement complying with BS 12;or

(ii) "Wallcrete" masonry cement as manufactured by Blue Circle Cement Co or equivalent;or

(iii) Sulphate-resisting Portland cement complying with BS 4027 where instructed in the Task Order.

2402 Aggregates2402.1 Fine aggregate for cement mortar shall comply with BS EN 13139 Grade 0/ 2 Category 3 and a suitable fine

aggregate can be obtained from Hanson's Heathfield Pit near Kingsteighton, Devon.2402.2 Fine aggregate for lime mortar shall comply with BS EN 13139 Grade 0/ 2 Category 3. Itshall also be clean,

sharp and well graded. Itshould contain a small proportion of grit with the maximum particle size (normally 3to 5 rum) of approximately 1 1 3 of the joint width. A grading certificate to BS EN 13139 shall be submitted tothe S er vi ce Manager for approval.

2403 Water2403.1 If water for the Works is not available from a water company's supply, the Contractor shall ensure that the

water complies with the guidance given inBS EN 1008. The sulphate content of the water shall be tested inaccordance with Test No.1 inTRL Report 447. The water shall not be used if the sulphate content exceeds1.4 g of sulphate (as S04) perlitre. Water from the sea or tidal rivers shall not be used.

2404 Cement Mortar2404.1 Cement mortar for brickwork, blockwork and stonework shall be mixed in the proportions given in Table

24/1 for mortar designation (tv) unless otherwise described in the Task Order.2404.2 The chloride ion content of the mortar determined in accordance with BS EN 1744-1 shall not exceed 0.3%

of the mass of cement for mortar made with Portland cement and 0.2% for mortar made with sulphate-resisting Portland cement. Calcium chloride or admixtures containing calcium chloride shall not be used.

2404.3 For work in which cement mortars of designation (ii) or (iii) as defined in BS 5628: Part 3 are required, theContractor shall select the appropriate mortar from one of the mixes for the designation given inTable 24/1.If the work is to be carried out in frosty weather and the bricks are wet when laid, then a cement sand mortarwith an air entraining plasticiser shall be used. Admixtures shall comply with either BS EN 934-3 and shallnot contain calcium chloride.

2404.4 The inclusion of lime in mortar designation (i) is optional. The proportions of lime given in Table 2411 arefor lime putty complying with BS EN 459-1. If the lime is measured as the dry hydrate, the amount may beincreased up to 1.5 volumes for each volume of lime putty. Where a range of sand contents is given in theTable, the higher shall be used for sand that is well graded and the lower for coarse or uniformly fme sand.

2404.5 Mortar shall be mixed thoroughly either by hand or mechanically until its colour and consistency are uniform.The constituent materials shall be accurately gauged, allowance being made for bulking of sand. Mortar shallbe made in small quantities only as and when required. Mortar which has begun to set or which has beenmixed for a period of more than one hour in the case of a mortar designation (i) or more than two hours in thecase of other designations shall be discarded.

Devon County Council - Environment, Economy and Culture Directorate[Date issued - 01/10/2006 - Contract Document]

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TABLE 24/1: Mortar Proportions by Volume

Mortar designation Cement: lime: sand Masonry cement: Cement: sand withsand plasticiser(i) I : 0 to J , 4 : 3 -- --(ii) 1 : Yz : 4 to 4Yz 1:2Yzt03Yz 1 : 3 to 4(iii) 1:1:5t06 1:4Yz 1 : 5 to 6(iv) -- 1: 4 --

05 Lime Mortar05.1 Lime mortar shall consist of one part by volume of hydrated lime complying with BS EN 459-1 to 2.5 parts

by volume of sand or one part by volume of Natural Hydraulic Lime grade NHL 2, NHL 3.5 or NHL 5complying with BS EN 459-1 to 2.5 parts by volume of sand.

05.2 Mortar shall be mixed thoroughly, avoiding balling, until its colour and consistency are uniform. The limemanufacturer's instructions shall be followed. The constituent materials shall be accurately gauged, allowancebeing made for bulking of sand. Mortar shall be made in small quantities only as and when required. Mortarmust be used within 2 hours. Reworking of the mortar, following manufacturer's instructions, is allowablewith approval of the Service Manager.

05.3 Where pozzolan or colouring is required, they shall be described in the Task Order. The addition ofpozzolanfor cold weather working will require the approval of the Service Manager ..

06 Bricks06.1 Clay bricks shall comply with the particular requirements of BS EN 771-1 and as described in the Task

Order. The determination of sulphate content for the soluble salt content test shall be in accordance with TestNo.2 in TRL Report 447.

06.2 Calcium silicate bricks (sand lime and flint lime) shall comply with BS 187.06.3 Concrete bricks shall comply with BS 6073: Part 1.06.4 Bricks beneath frames for chambers and gullies, and for the construction of brick chambers, shall, unless

otherwise described in the Task Order, be HD Type Class B clay engineering bricks conforming with BS EN771-1 and the performance characteristics given inTable 24/2; or concrete bricks complying with BS 6073:Part 1 having a crushing strength not less than 20 N/mm2 when used for surface water drainage, or specialpurpose concrete bricks having a minimum cement content of 350 kg/m' when used for foul drainage.

07 Blocks07.1 Concrete blocks shall comply with the particular requirements of BS 6073: Part 1 and BS EN 772-2 as

described in the Task Order.

TABLE 24/2: Performance Characteristics Requirements of Engineering BricksPerformance Characteristics Reference Clay engineering bricks

Class BCompressive strength (N/mm2) BS EN 772-1 ?75

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Water absorption (% by mass) and also when used as BS EN 7720-7 5:J.0 (and DPC2)DPCunitsand and andNet dry density (kg/rrr') BS EN 772-13 ~100Freeze/thaw resistance category BS EN 772-1 F2Active soluble salts content category BS EN 772-5 S2

2408 Reconstructed Stone2408.1 Reconstructed stone shall be used only in blockwork and shall comply with BS 6457 and any particular

requirements described in the Task Order.

2409 Natural Stone2409.1 Building stone shall be of the type and quality described in the Task Order.

2410 Reinforcement2410.1 Wire or fabric, laid between brickwork or blockwork shall be austenitic stainless steel to BS EN 10088-1,

designated 1.4301, 1.4401 or 1.4436, softened condition, excluding free machining specifications.2410.2 Steel bars laid between brickwork or blockwork shall be austenitic stainless steel to BS 6744, designation

1.4301 or 1.4436, softened condition, excluding free machining specifications.

2411 Anchorages; Dowels; Fixings and Ties2411.1 Anchorages, dowels, fixings and ties shall he stainless steel designation 1.4301, 1.4401 or 1.4436, softened

condition, excluding free machining specifications, complying with the requirements given in the BritishStandards listed in Table 24/3.

TABLE 24/3: Austenitic Stainless SteelForm Standard to be complied with

Strip BS EN 10029, BS EN 100481, BS EN 10051,BS EN 10258, BS EN 10259

Rod BS EN 10088-1Bar BS 6744Tube BS 6323-8Wire BS 1554

2412 Brickwork and BIockwork2412.1 Brickwork and blockwork shall be laid on a full bed of mortar and bonded as required in the Task Order.

Single frogged bricks shall be laid with the frog uppermost, Perpends between bricks and blocks shall be

Devon County Council - Environment, Economy and Culture Directorate[Date issued - 0 1/1 0J 20 06 - Contract Document]

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filled with mortar before the next mortar bed is laid. Whole bricks and blocks shall be used except where it isnecessary to cut closers.

12.2 Brickwork and blockwork shall be built uniformly. Comers and other advanced worle shall be stepped backand not raised above the general1evel more than 900mm. Courses shall be kept horizontal and matchingperpends shall be in vertical alignment.

12.3 Unless stated in the Task Order, overhand work shall not be permitted.12.4 Bed-joint reinforcement shall have a 15mm minimum of mortar cover to each masonry face. It shall not be

laid dry on a bed face, but shall be embedded within the mortar bed thickness.12.5 Joints in brickwork and blockwork shall be raked out to a depth of 12mm and after the completion of the

entire facework, pointed, struck flush and brushed unless otherwise instructed by the Service Manager. Oncompletion the face of bricks and blocks shall be clean and free from mortar and staining of any kind.

12.6 Where jointing is required in the Task Order it shall be done as the work proceeds to the finish described inthe Task Order.

13 StoneworkGeneral

13.1 Except where otherwise described in the Task Order, the length of any stone shall not exceed three times itsheight. The breadth on the bed shall be not less than 150mm, nor greater than three-quarters of the thicknessof the wall.

13.2 All stratified stone possessing bedding planes shall be laid with its natural bed as nearly as possible at rightangles to the direction ofload. Inthe case of arch rings, the natural bed shall be radial.13.3 Facework quoins shall be built to a height not exceeding 900mm in advance of the main body of the work and

adjacent walling stepped down on either side.13.4 Stone facework between the quoins shall then be built to a height not exceeding 450mm above the backing

which shall then be brought up level with the completed facework. At no time shall the backing be built uphigher than the facework. .

13.5 (i) All joints shall be kept to a minimum but sufficiently thick to prevent stone-to-stone contact and shallbe completely filled with mortar.

(ii) Unless otherwise instructed by the Service Manager, the joint shall be recessed and dressed in one ofthe following ways dependent on the mortar used:(a) Cement - The joint shall be recessed sufficiently to provide a clear outline of each stone. Thedepth of the recess shall be between 8mm and 15mm depending on the average size of the stone; thesmaller the stone the shallower the recess. The profile of the finished pointing within the recess shallhave a flat surface to give a clearly defined line between the stone and the pointing. After the mortarhas reached its initial set it shall be brushed to remove the laitence and expose the aggregate.(b) Lime - Where the stones have well defined and sharp edges the joint shall be flush pointed. Inall other cases the joint shall be slightly recessed so that the mortar does not spread over the roundededges of the stone. The profile of the finished pointing within the recess shall have a flat surface togive a clearly defined line between the stone and the pointing. After the initial set the mortar face willbe 'weathered' to match the existing pointing or as approved by the Service Manager, in one of thefollowing ways.e Light spray with water and possibly brush with a soft brush to show the aggregate;

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stipple with a stiff brush; dab with coarse sacking.

(iii) On completion the face of the stone shall be clean and free from mortar and staining of any kind.Ashlar

2413.6 All stones shall be dressed to accurate planes on the beds and joints, and they shall be fair and neatly or finetooled on the face as described in the Task Order.Random Rubble Coursed and Uncoursed

2413.7 All stones shall be carefully set with a bond stone provided at the rate of not less than one to every squaremetre of exposed face. Bond stones shall measure not less than 150rum x 150mm on the exposed face, andnot less than 450mm in length or the full thickness of the wall if the latter is less than 450mm unless otherwisedescribed in the Task Order. For coursed work the joints shall be levelled as described in the Task Order andthe backing flushed up in mortar.

2414 Cold Weather Working2414.1 No bricks, blocks or stones shalI be laid when the air temperature in the shade is below 3C with cement

mortar or 5C with lime mortar unless precautions are taken either in accordance with BS 5628-3 or to ensurethat all materials when used are free from snow, ice and frost.

2414.2 If there is a danger of freezing of fresh or uncured lime mortar, close covering with Hessian or tarpaulins andif necessary heating should be provided. Polythene should not come incontact with fresh lime mortar.

2415 Protection of New Work2415.1 Immediately after laying and for 3 days thereafter, brickwork, blockwork and stonework using cement mortar

shall be protected against the harmful effects of weather. The upper surface of newly laid brickwork,blockwork and stonework shall be protected against rain as the work proceeds until such time as the work iscompleted and the upper damp-course, coping or other finishing feature is laid.

2415.2 All visible brickwork, blockwork and stonework and any surface below such work which is visible at thecompletion of the Works shall be clean and free from damage and spillage. All purpose-made open jointsshall be free from debris of any description.

2415.3 Lime mortar is to be kept moist for 7 days to allow it to cure properly.2415.4 Immediately after laying brickwork, blockwork and stonework using lime mortar protection, against theharmful effects of weather, should be in place for as long as necessary for the lime mortar to firstly cure

properly and then dry sufficiently. The upper surface of newly laid brickwork, blockwork and stonework shallbe protected against rain as the work proceeds until such time as the work is completed and the upperdamp-course, coping or other finishing feature is laid.

2416 Brick, Block and Stone Facework Fixed to Concrete2416.1 Any loose material shall be removed from the concrete, and its surface washed with clean water before any

bricks, blocks or masonry is laid.2416.2 The portion of the stainless steel fixing projecting from the concrete shall be completely embedded in the

mortar of the facework and shall be kept back a minimum of 30rum from the face of the brickwork andblockwork or 40mm from the face of the masonry.

Devon County Council- Environment, Economy and Culture Directorate[Date issued - 0 11 10 /2 00 6 - Contract Document]

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ries 2400ickwork, BIockwork and Stonework


The cavity between brick and block facework and the concrete shall be completely filled as the workproceeds with mortar of the same mix. as that specified for the facework.

The variation in depth, front to back of stones for natural stone facework shall not exceed that described inthe Task Order and the space between the facework and the backing shall be completely filled as the workproceeds with concrete Class 15/10 complying with the 1700 Series.

417 Not Used470 Brick and Stone on Existing Structures

Where required on existing structures, brick and stone shall be of a type and appearance to match the originalconstruction and shall require the approval ofthe Service Manager before work commences.

71 Taking down existing Brickwork and StoneworkIn taking down existing brickwork and stonework, every care shall be taken to preserve the arrises.Bricks and stones suitable for re-use shall be cleaned of existing mortar and stored.The method employed in taking down the brickwork or stonework shall not in any way affect the structuralintegrity of the structure.

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Devon County Council - Environment, Economy and Culture Directorate SP-2400-7

Documents

Blockwork Spec