BDA Comment On The Use Of Reclaimed Clay Bricks

2y ago
9 Views
2 Downloads
3.05 MB
28 Pages
Last View : 2m ago
Last Download : 2m ago
Upload by : Ellie Forte
Transcription

BDA comment on the use ofReclaimed Clay BricksJanuary 2014

The BDA offers the advice in good faith, bricks are durable and therefore sustainableand reusable. While it is true that bricks that have been produced under EN 771-1 inrecent years are likely to last for 150 years this may not be true of recycled bricks.Bricks reused require to be tested and qualified to confirm that they are suitable for thepurpose intended. It is not advised that bricks are reused without testing unless theyhave been produced to EN 771-1. The Construction Skills (CITB) have worked with theBDA to produce this document. The BDA are very grateful for their assistance.2 BDA Guide on the use of Reclaimed Clay Bricks

“ Bricks reused are required to be tested and specifiedto confirm they are suitable for the purpose intended ”IntroductionThe advantages of specifying new bricksare that they are made to an establishedstandard, BS EN 771-1, “Specification forClay Bricks”. There is a wide selectionavailable and they are typically more costeffective than reclaimed bricks.The appeal of using reclaimed bricks is that they mayhave developed a particular character, being fullymatured and weathered. Depending on the situationit may be more “environmentally friendly” to use areclaimed brick. Currently reclaimed bricks have acertain cachet; they are less widely available, moreexpensive and have a distinctive appearance.The following notes raise points to consider whencomparing reclaimed bricks with new, and describethe process of reclaiming bricks.Interior of the completed Holmesdale projectTeddington Case StudyBDA Guide on the use of Reclaimed Clay Bricks 3

“ Old brickwork often has a pleasingweathered appearance or natural patina ”Technical AppearanceTraditional Method Of Manufacture andCurrent MethodsMany specifiers choose reclaimed bricks in themistaken belief that bricks of similar appearance arenot available as newly manufactured materials. Inparticular, they are not aware that handmade bricksare still currently manufactured.Many tolerate the distressed state of reused brick,resulting from the process of reclamation, in thebelief that there is no alternative. Several companiesdo continue to make handmade bricks however;some are traditionally clamp fired and produced inexactly the same way as brick makers have done forcenturies. Other companies have developed simulatedhandmade bricks which look handmade but have beenmanufactured by modern machine methods.Weathered Appearance: Tips forToning Down New BricksOld brickwork often has a pleasing weatheredappearance or natural patina, suggesting that thereuse of reclaimed brick is the best way to obtain a4 BDA Guide on the use of Reclaimed Clay Bricksmature character to newly built work.New brickwork may stand out from established work, butit can be treated to tone it in. One method of doing this isto apply a soot wash made by soaking a sack of soot in acontainer of water and applying washes to the brick untilthe required degree of darkening has been achieved.Commercial wash preparations are now available thatperform the same function and advice can be obtainedfrom English Heritage regarding their application.Experimenting on a trial area first is wise, applyingwashes to the brick until the required degree of darkeninghas been achieved. In practice it is best not to tone thebrickwork too much as the surface of new brickwork willdarken naturally. Alternatively there are a wide variety ofcommercial tints and colours which can be used to alteror match a brick finish.These commercial tints generally are both successfuland long lasting prior to the natural aging process takingover. Brick tinting using modern materials are best carriedout by experts in the field with previous experience. It isalways advised to test a small unimportant or samplepanel before making a commitment for more extensivework.Another method which may be used in rural areas isto apply a solution of either soaked cow pats (manure)in water, or yogurt or sour milk in water. This promotesthe growth of lichens and mosses and encourages anecosystem into the wall surface.

“ Specifiers should check that their indemnity insurancepolicies cover the specification of reclaimed brick ”Reclaimed Brick Aesthetic:Distressed BricksMany reclaimed bricks often possess a distinctdistressed appearance as a result of the process ofreclamation.For some it is this very characteristic that makesthem attractive or imparts a mature character tothe brickwork. In recent years, some manufacturershave developed brick products that look as thoughthey have been reclaimed, with chipped arises, paintremnants and random dark stains.Simulated reclaimed bricks are made by applying‘attractive’ disfigurements to bricks during themanufacturing process in the form of paint marks,whitewash, etc., and sometimes ‘tumbling” them toachieve the distressed appearance.They have the great advantage of being made toconform to current European Standards and arecompetitively priced because they are mass produced.Suitability of Old Bricks for New WorkReclaimed bricks may be selected for aestheticreasons, but they must be technically appropriatefor new work.A further consideration might be that spores of dry rotfungus could be present in bricks reclaimed from somelocations.Many dealers supply reclaimed bricks graded byquality of appearance but cannot guarantee durability.In the absence of any specific assurance regarding thedurability of particular reclaimed bricks they should beused with caution.Specifiers should check that their indemnity insurancepolicies cover the specification of reclaimed brick, asthese products are not in accordance with a BritishStandard.If Planning Officers stipulate the exclusive use ofreclaimed bricks in planning consents, specifiers arerecommended to check with their insurers beforecomplying with the Planning Office requirements.Frost resistance, soluble salts, strength, waterabsorption and size are all items that are covered byBS EN 771-1 and only new clay bricks are covered bythis standard as all the relevant tests relate to samplesdrawn from newly manufactured consignments.BDA Guide on the use of Reclaimed Clay Bricks 5

“ Non frost resistant are only suitable forinternal use and are seldom made today ”Frost ResistanceClay bricks are made from a great variety ofnatural clay deposits which together with the firingcharacteristics of the manufacturing process governa brick’s frost resistance. With reclaimed bricks thereis difficulty in assessing frost resistance.A sample of bricks can be subjected to a freezethaw cycle test, but the results of this test cannotbe extended to classify the whole consignment asconsistency of quality within it cannot be fully known.Assessing strength and high density (low porosityor low water absorption) will not guarantee frostresistance. Strong and dense bricks of Engineeringclass are very often frost resistant, while others of lowstrength and low density (high porosity or high waterabsorption) may also be frost resistant. To assumethat because a brick is old it must have proven frostresistance is incorrect.6 BDA Guide on the use of Reclaimed Clay BricksBefore the early part of the 20th century, brickmanufacturers would have assessed bricks as theywere drawn from the kiln. From the manufacturer’sexperience of the brick making material, the brickswould have been sorted on the basis of durability.Bricklayers too, with their experience of locally availablematerials, would have gained the ability to judge therelative frost resistance of well fired and less well firedbricks when selecting them for particular locations.They would have selected the bricks appropriate forthe face of a wall and those adequate to only use inprotected inner walls or partitions of buildings.When a building is demolished, the bricks beingreclaimed may become mixed up with the non frostresistant ones. Non frost resistant are only suitable forinternal use. Before the commonplace use of concreteblocks, such bricks were frequently used in buildingsfor internal walls. Often they are a salmon pink incolour and do not make a clear ringing sound if tappedagainst each other. They could still be used internally.

“ Greater variation within the properties of areclaimed material should be expected ”Unfortunately no standardised guidelines or Codesof Practice currently exist to state the method bywhich bricks should be reclaimed. Consequentlyone cannot be sure of the durability of reclaimedbricks. Ideally the supplier should provide reliableassurance that their reclaimed bricks have beentaken exclusively from external walling. In general,only if it is known the bricks have been obtainedfrom an exposed situation should they be treatedas frost resistant. It is possible in the future that anEU approved testing facility could develop a Codeof Practice, based upon inspection, sampling andtesting of bricks from a single site which could givegreater confidence in their durability. Selectingnew bricks with regards to frost resistance is morestraightforward as they are classified in BS EN 771-1into categories of frost resistance. This standard andPD 6697:2010 (Recommendations for the Designof Masonry Structures to BS EN 1996-1 and BS EN1996-2) explains what frost resistance requirementsare required in various building situations.Note and link to be inserted herewhen DRIDS project is completeSoluble Salts ContentSoluble salts can be present in reclaimed bricksbecause they naturally occur in certain clays, andbecause the bricks may have become contaminatedwith salts during their service life, for example bysulphates absorbed from the soil leaching up intothe brickwork, or by sulphates absorbed from theproducts of combustion into bricks used in chimneys.They may also be contaminated during reclamation orstorage. With any of these cases there is no way ofknowing the salt content of a reclaimed brick exceptperhaps from the dealer’s knowledge of the origin ofthe brick.New bricks are classified by three categories of solublesalts content defined in BS EN 771-1. This is importantto know in order to specify the mortar. Category S0has no requirement; Category S1 bricks have definedlow limits placed on the contents of acid-solublesulphates and water-soluble, magnesium, potassiumand sodium. Category S2 bricks are subject to morestringent limits.Where there is a high risk of brickwork becomingsaturated for substantial periods of time there can be arisk of sulphate attack on the mortar. This is a reactioninvolving a constituent of the Portland cement andsulphate salts in solution. The result is crumbling anddisintegrating of mortar joints. It is sensible to treatreclaimed bricks as Category S1 bricks.EfflorescenceIt is possible that reclaimed bricks may have watersoluble salts contained within them. For this reason,to reduce the risk of efflorescence, the sameguidance contained in codes of practice relating toworkmanship for new work continues to apply whenusing reclaimed bricks.BDA Guide on the use of Reclaimed Clay Bricks 7

“ Reclaimed special shaped bricks are not readily available,but can be manufactured new if a match is required ”StrengthNo assurance can be obtained regarding thestrength of particular reclaimed bricks. Modernbricks are classified by the crushing strength inrelation to a sample taken from bulk quantities ofnewly manufactured bricks and it would be generallyimpractical to adopt this method for the assessmentof the crushing strength of reclaimed bricks.Modern bricks are made by more controlledmanufacturing methods than those of former timesand consistency of the product is achieved. Greatervariation within the properties of a reclaimed materialshould be expected. However, for two-storey and threestorey domestic construction it is unlikely that strengthrequirements would limit the use of reclaimed brick.Water AbsorptionThe water absorption of a clay brick is significant.In the calculation of flexural strength in the designof structural brickwork, no guarantee can be giventhat samples of reclaimed bricks truly representa consignment of consistent units in this regard.However, this characteristic is unlikely to limitthe application of reclaimed bricks in the types ofconstruction for which they are commonly proposed.Movement JointsAlthough the irreversible moisture movement thatoccurs during the life of clay bricks will generally havetaken place in reclaimed bricks, brickwork built withthem will still be subject to cyclic thermal movement.Therefore movement joints should be provided asrecommended in PD 6697, particularly for south andwest facing elevations and when the construction isthe outer leaf of a cavity wall fully filled with cavityinsulation, or another insulated construction.SizesReclaimed bricks may often be used because itis assumed that new bricks are made in one size.Since metrication, standard bricks have been madeto conform to a British Standard metric size (215 x102.5 x 65mm). However, most manufacturers makeand hold in stock bricks of various Imperial sizes.These can be used to course with existing Imperialdimensioned work, in which case it is the height ofthe unit that has most significance. The most commonimperial compatible bricks are 80mm, 73mm (2 7/8”)67mm (2 5/8”) 50mm (2”) high. The majority ofthese bricks are 215mm long and 102.5mm wide, butmanufacturers can make any size required.8 BDA Guide on the use of Reclaimed Clay BricksA selection of standard specials is covered by BS 4729,“Clay bricks of special shapes and sizes”.The metric standard brick size was adopted in 1974;it is slightly smaller than the former Imperial standardbrick adopted in 1965 (8 5/8” x 4 1/8” x 2 5/8’) (219 x104.8 x 66.8mm).Before 1965 two standard heights were adopted inthe 1920s by the Royal Institute of British Architects(RIBA): 2 5/8” (66.8mm) allowing four courses to rise12” (305mm) and 2 7/8” (73mm) allowing four coursesto rise 13” (33Omm).They became known as the Southern and Northernbricks respectively, based on common regional usage.Prior to 1904 when the RIBA initially adopted theSouthern Brick Standard there were no standards, onlypopularly used sizes.Up to as late as 1965 many bricks did not conformto the standards mentioned above. Whether newor reclaimed Imperial sized bricks are selected tomatch existing work it is advisable to check detaileddimensions in relation to the size of the chosen brickto establish nominal work size. Traditional bricks hadgreater size variability.This should be considered when undertaking a newscheme as the bricklayer’s craft skills will become ofgreater significance in attaining a good job. Also checkthat there are sufficient supplies available to completethe work.If using Imperial bricks with a standard metric concreteblock inner skin, adjustable wall ties may be requiredto overcome the differences in alignment of the bedjoints created between the two. When using reclaimedbricks of 1965 Imperial standard size in metric gaugedbrickwork - i.e. four courses to 300mm - horizontal bedjoints will be thinner compared with when traditionallygauged (four courses to 12”) or when using metricbricks at four courses to 300mm. It should beappreciated that this will affect the overall appearanceof the brickwork.PavingFor use as paving, clay pavers must be fully frostresistant. Reclaimed pavers can be used with confidence,providing they have been previously laid in an areawhere they have been fully exposed to the weather.Great caution is advised in considering whetherreclaimed walling bricks might be suitable for paving.

“ Today bricks are produced by technically more efficient andenvironmentally conscious methods than they were in the past ”Environmental IssuesConcern exists about what constitutes bestenvironmental practice. Ultimately this is a matterfor the user to evaluate especially if this is a majorconsideration in specification. The merits of using areclaimed brick should be judged on an individualbasis, looking particularly at the key issues of theavailability of the proposed brick and its location.The Building Research Establishment’s “Green Guide toSpecification” suggests that a greater capacity existsfor recycling bricks, but recycling may not representbest environmental practice especially where costlyand polluting energy resources are consumed inreclamation. BRE found that using reclaimed bricksin their new Centre for Building Heritage was not, inreality, best environmental practice because of thehaulage costs to their site.Some new brickwork could be built with lime mortarswith the intention that at a later date the bricks canbe more easily reclaimed. Lime mortars are generallynot strong enough to conform to the current designrequirements of some modern brickwork especially fortaller construction unsupported at every floor level.Today bricks are produced by technically moreefficient and environmentally conscious methodsthan they were in the past. For current levels of brickproduction, the rate of extraction amounts to no morethan 1% of the tonnage of quarried materials in theUK. As clay deposits are usually of great depth theyuse up relatively small areas of land. Also deposits arefrequently adjacent to the brick making factories andso transport impacts are minimised.All bricks have the ability to be recycled as gradedaggregates for use in sub-bases, hard-core and forconcrete. Other applications include crushing intogranules for use with composites and into brick dustfor use in lime mortars and in brick tinting.The embodied energy content of brickwork is lowin relation to the energy used within a building in anormal life span of 150 years and particularly low forthe very long life characteristically observed for brickbuildings. Clay bricks can also be reused.The UK industry currently produces around two billionclay bricks per year. Over the last 20 years the energyrequirement for their manufacture has been reducedby over 20%. Manufacturing performance is monitoredand reported annually as part of the BDA SustainabilityKey Performance Indicators. Also the emissions fromthe firing process have been greatly reduced. The UKbrick industry uses large quantities of appropriaterecycled raw material classified as MARSS (Materialsfrom Alternative Recycled and Secondary Sources).BDA Guide on the use of Reclaimed Clay Bricks 9

“ Currently in the UK there are over 1200 typesof brick made from many different types of clay ”Reclaiming Brick The ProcessCleaning Off MortarBricks of theVictorian Periodand earlier (i.e.pre early 20thCentury) wouldnormallybejointed in lime/sandmortarwhich is easiertoremovefrom the brickthanmodernPortland cement / sand mortar. Nevertheless, goodlime mortar can form a tenacious bond with thebricks and removal needs patience and hard workwith a heavy hammer and broad cold chisel or bolsterfor large lumps of mortar and a brick hammer (onewith a replaceable hardened claw steel tip is useful)for dislodging smaller pieces.Rubbing bricks on an abrasive grit stone may be usefulfor truing up some surfaces. The use of power toolsis not advised as grinding wheels or discs and wirebrushes are difficult to control and scoring or polishingcan easily disfigure a brick’s surface.For restoration work where the use of the hydrauliclime/sand mortar would be desirable, hydraulic limecan be obtained from a specialist supplier who canalso offer guidance on the relative proportioning oftraditional mortar mixes.http://www.buildinglimesforum.org.uk/If there is no need to use traditional lime mortar then oldbricks can be satisfactorily laid with Portland cement/sand mortars. The particular mix of mortar shouldbe chosen in relation to the exposure of the wallingor paving in question and guidance on this selectionis given in the BDA’s design note no.7 January 2011Brickwork rk-durability/Matching Colour and TextureSometimes it is assumed that because a building isold the only way to match a brick is by using onethat is reclaimed. It is interesting to note that whenHampton Court and Kew Palace have bricks replacednew bricks are specified, albeit made to the particularsizes and special shapes required. Specialist brickmakers who are members of the BDA have a largeproportion of their output devoted to historic repair.Chemical CleaningProprietary, branded brick cleaning solutions aregenerally based on dilute hydrochloric acid and maybe used to remove stubborn mortar or lime stainsfrom the face of bricks. Care must be taken to wet thebricks first to reduce surface absorption and preventpenetration of the acid into the brick (reference BDA“Cleaning of Brickwork” Publications).The use of hydrochloric acid, or any other chemical,is not recommended for the initial removal of solidmortar.MortarTraditionally old brickwork was laid with hydrauliclime and sand mortar. This was particularlyappropriate for the thick walls that characterisedolder forms of construction, but it is not normalmodern practice.10 BDA Guide on the use of Reclaimed Clay BricksHampton Court PalaceCurrently in the UK there are over 1200 types of brickmade from many different types of clay. The colour andtexture of clay bricks are essentially dependent on themanufacturing method and the firing characteristics ofthe clay. It is quite feasible that a suitable match can befound within these ranges.

“ Specialist brick makers who are members of the BDA havea large proportion of their output devoted to historic repair. ”Stabilisation of old brick surfaceWhile the great majority of properly fired brick willeasily reach 150 years life not all older bricks weremade to our modern standards, bricks may also havedamage from salt from gritting especially at low leveladjoining pavements or roads. Chemical pollutionfrom decades in an industrial environment may havealtered the matrix of the brick face. You are advisedto confirm the reused brick is free of these defects.If the brick face is friable or starts to flake when usedinternally the alternatives are if possible a very brief(none saturating power wash) but only if the area islarge and access is difficult. We suggest it is preferableto brush with a stiff bristle brush not a wire brush toremove all debris. After a brick is wetted efflorescenceis always possible even with an older brick but this isnot a permanent condition.it dries clear but unfortunately does give an initial slightsheen which will weather off in time.We suggest a small area is tested and monitoredbefore extensive work. Of course reclaimed brickscome in a huge variety of compressive strengths, waterabsorbency, textures and finishes so no one solution issuitable for all bricks or conditions and the user mustcontact the manufacturer to confirm the suitability orfor larger projects carry out their own testing. http://www.ceram.com/The conservation approach is to then used a lime washwhich is binding, breathable and, non invasive. A coatConclusionThe use of reclaimed bricks should not be discouragedprovided that users are conscious of their qualitiesand are able to correctly evaluate their fitness forpurpose in the context of the proposed application.Their high cost is a reflection of demand and the costof reclamation, rather than the intrinsic quality of thematerial.of properly applied lime wash is largely translucent andthe form and texture of the bricks will still be visible.Alternatively a lime render can bind the surface but ofcourse the appearance brick is lost. The wall will stillbe breathable to avoid the build up and retention ofcondensation.A modern alternative is a silane/siloxane based waterrepellent which the makers claim still enables the brickto breathe as it lines the pores of the brick as opposedto providing a coating this is applied as a white creamUsers should also be aware that new clay bricks areavailable in a very wide range of colours, textures,sizes and shapes, enabling a good match to be foundfor most existing brickwork. Many manufacturers alsoproduce simulated reclaimed bricks if “distressed”characteristics are required. New bricks are made toconform to quality standards and physical propertiesspecified by British Standards. They are generally muchless costly than reclaimed bricks because of efficiencyin contemporary production. New bricks made to BSEN 771-1:2011 can be used with the confidence thatthey may be reused in the future up to and beyond the150 year life.BDA Guide on the use of Reclaimed Clay Bricks 11

“ Overall the percentage waste was low with 30% onyellow stock and only 10% on rubbed reds ”Teddington Case StudyThis interesting project took down a humdrum existingproperty built in the 1880s and rebuilt it using partnew and 40 sq metres reclaimed bricks which wereprocessed on site. Overall the percentage waste waslow with 30% on yellow stock and only 10% on rubbedreds. The rear and side elevations of this excitingmodern property are built with new bricks. But inorder for the front elevation of the property to fit inwith the surrounding Teddington houses reused bricksare used.Fortunately the surrounding properties have highceiling heights and the front design was acceptableto the modern house developer and architect. Severalproblems had to be overcome including coursingheights and mortar mixes which is always an issuewhen dealing with older reclaimed bricks of uncertainprovidence. The end result is an attractive modernhouse which also proves the sustainability of thereclaimed brick by reusing what was found on site.Rear elevation of the completed Holmesdale project Teddington Case Study12 BDA Guide on the use of Reclaimed Clay Bricks

“ Several problems had to be overcomeincluding coursing heights and mortar mixes ”Salvage of the Holmesdale project begins Teddington Case StudyGreat use of reused yellow stock for the Holmesdale project Teddington Case StudyPhotocredits: Dennis Gilbert VIEW / Mel Yates / McDaniel WoolfCredit: Main Construction [ Main Contractor ] and Malishev Wilson Structural EngineersBDA Guide on the use of Reclaimed Clay Bricks 13

“ Much of the cellar is Roman origin and the Norman keephas reused bricks forming the string courses ”Colchester Castle Case StudyColchestertheformerRomanCamulodunum and sometime capital ofRoman Britain was sacked and burnt byBoudica the Warrior Queen of the Iceniwho in alliance with the Trinovantes triberevolted against their former Romanallies. Colchester Castle is on the site ofthe last stand of the discharged RomanLegionnaires who fell defending the templeof Claudius in around AD 60.Much of the current cellar is Roman inorigin and the Norman Keep has reusedbricks forming the string courses and thestructural elements of the external walls.These reused bricks have been through firepetulance and war and are yet approachingtheir 2000 year, a fitting statement on thedurability of brick. These bricks are still asattractive as laid 1000 years ago for thesecond time by the Normans as they builtthe Keep to exclude the Viking raiderspenetrating up the nearby Colne River.Few if any natural but worked materialsare as natural or can demonstrate similarlongevity. The length of years that a bricklasts also rather minimises its Carbonimpact!14 BDA Guide on the use of Reclaimed Clay Bricks

“ These bricks are still as attractive as laid 1000 years agofor the second time by the Normans ”BDA Guide on the use of Reclaimed Clay Bricks 15

“ Great use was made of building materials from the remainsof the local Roman city of Verulamium, mostly brick and flint ”The Cathedral and Abbey Church of Saint AlbanFrom its elevated situation on the site of the execution and burial of St Alban, our first British martyr, the Abbeychurch of St Alban has dominated its surroundings for over 900 years. It is a building of contrast, architecturalstyles from the Saxon period through to the great Victorian restoration and a 20th century Chapter house.The only Saxon work now in the Abbey can be seen in the shafts up in the triforium (first floor gallery) of boththe North and South TranseptsThe Norman rebuilding of the Abbey Church began in 1077. Great use was made of building materials from theremains of the local Roman city of Verulamium, mostly brick and flint, along with blocks of limestone possiblyfrom Barnack in Lincolnshire. The brick and flint structure was plastered throughout giving an ideal surface forpainting.What is now left of this early Norman work carried out during the abbacy of Paul of Caen, is the magnificenttower, the transepts (with some later alterations), the north and three bays of the south nave and aisles, andparts of the presbytery walls. The great tower is 144 feet high, weighing about 5000 tons above the piers, whichthemselves are founded on limestone, still visible beneath the south west pier.16 BDA Guide on the use of Reclaimed Clay Bricks

“ The brick and flint structure was plastered throughoutgiving an ideal surface for painting ”BDA Guide on the use of Reclaimed Clay Bricks 17

“ The only building is the nave of the priory church, built withmuch reused brick and stone from the Roman town ”The Priory of St. BotolphThe Priory of St Julian and St Botolph was foundedin 1103 by a community of priests who had previouslyserved an important church of this site. The dedicationof St Botolph, an East Anglian abbot who died in 680indicates a Saxon origin for the community.The only building to survive is the nave of the priorychurch, built with much reused brick and stone fromthe Roman town. The circular piers are strengthened bytriple courses of brick and the shallow pilaster runningup from the capitals mark the division of the bays andthe position of the roof tie beams. At the west end, thegreat “Screen Facade” can be dated to circa 1160. Theeastern half of the church does not survive, but its planwas revealed by an archaeological excavation in theearly 1990s. The cloister lay to the south

2 BDA Guide on the use of Reclaimed Clay Bricks The BDA offers the advice in good faith, bricks are durable and therefore sustainable and reusable. While it is true that bricks that have been produced under EN 771-1 in recent years are likely to last for 150 years this may not be true of recycled bricks.

Related Documents:

May 02, 2018 · D. Program Evaluation ͟The organization has provided a description of the framework for how each program will be evaluated. The framework should include all the elements below: ͟The evaluation methods are cost-effective for the organization ͟Quantitative and qualitative data is being collected (at Basics tier, data collection must have begun)

Silat is a combative art of self-defense and survival rooted from Matay archipelago. It was traced at thé early of Langkasuka Kingdom (2nd century CE) till thé reign of Melaka (Malaysia) Sultanate era (13th century). Silat has now evolved to become part of social culture and tradition with thé appearance of a fine physical and spiritual .

On an exceptional basis, Member States may request UNESCO to provide thé candidates with access to thé platform so they can complète thé form by themselves. Thèse requests must be addressed to esd rize unesco. or by 15 A ril 2021 UNESCO will provide thé nomineewith accessto thé platform via their émail address.

̶The leading indicator of employee engagement is based on the quality of the relationship between employee and supervisor Empower your managers! ̶Help them understand the impact on the organization ̶Share important changes, plan options, tasks, and deadlines ̶Provide key messages and talking points ̶Prepare them to answer employee questions

Dr. Sunita Bharatwal** Dr. Pawan Garga*** Abstract Customer satisfaction is derived from thè functionalities and values, a product or Service can provide. The current study aims to segregate thè dimensions of ordine Service quality and gather insights on its impact on web shopping. The trends of purchases have

Chính Văn.- Còn đức Thế tôn thì tuệ giác cực kỳ trong sạch 8: hiện hành bất nhị 9, đạt đến vô tướng 10, đứng vào chỗ đứng của các đức Thế tôn 11, thể hiện tính bình đẳng của các Ngài, đến chỗ không còn chướng ngại 12, giáo pháp không thể khuynh đảo, tâm thức không bị cản trở, cái được

The Business Data Architecture (BDA) has been updated and released at intervals and this is the seventh BDA release. Each release is considered a “cut” of the continuingly evolving data architecture. Up until BDA version six (the sixth “cut”), a new version was createdwhen significant changes had been made to the Business Data Architecture to warrant a new “cut”. BDA version six .

BDA Broadband Drop Amplifier The BDA Broadband Telecommunications Drop Amplifier is a two‐way 1 GHz amplifier designed for customer premise amplification. These amplifiers can be used to compensate for long drops and excessive splitting losses. Each BDA is housed within a robust