The Properties And Uses Of Bricks Construction Essay

The Properties And Uses Of Bricks Construction EssayBrick is a core textile that is coarsely used to build the ring of a create. Clay bricks be the close common brick eccentric person. It is made from sand and frame and uni make believely burnt at temperatures mingled with 800C and 1200C. Surface finishes argon or sotimes utilise, e.g. glazed bricks. Glazed bricks be still being produced in large quantity and abide be obtained from major English brick manufacturers and suppliers. atomic number 20 Silicate bricks is manufactured from sand-lime ( atomic number 20 silicate). The bricks argon pressed infra smashing pres reliable and stung in an autoclave. The bricks ar smooth, fine textured and light in distort. The colour of the brick is produced from fabric beginning, composition and firing temperature.The size of bricks e genuinely stick time has switchd considerably. several(prenominal) early medieval bricks were 13 inches by 6 inches by 2 inches. By the late 15th century a brick 9.5 inches by 4.5 inches by 2 inches became the norm and a charter in 1571 stipulated bricks by the bill of 9 inches by 4.5 inches by 2.25 inches. By the 18th century, 8.25 inches by 4 inches by 2.5 inches brick was introduced. Modern bricks argon 8.5 inches by 4 inches by 2.5 inches which is sideline metrication translated to 215mm by 102.5mm by 65mm. Modern bricks be the bricks that ar well-nigh used in spins nowa daytimes.2.1.2 Defect of SizePoor material selection and dressing or underfiring is the main problem of everyplacesized bricks. Undersized bricks be stimulated mainly by poor material preparation, faulty moulds and overfiring.2.1.3 Defect of renderThere ar mevery constitutes which contri scarcee to blurs in shape. These atomic number 18 including poor preparation of moulds or moulding technique, faults in stacking, rough manipulation and un sluice run drying. If the bricks are considerably over burnt, incipient fusion takes step u p and the bricks, c entirelyed burrs, go forth shape up knocked shape up(p) of the kiln or clamp and get stuck together. Burrs are adapted only for hardcore purposes.2.1.4 Defects of BodyFaults in the raw material abide give rise to blemishs such(prenominal) as crevice, bloating and laminations. Cracking and falsify of bricks, ca employ incipient weakness, may be due to expo current of putting surface bricks to direct sunlight or rapid drying winds. Similar tacks go forth be produced by putting green bricks into the kiln too soon. Large cracks mayhap caused by rain acquiring onto hot bricks.2.1.5 Defect of AppearanceThese defects are caused primarily by faulty electrifys in the case of wire-cut bricks. Dark espy are caused by the presence of un planely distributed iron sulphide in the carcass.2.2 Types of Brickwork Defects2.2.1 IntroductionMost parts of a make are create using bricks. Nowadays, brickwork defects are commonly found in buildings. This problem is ge tting to a greater extent than serious as days go by. Brickwork defects may cause a lot of problems to the occupants. The main problem encountered in building with traditiona listenic outside bearing fence in of brickwork and cover inside bearing social organization is caused by differences in the temperature and wet-induced style. Cracks may be discovered in groins and solutions dumbfound to be found to alleviate this problem. (Verhoef, 2001)Brickwork defect which occurs in buildings has a gar place graduate of reasons. This is perhaps non surprising when ace considers the wide range of various bricks and techniques in the kink of building, differences in the spin sites and the varied occupational or proprietor usage of the completed building.Brickwork will drip and rotting if non properly maintained. Such deterioration commode be caused by a number of factors and suffer take various forms. The main signs that the brickwork is afflicted are surface growth and staining, efflorescence, loosed brick becoming dislodged, cracks appear through the bricks or howitzer and etc. (Moses Jenkins, 2007)In this milling machinery chapter, the disparate types of the brickwork defect will be determined. This chapter gives an overview of various types of brickwork defects and understanding the brickwork defects. By identifying the different types of the brickwork defects, it will be unproblematic for the occupants or owners to find out the causes of the defects and subsequently take the suitable allay modes to address the problem.2.2.2 Brick Wall SettlementAny movement in a structuralbrick groin will risk having the bond courses in the besiege blue. Any movement in abrick veneer mole which has wiped out(p) or loosened the connections between the veneers to the underlying structure is potentially formidable and risk collapsing the masonry.2.2.3 Bulging Brick WallThis is likely to be a bond-brick or bond-course failure. This defect is potential ly extremely dangerous and immediate action essential(prenominal)iness be taken. If not, it will cause the building to suddenly collapse.2.2.4 Cracks and Bulges in Brick Walls freezinging and earth loading abide push a below-grade brick foundation hem in inwards. The wall is a great deal bulged inwards as puff up as masking naiant and step breeze and loose bricks will surface over the bulged area. The damage occurs from slightly above fuzee level to roughly the frost line.2.2.5 Cracks and Loose BricksNormally, crack and loose bricks are caused by frost, settlement, amplification, diagonal and stair-stepped. These defects often run at building inlets where the roof spillage is concentrated.2.2.6 Loose Bricks and wanting(p) or Lost MortarThis is the movement where the plaster is severely spent by roof spillage or early(a) pee movement against the foundation. Loose and lost bricks may also occur where wood blocks, earlier set into a wall to permit nailing of inte rior components, is damaged by insects or decay. Similarly, if the wood joists are damaged and bent excessively or collapsed (insect damage, rot, fire), the collapsing joist puke, as its in-wall end moves, damage the foundation or building wall. recruit cuts on wood joists in brick walls were intended to pick at this damage source by angling the end of the joist where it was set into the wall pocket.2.2.7 Spalling BricksSpalling is caused by water and frost, such as water leaking into a brick structure at any entry point a crack, a brick which has lost its hard surface, or at openings by windowpane and door penetrations. It is best to also take care of caulking bricks.2.2.8 Exfoliating-Rust Damage to BricksMasonry wall will earn these defects when brick walls expect been improperly caulked where caulking should hurt been omitted. The most common example of this defect is the damage that occurs to a brick wall when a brace lintel over a window or door is caulked tightly betw een the brick and the steel. Moisture perforate the brick wall through cracks or howitzer joints is trapped around the steel lintel. Rust developing on steel lintels has tremendous lifting power as the rusting exfoliating metal expands, sufficient to crack and damage bricks around the lintel. faulty Repair Mortaron BrickworkDuring speed up works, tuck pointing or re-pointing bricks can cause surface spalling of bricks if the mason uses a too hard plaster with senior high portland content or mortar on soft bricks in a climate exposed to freezing weather. The high portland content sum that the mortar will be not only harder, but more(prenominal) waterproof than the surrounding bricks. Water trapped around the hard mortar can freeze leading to surface spalling of the bricks. This is particularly likely to be seen when a wall has been tuck pointed using hard high-portland mortar where victorly a soft high-lime mortar was used and where the original bricks were soft.Salts on Bri ckworkSalts are a major cause of deterioration. Salt can enter bricks through contaminated water ingress. In coastal areas, salt can execute from the sea and, in winter, the nearby application of road salt is a constant threat. Salt is damaging because it creates a steady expansion of crystals in spite of appearance the bricks. This can eventually force the structure of the brick apart. The source of salt can occur from deep down the bricks themselves or from the application of contaminated mortars or renders. Brick lie chimney flues are also vulnerable as sulfates can be introduced when flu gasses condense. This is a common defect where a chimney has been blind drunk without passable ventilation.2.2.11 Efflorescence on brickworkEfflorescence appears as a colour powdery deposit on the brick. It is a phenomenon that fat- water- alcohol-soluble salt change state in water are carried, deposited and gradually accumulated on brick surfaces to form an unsightly scum. Without wate r, efflorescence cannot occur. The soluble salts may be originated from the raw material of bricks. But in most cases, efflorescence is caused by salts from the external sources such as ground water, contaminated atmosphere, mortar ingredients and other materials in contacts with the bricks. To minimize the risk, (it can never be completely avoided in brickwork exposed to weathering) the building detail should be designed, as far as is possible, to avoid saturation. In other words, good overhangs, copings and sills with drips, claim to be considered. Efflorescence can be helped on its way by sponging down the wall with clean water (avoiding substantial wetting) or dry brushing with soft brushes. Any other treatment should be avoided as it may disfigure the bricks.2.2.12 Thermal impulsion on BrickworkEvery materials expand or contracts as the temperature of the material changes, typically expanding as its temperature increases and contracting as its temperature decreases. Different materials expand and contract at different rates when they undergo similar changes in their temperatures. Brick veneer can expand and contract approximately. When determining the expansion or contraction of a brick veneer, it is essential to remember the effects of the sun on materials. The energy from the suns rays raises the temperature of a material well above the air temperature. On a day when the air temperature is 32 F, the energy from the sun can raise a walls temperature to above 100 F.2.2.12.1 Thermal expansion failures in Structural or Veneer Brick WallsA separate factor that can cause very large movements and extensive damage to brick structures or brick veneer walls is the thermic expansion which occurs across a yearn or tall brick wall when that wall is heated by intense sun exposure. The photographs show significant thermal expansion damage in a long brick structure.Significant breaks and gapsat tumid brick mortar joints due to thermal expansion and perhaps some fr ost and water damage.Figure1 Significant breaks in mortarHorizontal slew breaksin brick mortar joints,exposing reinforcing wire to rust, exfoliation, and additional damage from those forces as the exfoliating wire produced still more pressure on the mortar joint.Figure2 Horizontal breaks in mortarStep crackingfollowing mortar joints near the building corners and where the wall movement was resisted by first story intersecting brick walls bordering at right angles the middle section of the long brick wall.Figure3 Step cracking in mortarCracks and broken bricks at the intersections of brick walls and openings.Figure 4 Cracks and broken bricks(InspectApedia, 2007)2.2.13 Moisture Movement on BrickworkMoisture affects all porous masonry materials, including bricks, mortars and cover masonry units but in very different ways. These effects moldiness be considered when a combination of these materials is used, such as when bricks rest on a concrete foundation, brick veneer units are used with block back up, and when brick and architectural concrete products are used in the same Wythe bands of precast concrete or architectural concrete block in a brick veneer. afterwards their initial mixing or casting, mortar, poured-in-place concrete and concrete masonry units shrink as the curing of the Portland cement proceeds. This is an unavoidable consequence of the curing of concrete products and is accommodated in design.2.2.14 Sulphate Attack on BrickworkMost ordinary clay bricks contract sulphates of sodium, magnesium or calcium. These salts are soluble in water, calcium sulphate being less soluble than the other two. Normally, these sulphates are seen as the clear efflorescence which affect appearance only and need simply to be brushed away. In theory, most brick walls with mortars based on OPC (Ordinary Portland Cement) are reasonable to sulphate attack. The most vulnerable walls are earth-retaining walls and parapet walls but sulphate attack is a problem also on r endered, and facing brickwork.On rendered brickwork, sulphate attack is manifested by cracking of the rendering, the cracks being mainly horizontal and corresponding to the mortar joints below. The rendering may adhere quite well to the bricks early in the attack but areas are likely to grow detached as the expansion of the underlying brickwork causes severance of the bond between the two materials. (Eldridge, 1976)2.2.15 Lime Staining on BrickworkLime staining occurs when calcium hydroxide is deposited on the face of brickwork. Lime staining will rapidly absorb carbon dioxide from the air and vexs calcium carbonate. It is virtually insoluble and can only be removed by expert which is a pricey treatment. The calcium hydroxide can come from three main sourcescalcium hydroxide caused by the hydration of Portland cementfrom hydrated lime added to mortarfrom brickwork in contact with wet concrete2.2.16 Porosity on BrickPorosity is an important characteristic of bricks. In contrast t o other moulded or pre-cast building materials, the porosity of bricks is attributed to its fine capillaries. By virtue of the capillary effect, the rate of wet dribble in the brick is ten times faster than in other building materials. Moisture is released during day-time and re-absorbed during night-time. The ability to release and re-absorb moisture by capillary effect is one of the most useful properties of brick that helps to regulate the temperature and humidity of atmosphere in a building. This distinctive property makes bricks an admirable building material, particularly suitable for buildings in the tropics. On the other hand, all porous materials are tractable to chemical attacks and liable to contamination from weathering agents like rain, running water and begrime air.2.2.17 Crack in Brick Faces / FirecracksThe finished appearance of clay brick can quit greatly this is because it is dependent on clay and the manufacturing process. Some products contain cracks of varyi ng degree (sometimes referred to as firecracks) as an inherent feature. Firecracks are usually unmistakable on the product as delivered. However, firecracks can be masked by the texture and surface sands used in the manufacturing process which becomes visual after the bricks are laid as a result of inwrought weathering of exposed brickwork.2.2.18 Dampness of the Brick WallMore or less persistent dampness showing more clearly on the internal wall surface from ground level up to a height of approximately 750mm, but may be higher in severe cases or if the outer face is covered with a non-porous finish. The decorations may be damp, blistered or discoloured, or, if dry, may have been pushed off the wall by a pick out or salts which will often be seen as a sericeous crystalline growth. The possible causes of dampness in the brick wall are overlook of DPC (damp proof course), by-passing of the DPC, and failure of the DPC material.2.2.19 Brick Growth and Expansion Gaps in BrickworkB ricks undergo semi persistent permanent expansion over time. This expansion continues for the look of the brick, but the volume of the growth occurs early in its life. Most general purpose bricks have a coefficient of expansion in the range of 0.5-1.5mm/m (millimeters per meter) over 15 years. Designers can use the values of the coefficient of expansion to accommodate for the growth of bricks by the size and spacing of the control joints. The provision of control gaps or junction joints between parts of the structure during construction will accommodate movements within the structure over time. Numerous sources of movement exist and includeThe change in size of building materials with temperature, loading conditions and moisture contentThe differential gear change in size of building materials (for example, cement products shrink over time, whilst clay bricks expand slowly over time)Foundation and footings movement butt against movementFrame shorteningTemperature movementInterna l horizontal and vertical movement2.3 Causes of the brickwork defects2.3.1 IntroductionBrickworks are used primarily in the construction of walls. To construct the brick wall required many skills, design, subsist, selection of material, and technique. Lack of all expertise may cause the brickwork defects or failure of the building. The defects that occur in brickwork maybe the result of inherent faults, deficiencies in merchandise, design, materials or workmanship, and attack by surroundal agents.After the brickwork has been constructed, it maybe meets of various requirements, climate, loading, and occupational in use. It is not surprising that defects happened or occurs frequently.In this sub chapter, the causes of the brickwork defects will be list out. To find out the actual causes of the brickwork defects will be easily for the occupational to take the right remedies immediately and reduces the brickwork defects happen.2.3.2 Selection of bricksThe choice of bricks is often inf luenced by the price but the part required mustiness also be care amply considered in order to avoid defects developing during the service life of the material. Therefore, the selection of suitable bricks for any particular purpose has often to be a trade-off between appearance and durability requirements on the one hand, and cost on the other.This is not always possible to assess the quality of bricks by the colour, variability of colour of bricks of the same source and mode of production can often be an indication of military authority and durability variations.2.3.3 repositing of bricksBricks on site are rarely kept under adequate cover. Defects in the bricks resulting from the deprivation of adequate protection on the site are rarely apparent before use. However, bad weather conditions can be detrimental to bricks in that saturation by rain can be responsible for both subsequent efflorescence and decoration defects.2.3.4 Soluble Salts in BricksUnder burnt bricks contain a high salt content. The salts come from the raw clay from which the bricks are made, or are formed in the burning process. Most clay bricks contain some soluble salts, but the types and amounts vary appreciably. The effect of the soluble salts on both efflorescence and the more serious problem of disintegration of bricks themselves are largely governed by the lastingness and pores structure of the bricks.2.3.5 Sulphate attackSulphates are salts which are naturally rescue in industrial waste, gypsum product, clay bricks, flue condensates and in some ground waters. In persistently damp conditions, sulphate will react slowly with tricalcium aluminate forming a compound called calcium sulphoaluminate. This reaction causes the cement mortar or render of the brickwork to expend and eventually disintegrate.2.3.6 Solar RadiationWhile drying out of grease by directs is the most common reason for cracking in brickwork, some clay are also very susceptible to drying out by direct solar rad iotherapy. The northern facing wall is the most likely to be affected and stepped diagonal cracking is the most common symptom, usually occurring at the north east and north west corner of the building. (Loveder, 2000)2.3.7 Migration of moistureThe movement of moisture beneath a building can produce the phenomenon cognize as long term dome and mantrap effect. The dome effect is a slow heaving of the soil caused by movement of moisture from the perimeter of the house to its centre, and the saucer effect is moisture moving in the opposite direction, from the centre towards the perimeter. The dome effect causes the walls to rock n roll outwards and the restraining influence of the roof produces horizontal cracks on the outside wall. These will be wider on the outside surface rather than the inner.2.3.8 put of treeSome of the brickwork defects may cause by freehanded trees roots that works nearby the building area. When planning to plant trees, the idea to be considering is the a uthorization of the footings under the house. If lack of strength, the roots of the trees maybe grow into the ground under the building and cause the brick wall settlement and cracking.2.3.9 Uneven settlement of foundationsWhere a particular heavy load is placed on the foundation such as a large column, movement may occur as moisture is squeezed out of the soil or the soil readjusts itself. This consolidation will stop when the soil has finally compacted luxuriant to support the load. Brick wall or masonry wall may crack which may result from movement during compaction.2.3.10 uppity shakingDamage caused by vibration from earth tremors, heavy work or pile driving is fairly rare, however if the vibration is great enough to actually cause the foundation to move, brickwork cracking or defect can occur. The crack will show up irregularly if the sources of the vibration cannot be removed. (Loveder, 2000)2.3.11 Additional buildingBuilding an addition building onto a house or add more s torey of houses can confab a load intensity on the soil different that which is at that place already and so cause differential settlement. Even if the loading intensities are similar, the difference in time between when the two settlements occurred can be enough to create the brick wall cracks.2.3.12 Approach of designDesign of brick wall is very important. The designer must have the knowledge about the brick experience in chosen the types of brick to be used. The designer must be fully aware of the clients needs. Defects often occur because of a lack of understanding of the different types of bricks and the method of construct the brick wall.2.3.13 Lack experience of workerWorkers in the masonry construction is not in strict accordance with the construction and standards, masonry mortar is not full, especially in vertical mortar joints are not full, and even produce dense seam, seam permeability. In addition, the dry brick on the wall, mortar in the brick water was absorbed, cau sing low strength of mortar, brick and mortar separation, so that the overall stiffness of masonry fell, gray mortar joints crack.2.3.14 OverloadingCracks of brickwork may result from overloading of the ground on which the building rests, or of the building itself or parts of it. let go of the load does not necessary allow the masonry wall to revert to its original state since the overloading may have been partially accommodated by a permanent compaction of the bricks. The forces responsible for the overloading may be of external origin, such as excessive wind, or may be internal, such as those arising from the evocation of excessively heavy equipment for which the masonry wall was not designed. A change of occupational may have same results.2.3.15 Lack of alimentMaintenance must be taken for all the building to minimize the cost of repair work for seriously defects happen. Lack of maintenance will make a small cracks or defects on brickwork change to more serious and serious.2.3 .16 awry(p) soil depth psychology and preparationWhen a builder chooses an area of land to build on, it is important to do some sort of soil analysis and preparation. The analysis will provide the developer and/or builder with enough training to choose the adequate soil preparation and construction strategy that should be used to develop the land. Improper soil analysis and preparations can be very damaging to a housing development. For example, a builder can discover that the land soil is made up of expansive soil. If this is the case, houses need to have a foundation that will be able to support the changing pressure and consistency of the soil. This is because expansive soil will sheikh when wet and and then shrink once it dries. If one builds on this type of soil and is not aware of it, there will inevitably be issues to handle. There will be crack in the brick wall or masonry wall. The repair of this is very costly and very intrusive. Unfortunately, the reality is improper soil analysis and preparations happen all the time.2.3.17 Negligence of constructionNegligent construction is an unfortunately common occurrence. A builder has to be very thrifty when choosing a contractor or subcontractor. A builder will sometimes use one contactor for various projects. A contractor may have skills to install floor tiles but not the know how to build a brick wall. The responsibility can fall on several parties when there is a defect, and thats up to your attorney to determine.2.3.18 Movement of the groundMining subsidence, landslips, earthquakes, or moisture changes of shrinkable clay soil may cause the movement of the ground. The brick wall of the building will be crack because the wall of building has become displaced from the rest without any change in actual size of the materials. In theory, this is possible to reconnect the displace parts to bring the building back to its original condition but in practice this seldom can be done.2.3.19 Acid rainAcid rain is precipitation that is much more acidic than normal rainfall, and the acid rain is usually caused by contaminant such as sulfur and nitrogen emissions. Several different mechanisms are operant in the deterioration of brick masonry through the action of acid rain. The bricks are susceptible to acid rain through the selective dissolution of their vitrified phase. The mortar is affected mainly by the reaction of the calcareous components. The soluble salts resulting from these reactions, in solution with rain water or condensed moisture, will reincarnate through the porous matrix of the masonry. In the places where the water evaporates the salts will be deposited. Repeated dissolution and re-crystallization of these salts leads to the mechanical disruption of the masonry structure. Since the salts will concentrate in the more porous material, either the brick or the mortar will be more seriously affected, depending on their relative porosity.2.3.20 EnvironmentTwo aspects of the envir onment have been considerably which is wind and temperature. This is because they cause loading to be use to the structure. The strong wind may cause the brick wall or the completely building move, this may cause cracking to the part of the building. The high temperature applied to the brickwork may cause spalling and brick prolong to high temperature can lead to surface vitrification. (Swoden, 1990)Table 1 Causes of the brickwork defect and the preventive method to avoid it happenNo.Causes of brickwork defectsPreventive method1.Selection of bricksUse the bricks that are strength and durability2Storage of bricksKeep the bricks under dry place3.Soluble Salts in BricksUse the bricks that are less contain of soluble salts4.Sulphate attackEnsuring the wall does not get and stay in unduly wetted. Use cement low in tricalcium aluminate5.Solar radiationMake sure trees plant far away from the brick wall6.Migration of moistureUse of damp proof course below the brick wall7.Planting of treeMa ke sure there have no big tree nearby the brick wall8.Uneven settlement of foundationsMake sure the foundation is strong enough9.Excessive vibrationMake sure the foundation is strong enough10.Additional buildingDo not build additional building of brick wall after a long period finish of brick wall11.Approach of designDesigner must be experienced and knowledgeable12.Unskilled workerMake sure the brick wall is built by skilled worker13.OverloadingBrick wall must be design according to building use14.Lack of maintenanceMust me maintenance the brickwork annually15.Improper soil analysis and preparationCheck the soil properly and make sure the design of brick wall is strong enough16.Negligence of constructionCareful when choose the contractor17.Movement of the groundMake sure the foundation is strong enough18.Acid rainWash or clean the brickwork before it decay or surface treatment19.EnvironmentUse the brick that are strength and durability2.4 Remedies method of the brickwork defects in building2.4.1 IntroductionAs known early, brickwork is one of the largest parts of most of the building. The strength, stability, and durability of brickwork are very important. If lack of all those factor, the brick wall or masonry wall maybe fall down or collapse suddenly.If the brickwork occurs any cracking or defects, the right method of remedies must be taken immediately. This is to ensure that the occupational or owner use the building under safety and healthy purposes.Brickwork will deteriorate and decay if not properly maintained. Such deterioration can be caused by a number of factors and can take various forms. The main signs that brickwork is suffering are surface growth and staining, efflorescence, loosed brick becoming dislodged, crack appears thumb the bricks or mortar and etc. So, the right remedy must be taken to ensure the brickwork do not decay and deteriorate. (Moses Jenkins, 2007)In this sub chapter, the remedies method for various types of defects will be list out. This is to avoid the brickwork defect getting serious in building in construction industry. The defects of brickwork must be repair immediately, if not the defects will be more serious. For example, cracking can be due to expansion or shrinkage the clay brickwork itself.2.4.2 Remedies of efflorescenceEfflorescence can be minimized by place dry bricks and by speeding up the drying process after the bricks have been laid by providing good ventilation. The salts that cause efflorescence are soluble in water. Hosing with water will cause the salts to dissolve and be re-absorbed into the brickwork, and then reappear when the brick wall dries out again. Acid or alkaline treatments are not recommended as they increase the salt content of the wall. The best method is simply brush off the deposit with a stiff dry bristle brush after the wall has dried out. Then arse around the surface with a damp synthetic chamois or high suction wipe. Use very little water and rinse sponge frequentl y in fresh water.2.4.3 Sand-Blasted BricksWhich have been cleaned of old paint, algae, or stains using high pressure sand blasting or possibly even v