The Bamboo And Construction With Bamboo Biology Essay

The Bamboo And Construction With Bamboo Biology seekThe domain of a function is at the jaws of crisis in some sectors in the darling future. unity of the most(prenominal) important of them is the availability of timber. World is becoming a cracking deal and much urbanized. There mustiness be almost sort of solution which lot give some relief to the hunger towards the need of timber. We need to confront for a solution which must nurture few characteristics much(prenominal) asA growth which basis substitute forest in the widest persist of purposes of procedures..A product which doesnt support negative purlieual impact or is eco-fri turn backly..A product which buns be made in a country-bred environment to assist in reducing the pressure of urbanisation in the current cosmea.A product whose production scale must be such that it shouldnt displace the rural people from its reach.A product which is actu solelyy much important in the activity.Bamboo is definite ly one such solution we got for the near future. Bamboo products back end substitute timberland-based products in a truly wide range. The cultivation and maintenance of bamboo is real easy in analogy with wood. Bamboo fundament be grown as clumps in most soils and is truly cheaper which makes it a feasible material for poor people and in rural regions. more than and more people can be involved in this process to make them aw be of the possibilities with bamboo. Bamboo based industries must be encourage by maximum villager involvement as it even requires very execrable capital. Bamboo based industries can therefore countenance the measure and space for evolutionary development of the rural economy.1.2 THE PROBLEMS(1) The world produces 3.5 billion tons of wood from around 3.5 billion hect atomic number 18s of forest. Approximately half of that is utilize as firewood. In the high-pitchedly-developed world, less than one billion people submit an medium of near 1 ton per capita per year, hardly any of it as firewood. The richer the country, the higher this union (in the USA it is 2.3 tonnes). Thus, in the poorer parts of the world, people consume far more firewood than industrial wood (by a factor of at least deuce-ace to one). The everyplaceall objective of world development is that standards of living should rise. At the present, Chinas yearbook per capita wood consumption is solely 0.16 m3 much lower than the global fair of 0.65 cubic meters (China Daily, 13 April 2000). Will the developing world start to consume wood in a manner quasi(prenominal) to the developed world as it becomes richer. The evidence is non clear except S go forthh Korea has seen a quadrupling of its per capita consumption between 1950 and 1990. Although Chinas per capita lumber consumption remains much lower than the global average, its demand for lumber has maturationd drastically over the last few long time, bandage its lend has remained steady or change magnitude s demoralisely (China Daily, 13 April 2000). Will new technology (email and Internet) reduce the add of paper used? Again the evidence is not clear entirely there seems to be no strong trend as yet. The consequences for world wood consumption argon therefore very serious if emanation standards of living lead to an accelerated practice of wood products 10. If the world nation (six billion now trending towards eight billion in 25 years time) moved to consume wood in a pattern similar to the more developed countries (e.g. 1 m3 / capita in Germany 11) the consumption of industrial wood (excluding firewood) would need to at least quadruple (as it did in South Korea). It is improbable that the wood currently consumed as firewood could assist much, for well-known technical reasons (it is often dead wood, down(p) sized and sparsely distri anded).(2) The ara of forest is world reduced by continuing deforestation. This is compounded by a maturement consciousness that f orests have note values over and above their timber value (for carbon retention mature forests may not actually unsay extra carbon-for biodiversity shelter and for soil, water and air quality values). Thus the supply of timber-producing forest is decreasing, done preservation, in such diverse economies as the USA, Australia, virgin Zealand, India and China.(3) In the last two centuries, improving standards of living have been preceded by large increases in population and increasing urbanization. It is paradoxical that the population appears to increase rapidly before gains in living standards appear and that steeply revolt population can threaten to cancel out those gains. Developing countries are following along the pattern introductory established in Britain 250 years ago simply with some departures. The English population rose from 6 cardinal in 1750 to 40 million in 1900 but would have change magnitude to over 60 million were it not for the huge external migration to the US, Australia, raw(a) Zealand and South Africa. Even with that safety valve, small villages the like Birmingham change magnitude from populations of only 4000 in 1680 to 400 000in 1881, as people left the countryside for the towns. They had little choice. There was not enough free land in the countryside for farming. Living conditions for most of the population in these cities were very poor and their running(a) conditions dehumanized. Todays developing countries do not have the possibilities of overseas migration they face the identical pressures towards urbanization but do not wish to reinvent the phantom satanic mills of the 18th and 19th century. It would be good if adequate employment could be found in a rural environment to reduce the pressure towards urbanization.(4) Studies in both the developed economies and the developing economies have come to the conclusion that people work best in small to medium size firms/enterprises where they can see the impact of their own efforts and where they incur that they can have an effect on decision-making. These conclusions find their expression in the general concept of participation.-IAN R.HUNTER, 2002, Bamboo and Rattan, Vol. 1, No.2, pp.101-103, Available at www.vsppub.comIts not like bamboo can be the only solution for all these issues outlined above but experiences in few places indicate that bamboo can make some meaningful contribution.2.1Bamboo as a wood substituteThe bamboo culm, reduced to its finest parts, is an excellent industrial vulcanized fiber. As such it has been shown, both in the laboratory and in practice, to be an excellent substitute for wood fiber in such things as paper, medium density fiber board and veneer. There are very few technical difficulties in utilizing normal wood-working machinery to work with bamboo. One difference that does need to be accommodated is the higher silica content of bamboo which can muted cutting edges. With good physical and mechanized properties, l ow shrinkage and average density of 0.7 g/cm3, bamboo is well suited to replace wood in several applications, especially in panel form. Bamboo mat board and bamboo airstrip board have been exploited on an industrial scale, and products marketed for various end uses such as flooring, roofing, and other ho use components, furniture, packing cases, etc.At present, in China, over 1,000,000 m3 of panels of various types are produced annually in some 200 mills, whereas in India, industrial-scale production of panels is confined to bamboo mat board with somewhat 2000 m3 board by seven mills. The global use of paper is inform to be increased by 5% annually. Today, Asia, and mainly India and China, make the most use of bamboo for frame and paper. India uses about 3 million tons of bamboo per year in pulp manufacture and China about 1 million tons, and both are set to increase their use of bamboo for paper pulp manufacture (China targets 5 million tons per year). Bamboo pulp is also aff ect into incense paper in the Philippines for export. Brazil is presently the only American country that uses bamboo for making cellulose and paper. However, bamboo has certain characteristics that are superior. It has a high step to the fore hardness such that laminated bamboo flooring is equal in wear to the hardest American hardwoods.Many of the products made from bamboo can be and are made in small factories with very limited capital requirements hence these factories can be distributed around the country-side close to their raw material.Bamboo also has a unique map to play in constructing strong light-weight houses. It has been known for a long time that light weight timber frame mental synthesis houses offer the greatest safety against temblors and also greater safety on earth slips. light timber framing housing is the norm in New Zealand. In 1987, the small town of Edgecombe in the northern part of the North Island of New Zealand was shattered by force 7 earthquakes. The force of the earthquake was fitted to tip a railway engine on its side. Yet no-one was killed and all of the houses remained standing. There are two technologies utilizing bamboo that can be adapted to provide similar kinds of houses. In one, bamboo poles can be used in a similar way to timber studs to provide a similar space-frame construction. croak needs to be done improving the joins before the result is as strong as a timber frame house. In the other, a bamboo frame or hurdle can be woven out of split bamboo and plastered on either side. The bamboo hurdle effectively reinforces the concrete plastering. This second style of structure produces a result which is more culturally familiar in many countries and possibly therefore more acceptable.2.2 Properties of Bamboo2.2.1 ductile intensity levelThe bamboo fibers run axially. outer zone constitute of exceedingly expansile vascular bundles, which have a high tensile strength. The tensile strength of these fibers is higher th an that of steel, but to construct connects which can transfer load axially is merely impossible.2.2.2 ShrinkingBamboos shrinks a lot more tan wood when it loses whole of its water. Nodes are very vulnerable during this shrinking. Bamboo shrinks in the cross division 10 to 15%2.2.3 Fire oppositenessDue to the presence of the high content of silicate acid it offers a very good resistance towards fire.. change up with water, it can stand a temperature of 400 C while the water cooks inside.2.2.4 ElasticityBamboos enormous elasticity makes it a very good construct material in earthquake prone zones. Its is very light in weight and can be easily worked on.-Bamboo as a building material, 2002, available www.bambusnewengreportsbuildingmaterialbuildingmaterial.html2.3 Bamboo for constructionThere is a unanimous employment of bamboo in the construction field as it grows naturally, it has strength, flexibility and versatility and is very commensurate material in every part of a house when tempered and is used properly. Not only there are technical advantages with bamboo but it is very economical as it is a local product in many places of the country and is amongst the cheapest materials available. Recently there are hikes in the prices of bamboo but with proper cultivation and increased production these inflations in the fields of bamboo can be handled. Cultivating of bamboo properly gives high yields. Moreover bamboo can replace usage of timber in many areas. It can contribute towards the solution for the deforestation which is a very major concern in the world.2.3.1 RoofingBamboo shingle whose lengths are almost as long as rafters. The bamboo canes are first halved along their diaphragms and are bisected. Then they are threaded as selection facing units and are tied. They are held in the supports by their own weight.2.3.2 Trusses forum of roof stick toes is about the most promising use of bamboos. Literally, any thwart of truss is possible, and as indicate d in Section 5, a Fink truss of about 8.5m span can be carried by three workmen and installed by about 5 workmen. The property of lightweight with strength and stiffness is manifested here. Also, substantial savings in the non-use of heavy lifting equipment.(ii) Scaffolding(iii) Disaster MitigationThe brightness level of bamboo, wide availability and possibility of building shelter from modular units lends it for use for post-disaster shelter. A project is in the offing by the UNHCR where unstable shelters are fabricated from A-shaped bamboo support frames with horizontal members at the apex and at mid- superlatives of the A-frame. A water-proof sheet is draped over this frame for cover.2.3.3 BridgesBridges try consist of(a) Footbridges Simple cross-braced frames with the walkway formed at the crutch.Culms of 50-75mm diameter are bound by bamboo flogs. They are suited to rivers with muddy or arenaceous bottoms where the height above bed does not exceed 5m. A common crossing migh t be 20m long.(b) Handcart Bridge The construction is more elaborate with abutments and pilings. The abutments are formed from pairs of culms staked to the ground. A pair of horizontal culms forms the obturate cap and diagonal braces stabilize the assembly. To form the roadway, three longitudinal bamboo beams of 100mm are lashed to the caps and tied together at the center of each speak with a cross-member.22.3.4 ScaffoldingsBamboo can be used for the construction of safe scaffoldings for very tall buildings because of the favorable relationship between the load-bearing capacity and weight. Bamboo has been used for centuries as scaffolding in Asian countries and, despite competition with many metal scaffolding musical arrangements, remains one of the most preferred system in both China and Hong Kong (Fu, 1993). Owing to its high adaptability and low construction cost, it can be constructed to any layout to follow various irregular architectural features of a building within a com paratively short power point of time (Chung, et al., 2003). They are used in construction sites to provide temporary access, working platforms for construction workers and supervisory staff, and to resist construction debris from locomote on passers-by. In Hong Kong, they are used as Single mould Bamboo Scaffolds (SLBS) for light work and Double Layered Bamboo Scaffords (DLBS) for heavy work (Chung and Sin, 2002).Bamboo scaffolding, like any other, must possess integrity and must be laterally stable. The foregoing is ensured by the provision of bracing. The bracing is by two pieces of bamboo located in an X shape and at an angle of 60o-70o over the surgical incision of bamboo to be braced. For multi-storey structures it is required to tie the scaffolding to the building often through 6mm dia mild steel bars (putlogs) pre-fixed to concrete at every floor. A prop is also required between the building and the scaffolding to prevent the leaning of the scaffolding towards the buildi ng.The canes are not treated even at their connections and only lashed joints are used. The cane extension is carried out by lashing the cane ends together by using several ties. The ties are lay in such that force acting vertically downwards wedges the nodes in the lashing. By tightening the ropes between the canes the friction can be increased to the maximum. The vertical and horizontal canes used for scaffolding are joined using soft lashing. This technique has a great advantage that the joints can be tensioned to the right degree without difficulty and even released quickly.-Dunkelberg, Klaus Bamboo as a building material, in IL31 Bambus, Karl Krmer Verlag Stuttgart 1992.3.1 machinelike and Structural PropertiesBamboo, being a circular, travail structure has certain mechanical and structural advantages and disadvantages as compared to a orthogonal solid timber of the same cross- percentage. These advantages/disadvantages are, in other instances, complemented or accentuated by the cellulose fiber make-up of the bamboo. These comparative analyses are tabulated in put off 1.0. about rules of thumb for the relationship between the push-down store per volume of bamboo and some mechanical properties have been derived by INBAR and Janseen (1991). These are given in Table 2.0. Also, various tests for strength and mechanical properties and design rules have been put forward by INBAR (ISO-22156, 22157, ISO/DTR-23157.2).Comparative Mechanical Properties of Bamboo and Rectangular Lumber (Janssen, 2001)Table 1.0 Comparative Mechanical Properties of Bamboo and Rectangular Lumber (Janssen, 2001)PropertyBambooRectangular LumberAssumptions1.Momentof Inertia, II = 0.40A2I = 0.16A2 For most bamboos,d = internal diameter= 0.82D For timber, broadlyh = 2 x b2.OptimumMaterialUse, EI4900A22240A2 Cellulose =70,000N/mm2 E fiber =35,000N/mm2 50% of cross-section of fiber is cellulose. E350x% of fibers. In bamboos, fiber is60% on outside and10% on inside, henceE outside = 3506 0 =21,000N/mm2 andE inside = 35010 =3500N/mm2 Edahoma =14,000N/mm2Bending Compression stress during fold may result intransverse strain in fibers of transgress face of culm. Lignin in fibres is weak in strain. Coherence in cross-section is lost and EI drops dramatically. If load removed culmreturns to original straightform. Timber lead not regainoriginal length whenload is removed. Poisson coefficient for bamboo = 0.3.4. cut back Shear in neutral layer =1.3x shear for timber Smaller ponderousness to resist shear. bigger forces on bolt fasteners at joints. Advantage of not having aray structure is nullified byhollow nature. Larger thickness toresist shear. Has rays. Rays are mechanically weak.Hence, timber material is weaker in shearthan bamboo material.5.Torsion Better torsional resistancedue to circular shape. Poorer torsionalresistance because ofsharp corners.Table 1.0 (Contd)PropertyBambooRectangular LumberAssumptions6.Wind subway Bending stress due to windis constant over hei ght ofculm. At top (near skin) vesselsdecrease and cellulosereplaces vessels, leading to increase resistance to refraction stress.7.8.CompressionDensity Because of hollow natureand thus greater duration ofsolid mass from center, longitudinal shortening is greater and thus greater the likelihood of lateral strain in lignin. Friction due to clamping attop and bottom of culmreduces lateral strain. Amount of lignin deter-mines compressivestrength not cellulose.700 800kg/m3 secure nature makes for better compression resistance and reduced lateral strain.850kg/m3Table 2.0 Rules of Thumb Factors for Mechanical Properties of BambooAir-dry bambooBendingCompressionShearE0.140.0940.02124Green bamboo0.110.075Ultimate stress (N/mm2) = Factor x mass/volume (in kg/m3)1Allowable stress 7 x Ultimate stressJANSSEN, J.J.A., 2000. Designing and Building with Bamboo. INBAR Technical Report No.20, scallywag no. 18-233.2 Earthquake ResistanceBamboo, being lightweight and hollow, makes it naturally h ighly resistant to earthquake (because it has high stiffness in relation to its weight). That, it does not shatter at failure means that when the earthquake is over the building can be left standing with relatively minor wrongfulness providing shelter whiles the damage is being repaired. In a 7.5 magnitude earthquake in April, 1961, in Costa Rica, 20 bamboo houses were left standing near the epicenter (Janssen, 2000).4.1 Problems related to Bamboo.4.1.1 StructureThe available bamboo tends not to be very straight, have variable diameters, culm thickness and show marked tapering. These attributes have a costly effect on preliminary attempts at construction in bamboo, as leave behind be indicated later.4.1.2 Insect and Fungi AttackMore than anything else, the problem with bamboo is pest and fungi attack. Insect attack is through the relatively softer tissues in the inside wall of the cavity wall and at the develop points in the nodes. Fungi attack is severe when the bamboo is expose d to damp conditions. discordant methods exist for prevention of these attacks (Jayanetti and Follet, 1998). They range from the sophisticated modified Boucherie process, through denseness in a boric acid/borax mixture in water, snap and painting with creosote, to hanging in a flowing stream today after harvesting for at least a week for the honeylike ingredients to be washed out.Traditional preservation methods also exist such as curing, smoking and lime-washing. The real effects of such traditional methods are not known since they have not been documented and quantified.4.1.3 Fire adventure4.1.4 No standardisation possible no 2 culms are similar4.1.5Maintenance4.1.6Difficulty of making the junctions of the culms4.1.7 No construction skills with bamboo culms in non-bamboo available countries4.2 Measures to be interpreted4.2.1Treatment of the surfaceFor small parts this information about bleaching and illusion are determined for kite-constructions. though it cant support en ough weight. Bleaching and dyeing possibly can change the structure of the bamboo that far, nevertheless these methods should be introduced.4.2.2 BleachingFor removing traces of resin or wax bleaching in hydrogen peroxide can be done. The bamboo provide get perished if it stays long.4.2.3 DyeingThere are diametrical traditional styles of bleaching in different countries.In principle1. The color cant penetrate into the bamboo if at all the wax is removed.2. The color will become more regular if it is bleached before dying.3. Fix the color in a solution of vinegar after dying.4.2.4 Other methodsIn Japan, the surface will be peeled off, hydrochloride acid is put on the bamboo and the canes are put in an oven. The canes get a brown color. treating the canes with bulls eye sulfate will give a green color to the bamboo and protects it from mold. These methods only dye the surface of the bamboo. To get a through and through dyeing, the bamboo can be carbonized. The bamboo is put into a boiler and is incubated with a pressure of 5 kg/cm and a temperature of 150 C for 20-30 min. After that, the bamboo will be brown through and through.-K. A. Solomon-Ayeh,USE OF BAMBOO FOR BUILDINGS, Building and Road Research build (BRRI), page no 5-7