The universe is at the jaws of crisis in many sectors in the close hereafter. One of the most of import of them is the handiness of lumber. World is going more and more urbanised. There must be some kind of solution which can give some alleviation to the hungriness towards the demand of lumber. We need to look for a solution which must hold few features such as
A merchandise which can replace wood in the widest scope of intents of uses..
A merchandise which does n’t hold negative environmental impact or is eco-friendly..
A merchandise which can be made in a rural environment to help in cut downing the force per unit area of urbanisation in the current universe.
A merchandise whose production graduated table must be such that it should n’t displace the rural people from its range.
A merchandise which is really much meaningful in the activity.
Bamboo is decidedly one such solution we got for the close hereafter. Bamboo merchandises can replace wood-based merchandises in a really broad scope. The cultivation and care of bamboo is really easy in comparing with wood. Bamboo can be grown as bunchs in most dirts and is really inexpensive which makes it a executable stuff for hapless people and in rural parts. More and more people can be involved in this procedure to do them cognizant of the possibilities with bamboo. Bamboo based industries must be encouraged by maximal villager engagement as it even requires really low capital. Bamboo based industries can therefore supply the clip and infinite for evolutionary development of the rural economic system.
1.2 THE PROBLEMS
( 1 ) The universe produces 3.5 billion dozenss of wood from approximately 3.5 billion hectares of forest. Approximately half of that is used as firewood. In the developed universe, less than one billion people consume an norm of about 1 ton per capita per twelvemonth, barely any of it as firewood. The richer the state, the higher this sum ( in the USA it is 2.3 metric tons ) . Therefore, in the poorer parts of the universe, people consume far more firewood than industrial wood ( by a factor of at least three to one ) . The overall aim of universe development is that criterions of life should lift. At the present, China ‘s one-year per capita wood ingestion is merely 0.16 m3 – much lower than the planetary norm of 0.65 three-dimensional metres ( China Daily, 13 April 2000 ) . Will the underdeveloped universe start to devour wood in a mode similar to the developed universe as it becomes richer. The grounds is non clear but South Korea has seen a quadrupling of its per capita ingestion between 1950 and 1990. Although China ‘s per capita lumber ingestion remains much lower than the planetary norm, its demand for lumber has increased drastically over the last few old ages, while its supply has remained steady or decreased somewhat ( China Daily, 13 April 2000 ) . Will new engineering ( email and Internet ) cut down the sum of paper used? Again the grounds is non clear but at that place seems to be no strong tendency as yet. The effects for universe wood ingestion are hence really serious if rising criterions of populating lead to an accelerated use of wood merchandises [ 10 ] . If the universe population ( six billion now swerving towards eight billion in 25 old ages ‘ clip ) moved to devour wood in a form similar to the more developed states ( e.g. 1 M3 / capita in Germany [ 11 ] ) the ingestion of industrial wood ( excepting firewood ) would necessitate to at least quadruplicate ( as it did in South Korea ) . It is improbable that the wood presently consumed as firewood could help much, for well-known proficient grounds ( it is frequently dead wood, little sized and sparsely distributed ) .
( 2 ) The country of wood is being reduced by go oning deforestation. This is compounded by a turning consciousness that woods have values over and above their lumber value ( for C keeping – mature woods may non really sequester excess carbon-for biodiversity shelter and for dirt, H2O and air quality values ) . Thus the supply of timber-producing wood is diminishing, through saving, in such diverse economic systems as the USA, Australia, New Zealand, India and China.
( 3 ) In the last two centuries, bettering criterions of life have been preceded by big additions in population and increasing urbanisation. It is self-contradictory that the population appears to increase quickly before additions in life criterions appear and that steeply lifting population can endanger to call off out those additions. Developing states are following along the form foremost established in Britain 250 old ages ago but with some differences. The English population rose from 6 million in 1750 to 40 million in 1900 but would hold increased to over 60 million were it non for the immense outward migration to the US, Australia, New Zealand and South Africa. Even with that safety valve, little small towns like Birmingham increased from populations of merely 4000 in 1680 to 400 000
in 1881, as people left the countryside for the towns. They had small pick. There was non plenty free land in the countryside for farming. Populating conditions for most of the population in these metropoliss were really hapless and their on the job conditions dehumanized. Today ‘s developing states do non hold the possibilities of abroad migration ; they face the same force per unit areas towards urbanisation but do non wish to reinvent the ‘dark demonic Millss of the 18th and nineteenth century. It would be good if sufficient employment could be found in a rural environment to cut down the force per unit area towards urbanisation.
( 4 ) Studies in both the developed economic systems and the developing economic systems have come to the decision that people work best in little to medium size firms/enterprises where they can see the impact of their ain attempts and where they feel that they can hold an consequence on decision-making. These decisions find their look in the general construct of ‘participation ‘ .
-IAN R.HUNTER, 2002, “ Bamboo and Rattan ” , Vol. 1, No.2, pp.101-103, Available at: www.vsppub.com
It ‘s non like bamboo can be the lone solution for all these issues outlined above but experiences in few topographic points indicate that bamboo can do some meaningful part.
2.1Bamboo as a wood replacement
The bamboo culm, reduced to its finest parts, is an first-class industrial fibre. As such it has been shown, both in the research lab and in pattern, to be an first-class replacement for wood fibre in such things as paper, medium denseness fiber board and veneer. There are really few proficient troubles in using normal wood-working machinery to work with bamboo. One difference that does necessitate to be accommodated is the higher silica content of bamboo which can dull cutting borders. With good physical and mechanical belongingss, low shrinking and mean denseness of 0.7 g/cm3, bamboo is good suited to replace wood in several applications, particularly in panel signifier. Bamboo mat board and bamboo strip board have been exploited on an industrial graduated table, and merchandises marketed for assorted terminal uses such as flooring, roofing, and other lodging constituents, furniture, packing instances, etc.
At present, in China, over 1,000,000 M3s of panels of assorted types are produced yearly in some 200 Millss, whereas in India, industrial-scale production of panels is confined to bamboo mat board with about 2000 M3s board by seven Millss. The planetary usage of paper is reported to be increased by 5 % yearly. Today, Asia, and chiefly India and China, make the most usage of bamboo for mush and paper. India uses about 3 million dozenss of bamboo per twelvemonth in mush industry and China about 1 million dozenss, and both are set to increase their usage of bamboo for paper mush industry ( China targets 5 million dozenss per twelvemonth ) . Bamboo mush is besides processed into incense paper in the Philippines for export. Brazil is soon the lone American state that uses bamboo for doing cellulose and paper. However, bamboo has certain features that are superior. It has a high surface hardness such that laminated bamboo flooring is equal in wear to the hardest American hardwoods.
Many of the merchandises made from bamboo can be and are made in little mills with really limited capital demands ; hence these mills can be distributed around the country-side stopping point to their natural stuff.
Bamboo besides has a alone function to play in building strong light-weight houses. It has been known for a long clip that light weight lumber frame building houses offer the greatest safety against temblors and besides greater safety on earth faux pass. Lightweight lumber bordering lodging is the norm in New Zealand. In 1987, the little town of Edgecombe in the northern portion of the North Island of New Zealand was shattered by a force 7 temblor. The force of the temblor was sufficient to tip a railroad engine on its side. Yet no-one was killed and all of the houses remained standing. There are two engineerings using bamboo that can be adapted to supply similar sorts of houses. In one, bamboo poles can be used in a similar manner to timber he-mans to supply a similar space-frame building. Work needs to be done bettering the articulations before the consequence is every bit strong as a lumber 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 efficaciously reinforces the concrete daubing. This 2nd manner of edifice produces a consequence which is more culturally familiar in many states and perchance hence more acceptable.
2.2 Properties of Bamboo:
2.2.1 Tensile strength:
The bamboo fibres run axially. In the outer zone are extremely elastic vascular packages, which have a high tensile strength. The tensile strength of these fibres is higher than that of steel, but to build connects which can reassign burden axially is simply impossible.
Bamboos shrinks a batch more tan wood when it loses whole of its H2O. Nodes are really vulnerable during this shrinkage. Bamboo psychiatrists in the cross subdivision 10 to 15 %
2.2.3 Fire opposition:
The fire opposition is really good because of the high content of silicate acid. Filled up with H2O, it can stand a temperature of 400A° C while the H2O cooks inside.
Bamboo ‘s tremendous snap makes it a really good edifice stuff in temblor prone zones. Its is really light in weight and can be easy worked on.
-Bamboo as a edifice stuff, 2002, available @ www.bambus
2.3 Bamboo for building:
There is a significant function of bamboo in the building field as it grows of course, it has strength, flexibleness and versatility and is really suited stuff in every portion of a house when treated and is used decently. Not merely there are proficient advantages with bamboo but it is really economical as it is a local merchandise in many topographic points of the state and is amongst the cheapest stuffs available. Recently there are hikings in the monetary values of bamboo but with proper cultivation and increased production these rising pricess in the Fieldss of bamboo can be handled. Cultivating of bamboo properly gives high outputs. Furthermore bamboo can replace use of lumber in many countries. It can lend towards the solution for the deforestation which is a really major concern in the universe.
Bamboo herpes zosters whose lengths are about every bit long as balks. The bamboo canes are first halved along their stop and are bisected. Then they are threaded as alternate confronting units and are tied. They are held in the supports by their ain weight.
Fabrication of roof trusses is about the most promising usage of bamboos. Literally, any span of truss is possible, and every bit indicated in Section 5, a Fink truss of about 8.5m span can be carried by three workingmans and installed by about 5 workingmans. The belongings of lightweight with strength and stiffness is manifested here. Besides, significant nest eggs in the non-use of heavy lifting equipment.
( two ) Scaffolding
( three ) Catastrophe Extenuation
The elation of bamboo, broad handiness and possibility of constructing shelter from modular units lends it for usage for post-disaster shelter. A undertaking is in the offing by the UNHCR where impermanent shelters are fabricated from A-shaped bamboo support frames with horizontal members at the vertex and at mid-heights of the A-frame. A water-proof sheet is draped over this frame for screen.
Bridges attempted consist of:
( a ) Footbridges: Simple cross-braced frames with the paseo formed at the crutch.
Culms of 50-75mm diameter are bound by bamboo tonss. They are suited to rivers with muddy or sandy undersides where the tallness above bed does non transcend 5m. A typical crossing might be 20m long.
( B ) Handcart Bridge: The building is more luxuriant with abutments and piles. The abutments are formed from braces of culms staked to the land. A brace of horizontal culms forms the pile cap and diagonal braces stabilize the assembly. To organize the roadway, three longitudinal bamboo beams of 100mm O are lashed to the caps and tied together at the centre of each bay with a cross-member.
Bamboo can be used for the building of save stagings for really tall edifices because of the favourable relationship between supporting capacity and weight. Bamboo has been used for centuries as scaffolding in Asiatic states and, despite competition with many metal scaffolding systems, remains one of the most preferable system in both China and Hong Kong ( Fu, 1993 ) . Owing to its high adaptability and low building cost, it can be constructed to any layout to follow assorted irregular architectural characteristics of a edifice within a comparatively short period of clip ( Chung, et al. , 2003 ) . They are used in building sites to supply impermanent entree, working platforms for building workers and supervisory staff, and to forestall building dust from falling on passerby. In Hong Kong, they are used as Single Layered Bamboo Scaffolds ( SLBS ) for light work and Double Layered Bamboo Scaffords ( DLBS ) for heavy work ( Chung and Sin, 2002 ) .
Bamboo staging, like any other, must possess unity and must be laterally stable. The foregoing is ensured by the proviso of brace. The brace is by two pieces of bamboo fixed in an ‘X ‘ form and at an angle of 60o-70o over the subdivision of bamboo to be braced. For multi-storey constructions it is required to bind the staging to the edifice frequently through 6mm Defense Intelligence Agency mild steel bars ( putlogs ) pre-fixed to concrete at every floor. A prop is besides required between the edifice and the staging to forestall the propensity of the staging towards the edifice.
Even at their connexions the canes are non treated in any manner. Merely lashed articulations are used. The cane extension is carried out by floging the cane ends together with several ties. The ties are arranged in such a manner that forces moving vertically downwards wedges the nodes in the whipping. With larger cane diameters the clash can be increased by fastening the rope between the canes. The perpendicular and horizontal canes used for scaffolding are about entirely united utilizing soft whipping. This technique has the great advantage that the articulations can be tensioned to the right grade without trouble and besides rapidly released once more.
-Dunkelberg, Klaus: Bamboo as a edifice stuff, in: IL31 Bambus, Karl Kramer Verlag Stuttgart 1992.
3.1 Mechanical and Structural Properties
Bamboo, being a handbill, hollow construction has certain mechanical and structural advantages and disadvantages as compared to a rectangular solid lumber of the same cross-section. These advantages/disadvantages are, in other cases, complemented or accentuated by the cellulose fiber makeup of the bamboo. These comparative analyses are tabulated in Table 1.0. Some regulations of pollex for the relationship between the mass per volume of bamboo and some mechanical belongingss have been derived by INBAR and Janseen ( 1991 ) . These are given in Table 2.0. Besides, assorted trials for strength and mechanical belongingss and design regulations have been put frontward 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 )
of Inertia, I
aˆ? Fortimber, largely
aˆ? E fiber=
aˆ? 50 % of cross-
sectionof fiberis cellulose.
aˆ? Ea‰?350x % of fibres.
aˆ? Inbamboos, fiberis
60 % on outsideand
10 % on interior, hence
transversestraininfibers of topfaceof culm.Lignin infibresisweakinstrain. Coherenceincross-
sectionis lostandEI drops dramatically.
aˆ? Poissoncoefficient forbamboo= 0.3.
aˆ? Shearin neutrallayer=
aˆ? Smallerthicknesstoresist shear.
aˆ? Largerforcesonbolt fastenersatjoints.
aˆ? Advantageof nothavinga
aˆ? Hasrays.Raysare mechanicallyweak.
Hence, timbermaterial isweakerinshear
Table 1.0 ( Cont ‘d )
aˆ?Bendingstressdueto air current
aˆ?Attop ( nearskin ) vass
replacesvessels, taking toincreaseresistanceto bendingstress.
solidmassfromcenter, longitudinalshorteningis greaterandthusgreaterthe likelihoodof lateralstrainin lignin.
aˆ?Solidnaturemakesfor bettercompression resistanceandreduced lateralstrain.
Table 2.0: Rules of Thumb Factors for Mechanical Properties of Bamboo
Ultimatestress ( N/mm2 ) =Factor xmass/volume ( inkg/m3 )
Allowablestress a‰? 7 xUltimatestress
JANSSEN, J.J.A. , 2000. Planing and Building with Bamboo. INBAR Technical Report No.20, page no. 18-23
3.2 Earthquake Resistance
Bamboo, being lightweight and hollow, makes it of course extremely immune to temblor ( because it has high stiffness in relation to its weight ) . That, it does non shatter at failure means that when the temblor is over the edifice can be left standing with comparatively minor harm ; supplying shelter whiles the harm is being repaired. In a 7.5 magnitude temblor in April, 1961, in Costa Rica, 20 bamboo houses were left standing near the epicentre ( Janssen, 2000 ) .
4.1 Problems related to Bamboo.
The available bamboo tends non to be really directly, have variable diameters, culm thickness and show marked tapering. These properties have a dearly-won consequence on preliminary efforts at building in bamboo, as will be indicated subsequently.
4.1.2 Insect and Fungi Attack
More than anything else, the job with bamboo is pest and fungi onslaught. Insect onslaught is through the comparatively softer tissues in the interior wall of the pit wall and at the budding points in the nodes. Fungi onslaught is terrible when the bamboo is exposed to muffle conditions. Assorted methods exist for bar of these onslaughts ( Jayanetti and Follet, 1998 ) . They range from the sophisticated modified Boucherie procedure, through submergence in a boracic acid/borax mixture in H2O, injection and picture with creosote, to hanging in a streamlined watercourse instantly after reaping for at least a hebdomad for the sugary ingredients to be washed out.
Traditional saving methods besides exist such as hardening, smoke and lime-washing. The existent effects of such traditional methods are non known since they have non been documented and quantified.
4.1.3 Fire hazard
4.1.4 No standardization possible: no 2 culms are likewise
4.1.6Difficulty of doing the junctions of the culms
4.1.7 No building skills with bamboo culms in non-bamboo available states
4.2 Measures to be taken
4.2.1Treatment of the surface
This information about bleaching and dyeing are determined for little parts for kite-constructions. Bleaching and dyeing perchance can alter the construction of the bamboo that far, it canA?t support adequate weight. Nevertheless these methods should be introduced.
Bleaching in H peroxide removes hints of rosin or wax. If it stays in it excessively long, the bamboo will acquire perished.
Every state has developed its ain traditional method of dyeing.
1. Remove the wax, otherwise the colour canA?t penetrate into the bamboo.
2. Bleach before deceasing, so the colour will go more regular.
3. After dyeing, repair the colour in a solution of acetum.
4.2.4 Other methods:
In 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 colour. handling the canes with Cu sulphate will give a green colour to the bamboo and protects it from cast. These methods merely dye the surface of the bamboo. To acquire a through and through dyeing, the bamboo can be carbonized. The bamboo is put into a boiler and is incubated with a force per unit area of 5 kg/cmA? and a temperature of 150A° 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 Institute ( BRRI ) , page no 5-7