Bamboo as a construcyion material

BAMBOO

CONTENT

INTRODUCTION

AS A CONSTRUCTION MATERIAL

PHYSICAL PROPERTIES

CHEMICAL PROPERTIES

USES

JOINARY

CONCLUSON

INTRODUCTION• Bamboo are the largest members of the grass family.

• Bamboos are some of the fastest-growing plants in the world.

• Bamboo has a higher compressive strength than wood, brick or concrete and

a tensile strength that rivals steel.

• Bamboo used for construction purposes must be harvested when the culms

reach their greatest strength.

• In bamboos, the inter nodal regions of the stem are hollow and the vascular

bundles in the cross section are scattered throughout the stem instead of in a

cylindrical arrangement.

• Bamboo, like true wood, is a natural composite material with a high

strength-to-weight ratio useful for structures.

• In its natural form, bamboo as a construction material is traditionally

associated with the cultures of India, bamboo was used to hold up simple

suspension bridges, either by making cables of split bamboo or twisting whole

culms of sufficiently pliable bamboo together.

• In Japanese architecture, bamboo is used primarily as a supplemental and/or

decorative element in buildings such as fencing, fountains, grates and gutters,

largely due to the ready abundance of quality timber.

SUSTAINABILITY OF BAMBOO

• Rapid growth and regeneration

Bamboo is a grass. It is the fastest growing woody plant on earth. When bamboo are cut for building or other use,

the underground system of roots and rhizomes of the bamboo remains intact and the plant quickly sends up new

shoots which become culms. The term culm refers to the vertical “trunk” of a bamboo. A cut and trimmed culm is

called a pole.

Conventional

Hardwood forests take many more years to re-grow than bamboo. Bamboo inherently has the potential to be a very

sustainable alternative to hardwoods for the construction needs of the population. As the world population rapidly

expands, placing great pressure on hardwood resources, bamboo represents a significant alternative for reducing

this pressure and often a superior one depending on the use.

A renewable alternative resource for environmentally sustainable development

• Bamboo has better tensile and compression strength than steel, is harder than Red Oak and Maple, and has a

greater resistance to expansion and contraction associated with temperature and humidity changes.

Reduction of environmental toxins.

Bamboo consumes carbon dioxide at rapid rates while growing. Carbon dioxide is the prime contributor to global

warming. Bamboo cultivation does not require the use of pesticides, and fertilizers used are often organic. The typical

tree used in standard wooden fencing can take over 30 years or more to re-grow, with a harvesting cycle that

produces less oxygen, consumes less carbon dioxide, and produces more run-off than bamboo.

• High strength to weight ratio and its flexibility.

• It is particularly appealing, in seismic areas, as complement to relatively non rigid wall systems

such as straw-bale.

• Extremely strong fiber - twice the compressive strength of concrete.

- roughly same strength to weight ratio of steel in tension.

• Uses - in residential and commercial building applications

• Wall systems

• Floor systems

• Finishes

WHY BAMBOO USED FOR STRUCTURAL APPLICATIONS?

BAMBOO AS CONSTRUCTION MATERIAL

• Through research it has been found that some species of bamboo have ultimatetensile strength same as that of mild steel at yield point and this coupled with othermerits, boosts the usage of bamboo as construction material.

• Bamboo is a versatile material because of its high strength-to-weight ratio, easyworkability and availability.

• Bamboo needs to be chemically treated due to their low natural durability.

• It can be used in different ways for roof structure as purlins, rafters and reapers,for flooring, doors and windows, walling, ceiling, man-hole covers etc.

BAMBOO TRUSSES:

The bamboo has strength comparable to that of teak and sal. An experiment withthe construction and testing of a 4m span truss made of round bamboo and differentjointing techniques for web-chord connections gave results that were matchingwith the strength of timber.

BAMBOO ROOFS SKELETON

It consists of bamboo truss or rafters over which solid bamboo purlins are laid andlashed to the rafter by means of G.I.wire. A mesh of halved bamboo is made and islashed to the purlins to cover the roof.

BAMBOO WALLING/CEILINGAs the bamboo material is light in weight it is more advantageous in

earthquake prone areas as its chances of falling are very less and even if itfalls it can be re-erected easily with less human and property loss with leastefforts and minimum cost. Bamboo walls can be constructed in differentmodes like• Whole stem, halved or strips of bamboo can nailed to one or both the sides of the bamboo frame

• Split bamboo mats can be fastened to the bamboo posts or mats can be woven, mud can also beapplied to both sides of such mats

• Bamboo strips nailed to bamboo frame or posts for interior walling

• Cement or lime plastering can be done on the mud covering for better appearance and hygiene.

• It has been found that the bamboo in the vertical position is more durable than in horizontaldirection.

BAMBOO DOORS AND WINDOWS

Bamboo frames can replace timber frames appropriate to function. Bamboo mat

shutters fixed to bamboo frame or a panel of bamboo board fixed to the frame

which is hinged to the wall can be used as door. Small framed openings hinged

to the top in the wall can serve as windows.

BAMBOO FLOORING

Bamboo can be used as flooring material due to its better wear and tear

resistance and its resilience properties. Whole culms act as frame work and the

floor covering is done using split bamboo, bamboo boards, mats etc by means of

wire lashing these to the frame

REED BOARDSReed boards are made by flat pressing the reed at high temperatures.

These reed boards are used in elements like flooring, walls, ceilingand roofing. They can also be used for partitions, doors, windows etc.

SCAFFOLDINGBamboo poles lashed together have been used as scaffolding in high

rise structures due to their strength and resilience. The timber plankscan be replaced with bamboo culms and these can be lashed to thevertical culms.

@ The moisture content of bamboo varies vertically from the bottom to the top portions and horizontally from the outer layer to the inner layers.

@ Bamboo possesses very high moisture content.

@ Green bamboo may have 100% percent moisture. The fiber saturation point of bamboo is around 20-22 percent.

PHYSICAL PROPERTIES

@ Unlike wood, bamboo has no secondary growth; all gains after it reaches its full height are due to the addition of material to cells after the first year.

@ Wettability is the ability of a liquid to form a coherent film on a surface, owing to the dominance of molecular attraction between the liquid and the surface over the cohesive force of the liquid itself.

@ Fibers in bamboos are grouped in bundles and sheaths around the vessels.

@ Fiber length and fiber width varies within one internode

@ The percentage of fibers increases from the bottom to the top of the culm

@ The chemical composition of bamboo is similar to that of wood

@ The main constituents of bamboo culms are cellulose, hemi-cellulose and lignin, which amount to over 90% of the total mass.

@ The minor constituents of bamboo are resins, tannins, waxes and inorganic salts

CHEMICAL PROPERTIES

@ Bamboo contains other organic composition in addition to cellulose and lignin.

@ It contains about 2-6% starch, 2% deoxidized saccharide, 2-4% fat, and 0.8-6% protein.

@ The carbohydrate content of bamboo plays an important role in its durability and service Life.

@ The ash content of bamboo is made up of inorganic minerals, primarily silica, calcium, and potassium

@ Higher ash content in some bamboo species can adversely affect the processing machinery

TYPES OF JOINTS

:: DOUBLE BUTT BENT JOINT

::FRICTION TIGHT ROPE CONNECTION

::PLUG IN/BOLT CONNECTION

::POSITIVE FITTING CONNECTION

::INTERLOCKING CONNECTIONS

BAMBOO JOINARIES

PROCESSING OF BAMBOO AND TREATMENT OF BAMBOO:

::It has been found that bamboo panel composites have great potential, better

strength, dimensional stability and other characteristics.

::Main characteristic features, which make bamboo as a potential building

material, are its high tensile strength very good weight to strength ratio.

::It can be easily worked upon by simple tools and machines.

::The strength-weight ratio of bamboo also supports its use as a highly resilient material

against forces created by high velocity winds and earthquakes.

::Above all bamboo is renewable raw material resource from agro-forestry and if properly

treated and industrially processed, components made by bamboo can have a reasonable life

of 30 to 40 years.

::Though natural durability of bamboo varies according to species and the types of

treatments, varied uses and applications in building construction have established bamboo as

an environment-friendly, energy-efficient and cost-effective construction material

BAMBOO GATEWAY

BAMBOO HUT

PACIFIC RARE BAMBOO

BAMBOO HOUSE BOAT

BAMBOO RAINWATER GUTTER

BAMBOO BENDING

BAMBOO CHURCH

BAMBOO SCHOOL

BAMBOO FOREST HOUSE

BAMBOO SHUTTER

BAMBOO ROOFING

BAMBOO FLOORING

CONCLUSION

Scientific studies have shown that Bamboo can satisfy the various structural

requirements and also due to its technical performance, Bamboo can be used as

a construction material for various structural components.

The important advantages which make Bamboo a more suitable material are:

• It is economical and helps achieve cost effective construction.

• Bamboo is a fast growing species and it is a renewable resource which can

be cultivated in most types of soil

• The designs of the components being simple, there is no need of highly

skilled labor.

• The dependency on the natural forests for wood will be reduced, thus contributing to

the protection of the environment.

• As it can grow in many types of soil, bamboo cultivation is suitable for rehabilitation of

degraded forests and other waste lands thus converting them into fertile lands to some

extent.

• Creation of employment opportunities especially for the rural people as the Bamboo

mats have to be manually woven before making them into Bamboo Mat Boards,

Bamboo Mat Veneer Composites and Bamboo Mat Corrugated Sheets.

• Thus due to all the above aspects there will be overall welfare of the society,

particularly of the economically weaker section.

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BY…

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