Slide 1

Presented by:Adnan irshadKirti pandeyMd. Nasir IftekharNikhat Mustafa

BAMBOO AS A REINFORCEMENTPresented to:

Ar. Tauhid mehtabAr. Kashif rafi BAMBOO AS REINFORCEMENT

INTRODUCTION2

Bamboo has been used as a construction material in certain area for centuries. A study of bamboo is used as a reinforcement in precast concrete elements was carried out in U.S Army Engineer Waterway experiment station in 1964. Bamboo was given recent consideration for use as reinforcement in soil cement pavement slabs in which the slabs behave in elastically even under light loads.

BAMBOO AS A REINFORCEMENT

Cellulose fibers which run the length of the culms carrying nutrients between the leaves and roots.What gives bamboo its super-strength?lighter-colored lignin.

Bamboo has been compared to reinforced concrete:

Cellulose fibers Steel bars Lignin Concrete Combined strength of fiber & lignin is greater than sum of the parts.

WHY BAMBOO AS REINFORCEMENT

BAMBOO AS A REINFORCEMENT

BAMBOO CHARACTERISTICS4

Bamboo is giant grass not a tree.

The density of fibers in cross-section of a bamboo shell varies with thickness as well as height.

The strength of bamboo is greater than most of the timber products.

Bamboo is more prone to insect attack than other trees and grasses.

Bamboo can prevent pollution.

BAMBOO AS A REINFORCEMENT

CHARACTERISTICSBAMBOOSTEELTensile strength1000-4000kg/cm22300kg/cm2Comp. strength250-1000kg/cm21900kg/cm2Modulus of elasticity0.3x 106kg/cm22.1x106kg/cm2

properties

Properties differ with species, age, climatic factors, moisture content, and different heights of the Culm.

BAMBOO AS A REINFORCEMENT

COMPARISON OF BAMBOO AND STEEL6

The strength of bamboo is greater than steel.Bamboo is easily accessible.

Bamboo lowers the cost of construction.

Increases the strength of the buildings .

Bamboo can crack and deflect more than steel reinforcement.

Elasticity of bamboo is better than wood for seismic resistant housing.

BAMBOO AS A REINFORCEMENT

MECHANICAL PROPERTYSYMBOLVALUE (PSI)Ultimate compressive strength8,000Allowable compressive stresss4,000Ultimate tensile strength18,000Allowable tensile stresss4,000Allowable bond stressu50Modulus of elasticityE0.3x106

U. S. NAVAL CIVIL ENGINEERING LABAORATORY Port Hueneme, California By Francis E. Brink and Paul J. Rush

MECHANICAL PROPERTIES OF BAMBOO REINFORCEMENTS

BAMBOO AS A REINFORCEMENT

Bamboo as a raw material is non-forest product available in plenty. It is fast growing renewable resource .

Bamboo has good physical and mechanical properties.

Bamboo is unique in that it is strong in both tension and compression.

BAMBOO AS A REINFORCEMENTFEATURES OF BAMBOOTensile strength, compressive strength, modules of elasticity is far more greater than in any wood.

It is durable (for 30 years) and weather resistant.

Light weight, modular and interchangeable.

Good thermal and acoustical properties.

The following factors should be considered in the selection of bamboo culms (whole plants) for use as reinforcement in concrete structures: Use only bamboo showing a pronounced brown color. This will insure that the plant is at least three years old. Select the longest large diameter culms available.Do not use whole culms of green, unseasoned bamboo. Avoid bamboo cut in spring or early summer. These culms are generally weaker due to increased fiber moisture content.

SELECTION AND PREPARATION OF BAMBOO

BAMBOO AS A REINFORCEMENT

Bamboo can be permanently bent if heat is applied while applying pressure. This procedure can be used for forming splints into C-shaped stirrups and for putting hooks on reinforcement for additional anchorage. When seasoned bamboo, either split or whole, is used as reinforcement, it should receive a waterproof coating to reduce swelling when in contact with concrete. Without some type of coating, bamboo will swell before the concrete has developed sufficient strength to prevent cracking and the member may be damaged,

WATERPROOF COATINGS

Bending

BAMBOO AS A REINFORCEMENT

SELECTION AND PREPARATION OF BAMBOO

SELECTION

Use only bamboo showing a pronounced brown color. This will insure that the plant is at least three years old.

Select the longest large diameter culms available.

Do not use whole culms of green, unseasoned bamboo.

Avoid bamboo cut in spring or early summer. These culms are generally weaker due to increased fiber moisture content.

BAMBOO AS A REINFORCEMENT

In general, techniques used in conventional reinforced concrete construction need not be changed when bamboo is to be used for reinforcement. The same mix designs can be used as would normally be used with steel reinforced concrete. Concrete slump should be as low as workability will allow. Excess water causes swelling of the bamboo. High early-strength cement is preferred to minimize cracks caused by swelling of bamboo when seasoned bamboo cannot be waterproofed.

Concrete Mix Proportions

BAMBOO AS A REINFORCEMENTCONSTRUCTION PRINCIPLES

Bamboo reinforcement should not be placed less than 1-1/2 inches from the face of the concrete surface. When using whole culms, the top and bottom of the stems should be alternated in every row and the nodes or collars, should be staggered. This will insure a fairly uniform cross section of the bamboo throughout the length of the member, and the wedging effect obtained at the nodes will materially increase the bond between concrete and bamboo. Bamboo must be securely tied down before placing the concrete. It should be fixed at regular intervals of 3 to 4 feet to prevent it from floating up in the concrete during placement and vibration.

PLACEMENT OF BAMBOO

BAMBOO AS A REINFORCEMENT

Dowels in the footings for column and wall reinforcement should be imbedded in the concrete to such a depth that the bond between bamboo and concrete will resist the allowable tensile force in the dowel. This imbedded depth is approximately 10 times the diameter of whole culms or 25 times the thickness of 3/4 inch wide splints.

U. S. NAVAL CIVIL ENGINEERING LABAORATORY Port Hueneme, California By Francis E. Brink and Paul J. Rush

ANCHORAGE AND SPLICING OF REINFORCEMENTS

BAMBOO AS A REINFORCEMENT

Bamboo reinforcement in columns serves to resist a compression load equal to that taken by the concrete it displaces; it also will resist shear and tensile stresses. Of the full cross section of concrete, only 80 percent is considered effective in rectangular tied, columns. Allowable concrete stress should not exceed 0.225 f'c where f'c is the ultimate compressive strength of concrete.

U. S. NAVAL CIVIL ENGINEERING LABAORATORY Port Hueneme, California By Francis E. Brink and Paul J. Rush

BAMBOO COLUMNS

BAMBOO AS A REINFORCEMENT

Vertical Reinforcement Vertical reinforcement should be approximately 4 percent of the column cross section for rectangular columns. When bamboo is used as lateral tie reinforcement, the ties should be spaced not over 16 times the least dimension of the vertical reinforcement nor farther apart than the least dimension of the column. Enough ties should be provided so that every vertical bar is held firmly in its designed position and has lateral support equivalent to that provided by a 90-degree corner of a tie.

BAMBOO AS A REINFORCEMENT

The concrete cross-sectional area of bamboo reinforced rectangular columns conservatively should be 2.25 times the concrete area of steel reinforced rectangular columns, indicating a 50-percent increase in face dimensions. A common rule for determining the size of a tie is that its cross-sectional area is 2 percent of the area of all the vertical reinforcement confined by it.

BAMBOO AS A REINFORCEMENT

Bamboo columns are spaced at 1.2 M interval.Split bamboo grids are assembled with wire.Chicken wire mesh is fixed to the bamboo splits.Cement mortar plaster is applied to provide stability.The finished wall thickness is about 50mm thick.

BAMBOO AS A REINFORCEMENTwalls

Affordability Employment generation Availability of raw materials AdaptabilityFlexibilityTechnologyQuick to constructDurabilitySafetyComfortEnvironmental benefitsControl of deforestation

BAMBOO AS A REINFORCEMENT WHY BAMBOO

example

BAMBOO AS A REINFORCEMENT

Bridge for the "Bob MarleyMuseum" in Jamaica

Factory hall in Pennsylvania,Colombia [1993]

Rocco Yim

Michael McDonoughs chair

Bamboo may never replace concrete or wood entirely, but chances are that it will become a standard part of housing in the future. It identifies the potential for an alternative light construction method at low cost for areas where steel reinforcement might be prohibitive. In this case, bamboo might replace steel in light construction as the tensile element in concrete design. Due to the low modulus of elasticity of bamboo, flexural members will nearly always develop some cracking under normal service loads. If cracking cannot be tolerated, steel reinforced designs or designs based on unreinforced sections are required.

BAMBOO AS A REINFORCEMENTConclusion

It is a fact that the construction industry is the main consumer of energy and materials in most countries.The pursuit of sustainable development, that meets the needs of the present without compromising the ability of future generationsSome recommendations for future studies are proposed with the hope that the newly developed material could contribute, on a large scale, to sustainable development without harming our globe.

BAMBOO AS A REINFORCEMENTConclusion

Thank you

BAMBOO AS A REINFORCEMENT