Interim Report
Fabrication and Testing of
Jute Reinforced Engineered Bamboo Structural Elements
Dr V M Chariar
Centre for Rural Development and Technology
Indian Institute of Technology Delhi
November 2009
Fabrication and Testing of Jute Reinforced Engineered Bamboo Structural Elements
Abstract
The indiscriminate infrastructural growth is leading to rapid environmental
degradation. Steel, cement, synthetic polymers and metal alloys used for construction
activities are energy intensive as well as cause environmental pollution during their
entire life cycle.
To address this issue, research on non-polluting materials and
manufacturing processes have been taken up in the recent years. In this context, use of
bamboo which is fast growing and ecologically friendly material for structural
applications especially in a tropical country like India is being considered as quite
appropriate.
Studies show that steel requires 50 times more energy than bamboo to produce a
material equivalent of 1 m3 per unit stress. The tensile strength of bamboo is relatively
high and can reach up to 370 MPa. This makes bamboo an attractive alternative to steel
in tensile loading applications. This is on account of the fact that the ratio of tensile
strength to specific weight of bamboo is six times greater than that of steel. Therefore, in
this study it has been attempted to develop engineered bamboo structural elements for
use in rural housing. Bamboo slats derived from bamboo poles have been assembled
ined together and these are treated with epoxy to bring about structural bonding and
strength. Jute fabric as a reinforcement to improve the mechanical properties of
Engineered Bamboo Structural Element (EBSE) has been attempted under this study.
Table of Contents
1.
Introduction
Problem Definition and Objectives
1
2.
Literature Review
5
3.
Experimental Method
Equipments
Materials
8
4.
Fabrication of EBSE
13
5.
Properties Evaluation of EBSE
Tests on EBSE Beams
Tests on EBSE Columns
15
6.
Results and Discussions
21
7.
Applications of EBSE
23
8.
Conclusions
27
References
28
Annexure-I
29
Chapter One
Introduction
Indiscriminate infrastructural growth is leading to rapid environmental degradation.
Steel, cement, synthetic polymers and metal alloys used for construction activities are
energy intensive as well as cause environmental pollution during their entire life cycle.
To address this issue, research on non-polluting materials and manufacturing processes
have been taken up in the recent years. In this context, use of bamboo which is fast
growing and ecologically friendly material for structural applications especially in a
tropical country like India is being considered as quite appropriate.
Studies show that steel requires 50 times more energy than bamboo to produce a
material equivalent of 1 m3 per unit stress. The tensile strength of bamboo is relatively
high and can reach up to 370MPa. This makes bamboo an attractive alternative to steel
in tensile loading applications. This is due to the fact that the ratio of tensile strength to
specific weight of bamboo is six times greater than that of steel. Therefore, in the study
it has been attempted to develop engineered bamboo structural elements for use in
rural housing.
There are about 1500 species of bamboo. Some are much stronger than others.
Bambusa asissi and Dendrocalamus strictus are extremely strong. Guadua is extremely
tough. Some herbaceous bamboos are no stronger than reed. Some bamboos have very
thin walls but grow to larger diameters. Matching the bamboo to the application makes
for greater success.
The weakest direction of bamboo is perpendicular to the axis and tangent to a circle or
within the wall. Many applications of bamboo do require splitting the bamboo, making
this tangential weakness a real blessing. The fibers of bamboo can be pulled apart from
each other easily. Between the strength of longitudinal compression and low tangential
1
strength is the shearing force, when the fibers resist sliding past each other in direction
that they grow. The ability to withstand twisting forces is fair.
During the 1980's, the International Development Research Center (IDRC) began to take
note of people's reliance on bamboo. International wildlife expert Jane Stevens observes
that strong IDRC support for bamboo research has resulted in funding to the tune of
about 10 million dollars, used for national research programs involving more than 600
scientists and engineers in 14 nations (Stevens). These studies and experiments have
helped define the capabilities and strengths of bamboo, with the additional goal of
improving bamboo to make it a more competitive resource.
Table 1 Comparison of Bamboo with different construction materials
Use of bamboo is placed to address the four major global challenges:
•
Shelter security, through the provision of safe, secure, durable and affordable
housing and community buildings.
•
Livelihood security, through generation of employment in planting, primary and
secondary processing, construction, craft and the manufacture of value-added
products.
•
Ecological security, by conservation of forests through timber substitution, as an
efficient carbon sink, and as an alternative to non-biodegradable and highembodied energy materials such as plastics and metals.
2
•
Sustainable food security, though bamboo-based agro-forestry systems, by
maintaining the fertility of adjoining agricultural lands, and as a direct food
source, for example bamboo shoots.
1.1 Problem Definition and Objectives
Although potential of Bamboo in use as a construction material has been well defined,
but this is limited by its non-uniformity. The diameter, wall thickness, inter-nodal
spacing of bamboo all vary substantially even in a single bamboo of 2m to 4m length.
While working with bamboo duly taking into account its individuality may be
aesthetically and artistically satisfying, often the risk of the cost of the end product
being pushed far beyond the commoner’s reach is a sad reality. The current work puts
forward the concept of Engineered Bamboo Pipes which solve this problem of nonuniformity of bamboo pipes. Since Bamboo is plentifully available in the selected area,
and efforts are on to increase its production, successful demonstration of this
technology would result in applications that have not been hitherto pursued.
The purpose of developing bamboo products is to provide environmentally sound
construction alternatives to conventional construction materials, develop the rural
bamboo processing industry to increase income of rural people and also to improve safe
guard the environment. The EBSE elements can be used as substitute for concrete, steel
and wood used in housing and other products required in the day to day applications.
This project explores the use of jute reinforced EBSE elements using low cost production
process. Bamboo slats derived from bamboo poles have been both joined together and
these are treated with epoxy to bring about structural bonding and strength. Jute fabric
as a reinforcement to improve the mechanical properties of Engineered Bamboo
Structural Element (EBSE) has been attempted under this study.
Apart from non-uniformity, the applications of bamboo as an engineering material are
limited on account of difficulty arising in gripping and joining bamboo. If features of
uniformity, grippability and weldability are imparted to bamboo, the novel engineered
3
bamboo structural elements would be beneficial in multi-fold ways. It could find
applications in readily deployable columns and beams for construction, temporary
shelters, low-cost public shelters etc. These would function as prefabricated structural
units which can be mass-produced and assembled easily for construction of housings,
requiring little time, specialized skills and monetary input. Thus, these may be
employed for quick-shelters in calamity hit areas. Moreover, availability of EBSEs
would facilitate use as column elements in rural construction.
Also, several small entrepreneurs and fabricators in rural areas are looking to replace
steel with a low cost material. As a result of this technology, the small business of
replacing steel with bamboo which is impeded by the structural non-uniformity of
bamboo would get a boost. This would lead to wealth generation in the rural economy
and creation of several micro-enterprises. Once the technology is available in the field,
the same would be popularised. This would lead to the technology replicating widely
leading to value-addition and utilization of bamboo for high-end applications.
Entrepreneurship and employment generation activities would be sustainable.
The objectives of this minor project are;
•
Fabrication of Jute Reinforced Engineered Bamboo Structural Elements
•
Flexural and Compression Testing of Engineered Bamboo Structural Elements
•
Exploration of utilising Engineered Bamboo Structural Elements for housing
This minor project report has been divided into sections such as Literature Review,
Methods and Materials Used, Results and Discussions, Applications of EBSE,
Conclusion and References. The section on methods and materials used has detailed
descriptions on the materials and equipments used, fabrication process and testing
procedures, adopted in the EBSE production and testing procedures followed. The
analysis and basis for the calculations are provided in the last section as Annexure.
4
Chapter Two
Literature Review
Increasing global populación has significantly increased the demands of sustainable
building materials. A report reveals that currently about 1.4 million housing units are
built and it represents 55-60% of all the environmental impacts. It is also said that more
than 40 trees are required to build a good size wood frame house. The increased
demand of timber has caused global deforestation at the rate of 0.2% annually of the
total forest area that accounts for 7.5 million hectares of the forest.
Ghavami.[1] points to the use of bamboo to be superior than other construction
materials and their use in eco-construction and infrastructure especially with regards to
the choice of non-conventional materials and technologies, which are used not only in
developing countries, including Brazil. Bamboo has been found excellent building
material due to its versatile characterises. It is estimated that more than a billion people
live in bamboo houses mostly in developing worlds. Additionally, its ecological and
economical characteristics have made it a sustainable building material. Ghavami. [2]
Various testing, researches and practical experiences have revealed that bamboo has
high tensile strength, high strength to weight ration and high specific load bearing
capacity. Due to its long, strong and elastic nature of fibbers; bamboo is known as high
resistance to the earth quake. It has also natural insulation properties that would save
thermal energy and it is a very durable material if treated properly Bamboo is one of the
oldest and most versatile building materials with many applications in the field of
construction, particularly in developing countries. It is strong and lightweight and can
often be used without processing or finishing.
Alann. [3] proposes that durability and high variability among the properties present in
timber can be reduced by using glued-laminated timber. Investigations on various
reinforcement devices have been experimented to increase the strength of timber
structures. Lakkad. et al [4] studied the detailed mechanical properties of bamboo.
Mechanical properties of bamboo, mild steel, polyester resin and glass reinforced plastic
5
are compared. The mechanical properties of bamboo are found to compare favourably
with those for other reinforcing materials. As tensile strength of bamboo is greater than
that of resin, the author recommends bamboo fibre for reinforcement of plastic.
Typically, species like dendrocallamus giganteus (DG) have tensile strength of about
120 MPa, compressive strength of 55 MPa and Young’s modulus of 14 GPa. These
figures do not compare badly with mild steel which has an ultimate strength of 410
MPa, yield strength of 250 MPa and Young’s modulus of 200 GPa. Concrete has much
lower strength than those of bamboo reported here. In addition, the low density of
bamboo, which is typically 700 kg/m3, results in much higher strength to weight ratio
as compared to steel (density = 7800 kg/m3) and concrete (density = 2400 kg/m3). The
only shortcoming with raw bamboo is susceptibility to termite attack which can be set
aside by suitable chemical treatment.
Li. et al [4] has studied reforming the properties of bamboo using aluminium
composites. As the advantages of bamboo become well known, people are attempting
to experimentally build larger structures with bamboo. While there are many small and
temporary shelters made of bamboo, efforts are on to build larger and sturdier homes. It
is difficult for researchers to begin trial runs on bamboo homes due to existing
restrictions placed by the International Congress of Building Codes (ICBO). In Costa
Rica, engineers are developing safe ways to incorporate bamboo into household
structures. The country sponsored a National Bamboo Project in 1986 as a "new
technological approach to prevent deforestation in Costa Rica. The idea was to replace
the use of wood with an alternative, cost-effective, and seismically-sound building
material".
Bhalla et al [5] work on the use of bamboo as an engineered structural material, and sets
asides the conventional belief that only concrete and steel structures can be engineered.
In order to exploit fully the potential of bamboo as a construction material, various
structural components using bamboo concrete composites demonstrated them in
building houses using bamboo as a structural element, two bamboo arches vertically
6
separated are connected using Ferro-Cement Band ties to generate a Bow Beam Arch as
a load bearing member. Associated products such as bamboo based panels and bamboo
reinforced concrete also find applications in the construction process. In spite of these
clear advantages, the use of bamboo has been largely restricted to temporary structures
and lower grade buildings due to limited natural durability, difficulties in jointing, a
lack of structural design data and exclusion from building codes.
Studies have shown the potential of Bamboo in use as a construction material. But this
is limited by its non-uniformity. The diameter, wall thickness, inter-nodal spacing of
bamboo all vary substantially even in a single bamboo of 2m to 4m length. While
working with bamboo duly taking into account its individuality may be aesthetically
and artistically satisfying, often the risk of the cost of the end product being pushed far
beyond the commoner’s reach is a sad reality. The current work puts forward the
concept of Engineered Bamboo Pipes which solve this problem of non-uniformity of
bamboo pipes. Since Bamboo is plentifully available in the selected area, and efforts are
on to increase its production, successful demonstration of this technology would result
in applications that have not been hitherto pursued.
7
Chapter Three
Methods and Materials Used
In order to fabricate and test jute reinforced EBSE as columns and beams, bamboo slats
derived from whole bamboo of “Bambusa Tulda” variety which is chemically treated
was obtained from the Bamboo Lab functioning at Micro-Model Complex of IIT Delhi.
These slats along with materials procured and developed from the market such as
wooden nodal plates, jute cloth, epoxy and nails were used to fabricate the EBSE
column and beam elements.
The brief methodology adopted under the study is as
follows;
3.1 Equipments Used
• Bamboo Hydraulic Splitter Machine: It is used for splitting the bamboo to
required number of pieces. The machine is capable of splitting bamboo of
diameter 0.2 metre or 8 inches. Parallel or radial grills provided in the machine
enable splitting the operation. In case of board making plant, parallel edges are
required in for the bamboo splits. This can be achieved by using specially
developed grills. The grill has parallel blades, which split the bamboo to number
of pieces with nearly parallel edges. Grills with 'zero' centre can be used to split a
nearly solid bamboo. The machine also has the advantage to be paused at any
point of its operation, and thus even bent bamboo can be split, which increases
the productivity. Hence, the machine can be said to be able to split all types of
bamboo for both stick making and board making plants.
Fig: 1 Bamboo Hydraulic Splitter Machine
8
•
Internal Knot cum Skin Removing Machine: The machine is designed to clean
the internal knot as well as the outer skin of bamboo.
The machine uses
hardened chisels for the operation. Irrespective of the final product to be made,
the machine is a necessary part of any bamboo processing plant. There are two
chisels, one for removing the internal knot and one for removing the outer skin
of the bamboo split. In the process of cleaning the upper and the lower skin; the
output attains a flat surface on both the sides. This helps in further processing of
the splits. Maximum width of bamboo that can be fed 40mm, dimension of the
machine in meters 0.95X1X1.2, net weight 300kg, maximum material that can be
removed 10mm, power consumption 2.25kw or 3hp.
Fig: 2 Bamboo Internal Knot cum Skin Removing Machine
•
Bamboo External Knot Removing cum Skin Finishing Machine: This is
designed to clean the external knot as well as the outer skin of bamboo.
Removing of the outer skin and knot is very crucial for further operations on the
bamboo. Their cleaning assures longer life of cutters and chisels. The machine
uses specially designed carbide tipped external knot removing cutter. The cutter
is dynamically balanced and is suitable for all sizes of bamboo, i.e. up to 200 mm.
The machine is unique in itself, as for the first time it has been that easy to clean
the outer skin and knot of the bamboo. The operator has just to rotate the
bamboo and move it along the axis, and the skin and knot are cleaned by the
cutter, smoothly. Material removal rate can be controlled by setting the stopper
and hence even bent bamboos can be machined.
9
Fig: 3 Bamboo External Knot Removing cum Skin Finishing Machine
•
EBSE Machine: A manually operated special purpose machine was designed at
IIT Delhi to facilitate preparation of EBSE pipes and application of epoxy on the
element with ease. The unit has a resin bath, rotating shaft, shaft stand and a
handle for rotating the shaft after inserting the EBSE pipes to facilitate
application of epoxy coating.
Fig: 4 View of EBSE machine
3.2 Materials Used
•
Bamboo Slat preparation: In order to prepare the EBSE beams and columns,
treated bamboos of “Bambusa Tulda” variety were cut into 1.35m and 0.45m
length sizes and their external knots were removed using “External Knot
Removing Machine”. Using the “Radial Splitting Machine” the bamboo was
splitted into slats later. Further, the “Universal Bamboo Processing Machine” is
10
used to smoothen the bamboo slats from three sides which includes both the
sides as well as the internal surface so that they can be easily assembled together
to form flat strips. A nominal size of 20mm width and 5mm thickness slats were
chosen for making the EBSE beams. For columns, a nominal size of 20mm width
and 7mm thick slats were used.
Fig: 5 Slats derived from whole bamboo
•
Wooden Nodal Plates: The nodal plates are made up of normal country wood.
Size of the nodal plate is decided based on the desired dimension of the EBSE to
be fabricated. Nodal plates of 200mm dia and 20mm thickness have been used in
the study. A bore of diameter 45mm is provided at the centre of the nodal plates
to facilitate insertion of them on to the shaft assembly of EBSE fabrication
machine. For beams of 1.35m length, 3 nodal plates one at the centre and two at
the ends were provided. For columns of 0.45m length, 2 nodal plates at both ends
were provided.
11
Fig: 6 Nodal plates used for fabricating EBSE
•
Jute Fabric: Jute Hessian also termed as Burlap which is a fine quality jute fabric
has been used as reinforcment. This is commonly used as packaging material for
all kinds of goods. It is a plain weave cloth made wholly of Jute with single warp
and weft interwoven weighing not more than 576 grms/m2.
Fig: 7 Jute Hessian used as Reinforcement for EBSEs
•
Epoxy: Liquid epoxy Araldite (LY 556) having specific gravity 1.15-1.2, density
1.3 g/cm3 at 25ºC , flexural strength 110~120MPa, ultimate flexural elongation
5.5~6.5% , gel time of 600 minutes, with hardener Aradur (HY951) was used. For
each sample of laminated bamboo composite, the ratio of araldite and hardener
used was 100:23 by weight. A quantity of 200grams of epoxy was used per meter
length of the EBSEs fabricated under the study.
12
Chapter Four
Fabrication of EBSE
Using the manually operated special purpose machine designed for EBSE
fabrication, the EBSEs were fabricated. Nodal plates were inserted into the shaft of
the machine at centre and two ends for beams and at both end of columns. The slats
prepared were fixed to the nodal plates with a help of nails along with the jute farbic
one after the other. Reinforcment of jute is carried out according to the three designs
of reinforcement proposed under the study such as “outer, inner and alternate outer
and inner reinforcement”. After the initial development of the member, coating of
epoxy is applied uniformly using over the EBSE by fixing it on to the EBSE special
purpose machine. On rotation of the shaft, expoxy stored in the resin bath is
uniformly applied over the EBSE. Finally, finer finishing of the epoxy coating over
the EBSE surface is carried out by using a brush. The EBSE is later allowed to cure
before testing. For columns, a thick jute strap of 50mm wide was provided to have
confinement of slats at the outer edges as well.
Fig: 8 View of outer jute reinforced EBSE
13
Fig: 9 Sequence of Slat Preparation from Bamboo
Description
EBSE Beams
EBSE Columns
Span
1.31m
0.45m
Internal Dia
200mm
200mm
External Dia
213mm
217mm
3
2
Location of Nodal Plates
Ends (2) & Centre
(1)
Ends (2)
Type of Reinforcement
EBSE Fabricated Provided
Internal, External,
Alternate
- Total 3 nos.
Internal, External,
Alternate & No
Reinforcement
- Total 4 nos.
No. of Nodal Plates
Table: 2 Features of EBSE Beams and Columns Fabricated
14
Chapter 5
Tests on EBSEs
The EBSEs fabricated were subjected to both flexural and compressive strength tests
using Universal Testing Machine. The 3-point load tests for beams with a span of 1.31m
were carried out using a UTM to determine flexural strength and modulus of elasticity.
For the columns of 0.45m length, compression tests were conducted to determine
compressive strength and modulus of elasticity. Load and deflection values were
obtained for each specimen of the EBSE fabricated for the study purpose.
Fig 10 : View of Automatic UTM used for 3-point load test
5.1 Tests on EBSE Beams
The test for beams under 3-point load tests provided data for plotting the load versus
deflection curve. Maximum load and deflection was also obtained before failure of
beams under load (refer graphs given below). The following table provides, various
parameters obtained from the tests of EBSE beams.
Fig 11 : Testing of internal jute reinforced EBSE
15
Type of Jute
Reinforcement
Provided to
EBSE
Max.Load Deflection
Flexural
Strength
Modulus
of
Elasticity
Internal
13.8KN
63.11mm
16.8MPa
3988MPa
Alternate -Internal
and External
4.6KN
151.11mm
5.6MPa
7929MPa
External
17.7KN
65.77mm
21.55MPa
3988MPa
Table 3 : Test results of EBSE Beams obtained under 3-Point Load Test
Graph 1 : Test result of internal jute reinforced EBSE
16
Graph 2 : Test result of alternate internal and external jute reinforced EBSE
Graph 3 : Test result of external jute reinforced EBSE
5.2 Tests on EBSE Columns
The test for columns axial compression tests provided data for plotting the load versus
deflection curve. Maximum load and deflection was also obtained before failure of
17
columns under load (refer graphs given below). The following table provides, various
parameters obtained from the tests of EBSE columns.
Type of Jute
Reinforcement
Provided to
EBSE
Max.Load Deflection
Compressive
Strength
Modulus of
Elasticity
Internal
92.84 KN
19mm
16.67MPa
4968.82MPa
Alternate Internal and
External
82.98KN
14.3mm
14.90MPa
6036.9MPa
External
51.78KN
16mm
9.30MPa
4005.66MPa
No
reinforcement
68.78KN
14mm
12.35MPa
4893.80MPa
Table 4 : Test results of EBSE Columns obtained under Axial Compression Test
Graph 4 : Test result of non-jute reinforced EBSE (only with epoxy)
18
Graph 5 : Test result of internal jute reinforced EBSE
Graph 6 : Test result of alternate internal and external jute reinforced EBSE
19
Graph 7 : Test result of external jute reinforced EBSE
20
Chapter Six
Results and Discussions
The following are the interpretation of the experimental results exhibited by the EBSE
beams and columns during flexural and compression testes;
•
Failure of EBSEs has been observed mainly due to brittle failure of Epoxy matrix
especially when tested as beams. Bamboo slats used for the element fabrication
were unaffected in the loading. Use of different grades of epoxy, study of
different types of reinforcement and joints between slats can provide further
details of the properties.
•
Higher load carrying capacity was observed in EBSEs with jute reinforcement on
the outer surface. The beam carried a load of 17.7KN and a flexural strength of
21.55MPa. However, early failure of the column with outer reinforcement needs
further examination. This could be due to improper fabrication of the element
which has resulted in a early failure.
•
EBSE having alternate reinforcement on inner and outer surfaces showed high
level of ductility without failure of the epoxy coating due to better bonding
strength. Modulus of Elasticity of both the beam (7929MPa) and column
(6036.9MPa) fabricated with this reinforcement was higher than other types of
reinforced EBSEs.
•
Internal and External jute reinforcement of EBSEs showed higher load carrying
capacities while EBSEs with alternate external and internal jute reinforcement
showed greater ductility. The internal and external reinforced beams carried
about 13.8KN and 17.7KN loads respectively. The internal and external
reinforced columns carried 92.84KN and 51.78KN loads respectively
•
Failure of EBSE columns nodal plates due to shrinking of the upper portion and
bulging of the body while the load is applied on the element was observed. Use
21
of high strength wood like teak in place of the country wood will help in
improving the load carrying capacity of the columns.
Fig 12 : Failure of Nodal Plate and Bamboo Slat Joints due to Bulging of Columns
•
Use of square or rectangular jute EBSE for beams can help in increasing the load
carrying capacity with minimum deflection due to the increased surface area
available in the tension zones.
•
Having both outer and inner jute reinforcements to EBSE will improve the load
carrying capacity due to increased bonding strength with the epoxy coating.
•
The property of lower energy required for production and self weight of EBSEs
per unit stress developed can be a quite use element in the eco-housing
construction field in the future (Table-1).
•
The advantage of fabricating EBSEs for a required strength is possible due to the
mechanical fabrication process adopted. By adjusting the diameter of the EBSEs
this can be achieved.
22
Chapter Seven
Applications of EBSE
The EBSE beams and columns can be used in rural housing due to their increased
mechanical properties and durability. These also can be used as elements of household
furniture and other articles used in the day to day life due to their aesthetic appearance.
Weldability and durability of EBSE can be taken advantage for using them in
construction and for other purposes mentioned above. The advantage of localised
fabrication of EBSE in a rural area itself provides opportunity for local employment and
reduction of fabrication costs.
The cost economics of the EBSE of 1m length was worked out keeping a small scale
industry level operation. This is given as follows;
Details Amount (Rs.) Bamboo (30‐40 Feet) for preparation of slats 100 Labour for processing 300 Capital and running costs 50 Nodal Plates (2nos.) 80 Epoxy (200grams) 20 Jute (1sqm) 20 Total 570 Table 5 : Cost Estimate of Fabrication of 1 m long EBSE of 217mm Outer Dia.
23
A schematic plan of rural house which can be constructed is given below;
Fig 13 : Plan at Foundation Level
Fig 14 : Plan at Plinth Level
24
Fig 15 : Framing plan at Truss level
25
Fig 16 : Final View of the Structure with EBSEs
26
Chapter Eight
Conclusions and Scope of Future work
EBSE beams and columns can provide tailored solutions to the eco-housing initiatives at
cheaper costs. However, further studies to achieve higher mechanical properties and
understanding their behaviours in detail would make this a reality. Further work on
weladbility aspects can provide solutions to the use of EBSEs in the actual construction
of houses in rural areas.
27
References
[1]
Ghavami K. Eco-construction and infrastructure. RIO 3 - World Climate & Energy
Event, 1-5 December 2003, Rio de Janeiro, Brazil.
[2]
Ghavami K. Bamboo as reinforcement in structural concrete elements. Department
of Civil Engineering, Pontificia Universidade Catolica, PUC-Rio, Rua Marques de
Sa˜ o Vicente 225, 22453-900 Rio de Janeiro, Brazil, 2004.
[3]
Alann A. Fibres for strengthening of timber structures. Research report. Luleå
University of Technology, Sweden. February 2006
[4] Ahmad M. Analysis of Calcutta bamboo for structural composite materials. Virginia
Polytechnic Institute and State University, 2000.
[5] Lakkad S.C, Patel J.M. Mechanical properties of bamboo, a natural composite.
Fibre Science and Technology 14 (198(~81) 319 322.
[6] Li, S.H., S.Y. Fu, B.L, Zhou, Q.Y. Zheng and X.R. Bao. "Reformed bamboo and
reformed bamboo/aluminum composite." Journal of Material Science 33, 1998,
2147-2152
[7]
Bhalla S. Gupta S. Sudhakar P. Suresh R. Bamboo as Green alterative to concrete
and steel for modern structures. International Congress of Environmental
Research, Goa, 18-20 December 2008.
28
Annexure-I
Contd…
29
Computation
Moment of Inertia
Moment of Inertia of a hollow circular section can be found using the following equation;
Flexural Strength
Flexural Strength can be determined using the equation given below in megapascals;
Contd..
30
Flexural Modulus
31
32