• Overview Of Bamboo
• General Characteristics
• Concrete Mix Proportions
• Placement Of Bamboo
Properties Of Bamboo
• Comparison Of
Bamboo And Steel
3. Overview Of Bamboo
Basically bamboo is a perennial grass belonging to the class monocotyledonous, and is
approximately almost 600 species recorded throughout the world .
Several countries did research on bamboo reinforcement and have noticed that the major
advantage of bamboo lie in it relatively high tensile strength .
The principal problems associated with bamboo reinforcement are bond, volume change and
possibly decay .
So, there should be further research concerning bond mechanisms, means of improving bond
strength, methods of controlling volume changes, decay and the behavior of bamboo under loadterm of repeated load .
Bamboo was given recent consideration for use as reinforcement in soil cement pavement slabs
in which the slabs behave inelastically even under light loads .
4. General characteristics
• The specific gravity of bamboo
varies between 0.4 and 0.5 .
• The ratio of tensile strength to
specific weight of the bamboo
is about 6times that of steel
• The strength of bamboo is high
in parallel direction to the
grains and less in
perpendicular direction .
The following factors should be
considered in the selection of
bamboo culms(whole plants) for
use as reinforcement in concrete
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 in
early summer. These culms are
generally weaker due to increased
fiber moisture content .
When possible, the bamboo
should be cut and allowed
to dry and season for
three to four weeks before
using. The culms must be
supported at regular
spacings to reduce
Bamboo can be permanently
bent if heat, either dry or
wet, is applied while
applying pressure. This
procedure can be used for
forming splints into Cshaped stirrups and for
putting hooks on
Splints(split culms) are generally more desirable than whole culms as
Larger culms should be split into splints approximately 3/4 inch wide .
Whole culms less than 3/4 inch in diameter can be used without splitting .
Splitting the bamboo can he done by separating the base with a sharp knife and
then pulling a dulled blade through the culm.
The dull blade will force the stem to split open; this is more desirable than
cutting the bamboo since splitting will result in continuous fibers and a nearly
The following table shows the approximate
Diameter (in.) Area (sq. in.)
net area provided by whole culms and by
3/4-inch-wide splints .
7. Concrete Mix Proportions
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.
8. Placement Of Bamboo
Bamboo reinforcement should not be placed less than 1½ inches from the face of the
concrete surface .
The clear spacing between bamboo rods or splints should not be less than the
maximum size aggregate plus ¼ inch .
Reinforcement should be evenly spaced and lashed together on short sticks placed at
right angles to the main reinforcement .
The ties can be maid with vegetation strips .
This embedded depth is approximately 10 times the diameter of whole culms or 25
times the thickness of ¾ inch wide splints .
Spacing of the stirrups should not exceed 6 inches .
9. Design Principles
Bamboo reinforced concrete design is similar to steel reinforcing
design. Bamboo reinforcement can be assumed to have the following
Mechanical Properties Of Bamboo
Ultimate tensile strength
Allowable tensile stress
Allowable bond stress
Modulus of elasticity
2.5 x 10^6
10. Comparison of Bamboo And Steel
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 .
The environmental and financial comparison demonstrates that
bamboo can compete with building material.
Bamboo is a natural product and will therefore always have some extent
It is therefore suggested that the bamboo culm should be used in
functions were the measurement requirements are not entirely precise
or fixed, as in temporary buildings (e.g., pavilions and tents) or small
Furthermore, bamboo can play a role as a non-supporting or finishing