INTRODUCTION Bamboo has been in wide usage since ancient times as a low-cost material for houses, bridges etc. Recently started appearing in designer homes as flooring, walling and paneling material Is viewed as a material preferred only by the poor or for temporary constructions Unpopular in conventional construction due to low durability, lack of structural design data, exclusion from building codes etc.
Facts about bamboo Bamboo is a perennial grass and not a tree as is commonly perceived. 1450 species are found in diverse climates across the world, however, not all of these are suitable for construction. One of the fastest growing plants on Earth. Its growth rate ranges from 30cm to 1 m in 24 hours. The strongest part of a bamboo stalk is its node, where branching occurs. Bamboo has also long been used as scaffolding; the practice has been banned in China for buildings over 6 storeys but is still in continuous use for skyscrapers in Hong Kong.
advantages Strength - Bamboo is an extremely strong natural fibre, on par with standard hardwoods, when cultivated, harvested, prepared and stored properly. Flexibility - Bamboo is highly flexible. During its growth, it may be trained to grow in unconventional shapes. After harvest, it may be bent and utilized in archways and other curved areas. Earthquake-resistance - It has a great capacity for shock absorption, which makes it particularly useful in earthquake- prone areas.
advantages Lightweight - Bamboo is extremely lightweight. Consequently, building with bamboo can be accomplished faster with simple tools than building with other materials. Cranes and other heavy machinery are rarely required. Cost-effective Economical, especially in areas where it is cultivated and is readily available. Transporting cost is also much lesser. Durability - As long-lasting as its wooden correlates, when properly harvested and maintained.
How to protect bambooUNTREATED BAMBOO Untreated bamboo has the following life spans in different conditions > Exposure to soil and atmosphere = 1-3 years > Under cover = 4-7 years > Very favourable conditions = 10-15 years Natural durability also depends on the species of the bambooPRE-HARVEST AND POST HARVEST PRECAUTIONS Felling during low sugar content season i.e. dry season Felling of mature bamboo Post harvesting transpiration Water soaking
How to protect bambooBORAX BORIC ACID PRESERVATION TREATMENTDepending on the At the preservationdiameter of the bamboo, treatment pool, bamboodifferent sized drill bits, soaks in borax-boric acidattached to a long steel solution (1:1.4) for 2 daysrod, are used to drill into to allow the mineral to Bamboo is removedthe centre of the bamboo penetrate all the nodes and stackedculms throughout their and diaphragms. vertically so thewhole length. solution can drain and be reused.
How to protect bambooBORAX BORIC ACID PRESERVATION TREATMENT Preservative solution isNext, the bamboo The bamboo poles recharged after four cycles bypoles are left to are left to dry adding water and the chemicals.bask in the sun slowly in a Preservation treatment costs adepending on the cool, dry place minimum charge of INR 4.50amount of sunlight until they are used per pole. for construction.
How to protect bamboo During the casting and curing of concrete, reinforcing bamboo absorbs water and expands The swelling of bamboo pushes the concrete away Then at the end of the curing period, the bamboo loses the moisture and shrinks back almost to its original dimensions leaving voids around itself The swelling and shrinkage of bamboo in concrete create a seriouslimitation in the use of bamboo as a substitute for steel in concrete. One effective treatment is the application of a thin layer of epoxy to thebamboo surface followed by a coating of fine sand.
How to protect bambooNEEM SEED OIL 90TREATMENT 80 70 Oil obtained from neem seeds 60can be used to improve water 50resistance and dimensional 40stability of bamboo culms 30particularly at high oil- 20treatment temperature. 10 0 Bamboo samples soaked in hotneem seed oil at 60C for 4hours had better waterresistance and dimensional Soaked bamboo samples at roomstability than samples soaked in temperature for 24 hoursoil at room temperature for 24 Soaked bamboo samples at 60C for 4 hourshours. SHRINKAGE REDUCTION
Bamboo foundationsCOMPOSITE BAMBOO-CONCRETE FOUNDATIONSSingle Post Footing Strip Footing
Bamboo foundationsBAMBOO PILES Bamboo compacts softsoil, thus increasing thebearing capacity of soil. The friction provided by theconstruction-grade bambooincreases its load-bearingcapacity. Treated split bamboo piles 8mlong and 80 to 90mm indiameter were filled with A sustainable house incoconut coir strands wrapped Thiruvananthapuram, Kerala where bamboowith jute. piles have been used as foundation . The foundation is further strengthened by bamboo reinforced concrete.
Bamboo foundationsBAMBOO PILES The sections were then tied with galvanised iron wire. After installation of the piles @2m c/c by drop hammer, the area is covered with a 2.5m surcharge of sandy material.
RESISTANCE TO EARTHQUAKES High residual strength to absorbshocks and impacts. Flexure coupled with its very lowmass. A bamboo house in Bhutan that withstood an earthquake that occurred at Sikkim (epicenter) measuring 6.9 in September 2011 Prototype house built with bamboosheet roofing and bamboo-reinforced 30 houses at the epicenter of aconcrete walls withstood a simulated 7.6 magnitude earthquakeearthquake measuring 7.8 on the survived without any damage inRichter scale Costa Rica in 1991
Comparative analysis Energy consumption during construction876543210 Concrete structure Wood structure Bamboo structure
Limitations and drawbacksFew considerations currently limit the use of bamboo as a universallyapplicable construction material Jointing techniques - Although many traditional joint types exist, their structural efficiency is low. Considerable research has been directed at the development of more e