INTRODUCTION…ø Bamboo has been in wide usage since ancient times as a low-cost material for houses, bridges etc.ø Recently started appearing in designer homes as flooring, walling and paneling materialø Is viewed as a material preferred only by the poor or for temporary constructionsø Unpopular in conventional construction due to low durability, lack of structural design data, exclusion from building codes etc.
Facts about bambooø Bamboo is a perennial grass.ø 1450 species are found in diverse climates across the world.ø One of the fastest growing plants on Earth.ø The strongest part of a bamboo stalk is its node, where branching occurs.ø Bamboo has also long been used as scaffolding material.
MECHANICAL PROPERTIES PROPERTY VALUE Density 0.5 – 0.9 gm/ccCompressive Strength 6.2 – 9.3 kN/sq. cm Tension Strength 14.8 – 38.4 kN/sq. cm Bending Strength 7.6 – 27.6 kN/sq. cmModulus of Elasticity 2000 kN/sq. cm Shearing Strength 2.0 kN/sq. cm
Usage Of Bamboo In Building ConstructionTypical Building Elements• Foundations• Floors• Walls• Roof• Trusses• Doors and Windows
Bamboo foundationsCOMPOSITE BAMBOO-CONCRETE FOUNDATIONSSingle Post Footing Strip Footing
Bamboo foundationsBAMBOO PILESø Bamboo compacts softsoil, thus increasing the bearingcapacity of soil.ø The friction provided by theconstruction-grade bambooincreases its load-bearingcapacity.ø 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 ø 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.
Bamboo Roofs and Trusses Fink TrussBamboo Tiles used for Roofing
How to protect bamboo…UNTREATED BAMBOOø 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 yearsø Natural durability also depends on the species of the bambooPRE-HARVEST AND POST HARVEST PRECAUTIONSø Felling during low sugar content season i.e. dry seasonø Felling of mature bambooø Post harvesting transpirationø Water soaking
How to protect bamboo…BORAX – BORIC ACID PRESERVATION TREATMENT Drill bits attached to a long steel At the preservation treatment rod, are used to drill into the pool, bamboo soaks in borax-boric centre of bamboo culms through acid solution (1:1.4) for 2 days to their whole length. allow the mineral to penetrate.
How to protect bamboo…BORAX – BORIC ACID PRESERVATION TREATMENT Bamboo is removed and stacked Next, the bamboo poles are left vertically so the solution can to bask in the sun depending on drain and be reused. the amount of sunlight
How to protect bamboo…BORAX – BORIC ACID PRESERVATION TREATMENT Preservative solution is recharged after four cycles by adding waterThe bamboo poles are left to dry and the chemicals. Preservationslowly in a cool, dry place until they treatment costs a minimum chargeare used for construction. of INR 4.50 per pole.
How to protect bamboo…ø The swelling and shrinkage of bamboo in concrete is a serious limitationin the use of bamboo as a substitute for steel in concrete.ø Treatment - Application of a thin layer of epoxy to the bamboo surfacefollowed by a coating of fine sand.
advantagesø Strength - Strong natural fibre, when cultivated, harvested, prepared and stored properly.ø Flexibility – During its growth, it may be trained to grow in unconventional shapes and may be utilized in archways and other curved areas.ø Earthquake-resistance – High shock absorption makes it particularly useful in earthquake-prone areas.
advantagesø Lightweight - Thus, building with bamboo can be accomplished faster with simple tools than building with other materials.ø Cost-effective – Especially in areas where it is cultivated and is readily available.ø Durability - As long-lasting as its wooden correlates, when properly harvested and maintained.
RESISTANCE TO EARTHQUAKESø High residual strength to absorbshocks and impacts.ø Flexure coupled with its very lowmass. ø A house in Bhutan that withstood an earthquake measuring 6.9 in September 2011 ø 30 houses at the epicenter of a 7.6 magnitude earthquake survived Prototype house built by EEVRC without any damage in Costa Rica in 1991
Comparative analysis12001000800600400200 0 Concrete Rate of construction per sq.foot in INR Bamboo
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 materialø Jointing techniques - Although many traditional joint types exist, their structural efficiency is low. Considerable research has been directed at the development of more effective methods.ø Flammability - Bamboo structures are not fire-resistant, and the cost of treatment, where available, is relatively high.ø Splitting – Low strength along fibres causes it to split or crack.ø Lack of design guidance and codification - The engineering design of bamboo structures has not yet been fully addressed. There is little or no data containing specifications of bamboo.
CONCLUSIONSø Based on the research results of bamboo obtained in universities and other institutes around the world the first norms for bamboo were created determining the physical and mechanical properties of bamboo.ø These norms have been evaluated by International Code Council and will be included in the ISO norms in near future.ø The results of the investigations show that bamboo can substitute steel satisfactorilyø There is a need to introduce formal education on the use of bamboo as a structural material in design and technical schools.