The world’s fastest growing woody grass is Bamboo. It grows approximately 7.5 Cm to 40 Cm a day with the world record being 1.2 m in 24 hours in Japan. Bamboo grows three times faster than most other species. Species of Bamboo that are commercially used usually mature in four to five years. Different harvests are feasible every second year for up to 120 years in some species and indefinitely in some others. Construction companies have recently become more cautious about the building materials they use in projects, knowing how some materials have negatively impacted the environment in the past.
With increased knowledge of the environmental effects that some materials can give off, society may have noticed the recent use of bamboo as a building material. Bamboo is a building material or construction material throughout the world’s tropical and sub-tropical areas. Bamboo is a sustainable and versatile resource.
Utilisation of bamboo in different forms of building construction
Bamboo can also be utilised to make traps, cages, tools or instruments, weapons, bridges, pontoons, raft, tower, fence, water wheels, irrigation pipes and many different things. It is extensively perceived as one of the main significant non-lumber forest resources due to the high socio-economic advantages of bamboo-based items.
In ancient times, bamboo used in its natural form is seen to be associated with the cultures of South Asia, East Asia, South Pacific, Central, and South America. As time passes now, it is started to be used for supporting various suspension bridges, skyscrapers, ladders, as architecturally design masterpieces to give a smooth aesthetic finishing look as fencing, gates, gutters, fountains, etc and so on.
First structural design codes for bamboo were published by ISO in 2004
After several significant research of elements and joints, the first structural design codes for bamboo were published by ISO in 2004 under its physical, mechanical, and structural properties which leads to modern and advanced use of bamboo in construction workshops.
Bamboo is a giant woody fast-growing plant having a hollow jointed stem with high compressive and tensile strength. Bamboo of age 3-6 years are favorable for construction purposes.
Due to its properties of greater tensile strength, compressive strength, elastic modulus, anisotropic, good fire resistance, flexural strength, shearing strength high, flexibility, lightweight, easy workability, and availability; it is widely used in the construction field.
Bamboo has very strong fiber with compressive strength twice the concrete and tensile strength near to steel. It can be curved without breaking due to the strong and flexible fiber present in it. Because of these advantageous physical and strength characteristics, bamboo is suitable material for the application in different types of structures and constructions.
Applications of bamboo as a construction material:
Some applications of bamboo as a construction material are (i)Bamboo is light in weight, flexible, ductile, and strong. So, it can be easily used for the construction of trusses at a low cost.For making frames; properly seasoned/ dried straight bamboos are utilized. Corrugated Bamboo Roofing Sheets can be utilized. (ii) Bamboos can be utilized for making bamboo walls. They should be protected from moisture using (2-3) coats of rubber tree oil before application. (iii) For a sustainable and economically accessible aesthetic interior look; bamboo has been used in framing doors, windows, balconies by weaving bamboo strips as matting or a palm leaf.
(iv)Bamboo can be laminated into sheets and flattened by splitting large culm.Corrugated Bamboo Roofing Sheets are available in the roofing market. (v)Bamboo can be used in place of reed boards which are mainly used for thermally insulating ceilings and interior walls. Reed boards are generally made from natural reeds having rigid jointed hollow stem-like bamboo. (vi)Because of properties like lightweight, easy transportation, low cost, flexibility, and high strength; bamboo is widely used as scaffolding. Bamboo is utilized as scaffolding in the construction of small structures (buildings, culverts, etc.) to heavy structures (Bridges, Skyscrapers, etc.).
(vi) In many flood or landslide-prone areas; bamboo can be installed as retaining materials.It is more secure to harvest bamboo near to river bank as it holds the soil strongly, not letting it erode with high-velocity flow water. (vii)Bamboo has an essential structural behavior. The placement of Bamboo as a structural reinforcement is similar to iron/steel reinforcement rods in concrete.
Importance of bamboo treatment
A thorough treatment of Bamboo is required to protect it against insects and rot before it is put into use. Commonly a mixture of Borax and Boric acid are utilized for this purpose. Another procedure generally employed is to boil cut bamboo to remove the starches that draw insects. Some precautions to apply before using bamboo are: (i) Even a small amount of defect (decay) due to natural toxins or beetle/termite / fungal attack can bring change in the strength capacity of bamboo. (ii) Bamboo must be kept dry throughout its use to maintain the tensile and compressive strength of its fiber. (iii) Bamboos quality should be tested using different methods to prevent upcoming hazards and damage during designation and after construction. (iv) Uniformity in length and diameter of bamboo should be considered properly that is to be used in the construction. (v) Public awareness should be given that it is just a myth/misconception that bamboo is inferior to wood incapable to be used to provide strength to the structure.
Merits of bamboo as construction materials
Some merits of bamboo as construction materials are: (i) Bamboo can be curved: It is a fast-growing plant with high tensile fibers. Thus, with adequate heat and pressure, it can be curved/bent up to a certain limit of extension. It is flexible in nature. (ii) It has a non-linear stress-strain behavior. (iii) It is more durable compared to other kinds of wood items if prevented from decaying and exposure to moisture and fungi for a long time. (iv) It has energy-absorbing and higher bending strength that can be ideally used for seismic-resistant construction. (v) It is easily available, can be repaired, handled, cut, maintained, and repositioned due to its lightweight.
(vi) Bamboo is an eco-friendly construction material. (vii) It can be used for a retaining purpose near river banks to check overflow of water preventing erosion of bank soil. (viii) For architectural decorations and design; bamboo gives an enhancing look to structures. Thus, it is economically accessible. (viii) It is easy to transport, store and handle. (ix) By cutting stalks of bamboo into thin strips and drying, it can be laminated into sheets and planks. These sheets and planks have been used in flooring cabinetry, furniture, and decoration purposes at present. (x) It is fire resistive in nature due to the presence of a high value of silicate acid and water. (xi) It poses no danger to health.
Demerits of bamboo as construction materials
Bamboo comes with its own set of drawbacks such as: (a) Requirement of preservation. (b) It shrinks greater when loses water. (c) For making it durable; lots of treatments are required. (d) Reliability of bamboo is questionable despite its lightweight, high strength, and ductility.
Since time immemorial, bamboo has played an important role in the development of mankind. It is used for a wide range of day-to-day purposes, both as a woody material and as food. It has been the backbone of much of the world’s rural life and will remain so as the population increases. The properties as top grade building material and increased availability of bamboo in our country makes it possible to use bamboo in the field of construction extensively. Its highly valued utilisation not only promotes economic development, but also saves forest resources to protect our ecological environment as a wood substitute.
As an economic building material, bamboo’s rate of productivity and cycle of annual harvest outstrips any other naturally growing resource. If today you plant three or four structural bamboo plants, then four or five years later you will have mature clumps, and in eight years you will have enough mature material to build a comfortable, low cost house.
After the hot issues of global warming and sustainability, bamboo is being used as a substitute in place of high-quality woods for construction (to reduce deforestation as the wood takes time to regrow and use as construction material) because bamboo can be harvested in a short time of three-five years.
(The views expressed are normal)