Bamboo is a versatile construction material with a long history of use in buildings and other structures such as bridges in tropical regions, including parts of India, Southeast Asia and South America. There are as many varieties of bamboo as there are uses to which it can be put.
While it has always been extensively used in regions where it grows easily, it has generally been unfairly overshadowed by more glamorous industrial material such as concrete and steel in the 20th century. However, with an urgent search on for environment-friendly construction material, architects, engineers, furniture designers and even artists are beginning to rediscover the enormous possibilities of bamboo.
There are good reasons for this interest. Wherever it is available, bamboo is much cheaper than higher-grade timber while being stronger in some ways. A kind of grass, it grows really fast—sometimes in two years—compared to teak, which can take up to 25 years. It also grows in many different soils, even on fallow land, and can be planted with other crops—though with some segregation to ensure it doesn’t eat into their share of soil nutrients.
Bamboo architecture has always been very elegant. Think of the curved silhouettes of the pagoda roofs of Southeast Asia, whose form derives from the tendency of bamboo roofs to sag with weight but remain stable. Then, there is the work of contemporary Colombian architect, Simon Velez, with bamboo frameworks that are delicate and yet monumental. Bamboo is lightweight, but strong in resisting compression (axially) as well as tension. These qualities allow correctly detailed bamboo buildings to be light, strong and capable of resisting cyclonic and seismic forces. For the ecologically sensitive, the beautiful colours of bamboo only add to its attraction.
Today, bamboo is being used by itself as well as in combination with other material, as at the Inspiration office in Kochi. The crucial problem with bamboo assemblies or composites is that of jointing and bonding. Because of its pipe-like form, the jointing of bamboo members in frameworks needs careful attention. Pre-modern craft traditions used natural fibres to tie and lash joints. Contemporary builders and researchers have tried a variety of connectors including metal. The problems are different when bamboo has to be used in a composite element, for instance, with layers of concrete, as at the Inspiration office. K.R. Datye, an eminent engineering consultant, has developed a range of innovative structural systems to overcome bamboo’s inability to bond directly with cement and concrete. His system, used at the Inspiration office, is based on splitting the bamboo into strips so as to get flatter members that are easier to work with.
Bamboo buildings need protection from bio-attack and fire. The Inspiration building is raised above water to protect it from insects and rising dampness. Bamboo components can be treated against insects with copper-chrome borax, and with sodium tetraborate for fire resistance.
Bamboo faithfuls are in august company. Richard Rogers, the international icon of high-tech architecture, won the Stirling Prize of the Royal Institute for British Architects last year for the Barajas Airport in Madrid. It uses bamboo in its roof, though apparently only as internal covering. President A.P.J Abdul Kalam is a staunch supporter of a national bamboo mission as a route towards employment generation.