The construction sector in India is emerging as the largest end-user of aluminium which is finding ever new applications due to qualities that make it an ideal replacement for wood and steel. This low density metal is non-corrosive and is considered a green material due to its high recyclability. Aluminium’s incredible strength-to-weight ratio enables it to go into designing of light structures with exception stability. As cities opt for vertical growth, the metal finds more takers as it is easy to carry to heights. It also lends itself to endless forms inasmuch as it can be sawed, welded, drilled, bent, soldered, screwed and cut into any conceivable and dynamic 3-D shape.
But more than anything else, aluminium is rated highly for its recyclability. It is pointed out that recycled aluminium accounts for one-third of global aluminium usage. Going by the increasing use of aluminium in modern buildings, it is guessed that today’s buildings would constitute “urban mines” of around 400 million tonnes of aluminium metal that can be extracted and recycled by future generations through the use of only five per cent of the originally used energy, not just once but repeatedly. A Delft University of Technology study of six European buildings found that 92 per cent of the aluminium used there was actually recycled.Consumption growing
Consumption of aluminium is growing globally at a rate of 4.8 per cent on a year-on-year basis. The construction sector is the key driver behind its growth with nearly 13 per cent of it being claimed by the construction industry in India. Extrusions claim another 10 per cent, automotive sector 18 per cent and wires and cables taking as much as 31 per cent. India has emerged as the eighth largest producer of primary aluminium and has three per cent current share in world production. Contrastingly, in China the building and construction industry claims 35 per cent of domestic consumption.
T.M. Thomas, principal architect at Thomas Associates, says that in the 1970s when he was setting up his firm, wood was principally used for doors and windows but has been replaced by aluminium in a major way. He says aluminium is visually attractive, needs least maintenance and can be used widely for interior partitioning and also as supporting structure for ceilings. V. Gopal, executive director, Prestige Group, says construction work is on over 55 million sq. ft. of space currently under the company and it is taking around 1,500 tonnes of aluminium. He says 12 to 16 per cent of the budget goes for façade in commercial buildings today and aluminium takes the major component of this budget.
Ian Smith, Managing Director, Sapa Building System India, says that in Europe, 40 per cent of the aluminium demand is met by recycled metal with 96 per cent recovery from some demolished buildings. An expert in aluminium use, Smith says aluminium offers uniqueness of design, fits neatly with glass, gives elegant facades, and is highly adaptable to heating and cooling system whenever needed. According to Chris Bayliss, deputy secretary general of International Aluminium Institute, 75 per cent of the originally produced aluminium in the world was still in use somewhere in some form. K.S.S. Murthy, general secretary of the Aluminium Association of India (AAI), says aluminium is much safer than PVC windows and doors and urges the Bureau of Indian Standards to take up standardisation of windows and doors which will enable the builders as well as the public at large to avail themselves of standardised material.
Mr. Gopal adds to the list the fenestration material among which aluminium takes the major share. Prof. Murthy informed the participants at a recently held seminar organised by the AAI that the Karnataka Government will be setting up an aluminium park in the State which will greatly benefit the downstream industry. Mr. Thomas adds a note of caution too. He says India needs to address the long-term perspective as availability, affordability and heavy taxes are affecting the growth of the aluminium sector in the country. He also feels the necessity for training centres to train workers applying aluminium in construction.
The high reflectivity of some aluminium alloys makes it a very efficient material for light management. Aluminium solar collectors can be installed to lower energy consumption for artificial lighting and heating in winter while aluminium shading devices are used to reduce the need for air-conditioning in summer.Lavish use
Of late, several iconic buildings with lavish use of aluminium have come up around the cities of the world. The Commerzbank building clad in anodised aluminium rain screens panels has been adopted as the symbol of Frankfurt by Financial Times . Beijing’s Sino-Italian Ecological and Energy Efficient Building (SIEEB) on the Tsinghua University campus was designed by the Italian architect Mario Cucinella. This building with 20,000 sq. m space targets energy efficiency and minimal CO emission. Yenchep Bridge in Australia (143 metre long and 2.5 metre wide) significantly reduces long-term maintenance cost. The Nasher Sculpture Center in Dallas (Texas, U.S.) uses cast aluminium shells which create an environment with optimum conditions for displaying sculpture by Ray Nasher, who owns the world’s largest private sculpture collection.