Why Choose Aluminium

Why should I choose Aluminium?

The essential characteristics of aluminium make it an ideal material for construction.

It is light, strong, durable and requires minimal maintenance. It is flexible and easy to handle - this gives it tremendous potential for design. It can be curved, tapered, welded and cut to the most challenging and dynamic geometries. Where it is cut, the metal's innate resistance to corrosion means that the trimmed edge does not need to be protected.

The natural oxidisation of aluminium creates an ever present barrier to atmospheric attack. Inert and hard, the oxide protects the underlying metal, reforming spontaneously if damaged or scratched. An integral part of the metal, this oxide layer thickens very slowly with age and darkens gradually according to the level of atmospheric pollution.

Common industrial pollutants such as ammonia, carbon monoxide and carbon dioxide all have very little effect on aluminium. Aluminium is also excellent to use in coastal and marine environments because the effect of sodium chloride on the metal is minimal.

Aluminium is non-combustible but it melts at 600°C. This means that in the event of a serious fire a roof constructed of 2 skins of aluminium with non-combustible insulation will have a sacrificial function. The roof will melt over the seat of the fire allowing it to vent rapidly through the void thereby saving the structural frame of the building.

There are many aluminium alloy compositions available on the market, each with their own specific characteristics and properties.

History of Aluminium

Although aluminium is the third most plentiful element known to man, it was only in 1808 that Sir Humphrey Davy established its existence. Some 17 years later, the Danish scientist, Oersted, produced the first tiny pellet of the metal and in 1845 German scientist Wohler established one of its outstanding characteristics - lightness.

Research into aluminium then shifted to France, enabling Henri Saint-Clair Deville to display a solid bar of the metal at the Paris Exhibition in 1855. The production cost made it more precious than gold, silver or platinum at that time and it attracted the interest of Napoleon III, who became enthusiastic about its potential as a military material.

Following several attempts to make the metal commercially viable, two unknown young scientists, Frenchman Paul Louis Toussaint Heroult and American Charles Martin Hall, working separately and unaware of each other, came up with the same new process in 1886. Their discovery sent the price of aluminium tumbling from $18 to $4.50 per kg. The first aluminium production companies were subsequently founded in 1888 in France, the United States and Switzerland.

The statue of Eros in Piccadilly Circus erected in 1893 is an early example of the use of aluminium. In 1897, aluminium sheet was used to cover the roof of San Gioacchino church in Rome. Still in excellent condition today, this building proves unquestionably the weathering properties and longevity of aluminium.

Aluminium and the Environment

Aluminium is the most abundant metallic element on earth, making up approximately 8% of the earth's crust. Indeed, of all the elements, aluminium ranks a proud third behind oxygen and silicon as the most commonly occurring. At the present rate of usage (and not allowing for the fact that 70% of all aluminium used is recycled at the end of product life) at least 300 years supply has already been identified.

Whilst the process of isolating aluminium from ore consumes a large amount of electricity, two-thirds of this processing now uses electricity generated without CO² emissions - hydro-electric power.

Newly developed processes for re-cycling have reduced energy consumption by 80-90% in comparison to aluminium production from ore. Reprocessing now produces a high quality aluminium without loss of properties and there is no requirement to mix the recycled product with 'pure' aluminium from ore. Re-cycled aluminium can also be alloyed with other elements to achieve specific performance characteristics. Thus, with an ever-increasing proportion of re-cycled metal in use, aluminium can be accurately described as the ultimate 'sustainable' material. Building sheet for instance, is reprocessed and used for key motor vehicle components

RECYCLING CHECKLIST

The recyclability of aluminium - one of its unique properties along with strength, durability and corrosion resistance - has led to its increased use in construction over recent years. Used aluminium is valuable and is easily and endlessly recycled without quality loss. The material is very rarely 'lost' entirely because of this. Important issues to note are:

The quality of aluminium is not impaired by recycling, endlessly

Remelting aluminium saves up to 95 per cent of the energy needed to produce the primary product

It is the most cost-effective material to recycle

The overall market for used aluminium is steadily growing, so the more aluminium there is in a product, the more chance it has of being recycled

The recycling rate of used aluminium products in building is over 80 per cent
(over 95 per cent in transportation and 30 per cent in packaging.

30 per cent of the 1.9 million tonnes of aluminium used in Europe in 1997 came from recycling.