Nickel use in Middle Eastern infrastructure

By Catherine Houska

Sustainable development is high on the agenda as construction in the Middle East emerges from the global recession and the region focuses on continued expansion after the boom years of the early 2000s. The need for longevity with service life requirements of up to 150 years, together with the area’s harsh climate, make nickel-containing stainless steels the materials of choice for both new buildings, such as Abu Dhabi’s Central Market project, and infrastructure.

Achieving long service life without replacement or significant maintenance reduces the direct costs of replacement and indirect impact associated with service disruption. It also minimises the environmental impact of raw material replacement and maintenance tasks. Stainless is used in applications ranging from reinforcing bar for sea walls and bridge decks, to stunning building exteriors, owing to its corrosion resistance, which has a direct effect on long-term sustainability.

Most stainless steels utilised in the Gulf are higher alloy nickel-containing austenitic and duplex stainless steels because of the aggressive environment. The nickel addition makes forming and welding of the steels much easier and they also provide a broader range of texture, colour and other finish options that are uniform in character and striking in appearance. Due to these factors, they are increasingly being used in cutting-edge regional designs.

In some coastal regions of the Gulf, such as in the UAE, Saudi Arabia and Qatar, the potential for exposure to sandblasting from windblown sand is unremitting, making it unwise to rely on corrosion-resistant coatings. Cars can have paint stripped off them in fully-fledged sandstorms. In many areas, there is constant particulate dust in the air that can increase corrosion rates, but buildings faced with stainless steels will always look good in the long term.

In order to obtain sustainability in design, construction and operation and to minimise negative effects on the environment, the World Green Building Council stipulates elevated rates of recycling and end-of-life recapture, durability and a positive impact on energy and water consumption. Nickel-containing stainless steels fulfil all these criteria.

Stainless steels are 100 percent recyclable and can potentially be refurbished and reused indefinitely. While the average recycled content is 60 percent, some producers report up to 90 percent, while 92 percent of stainless used in architecture and construction is recycled into new metal, rather than being sent to landfill.

Stainless steel roofing, sunscreens and wall panels score highly on the solar reflective index as they absorb less heat than many other construction materials, so reducing demand for energy from air-conditioning. It is also healthy, in that stainless does not create toxic run-off that can damage the surrounding environment or produce harmful chemical emissions when deployed inside buildings - unlike carpet and drywall - allowing a wide range of attractive interior finishes to be used. Stainless steel buildings require only the application of ordinary, non-environmentally damaging, household detergent or window cleaner to keep their exteriors clean.

A great deal of infrastructure continues to be erected in the Middle East, from sea walls and building foundations to bridges. Because the soil, air, water, sand and concrete in coastal areas has a very high sea salt (chloride) content, the employment of stainless for both reinforcing bar and other structural components can provide infrastructure capable of 100 or more years of life, as well as seismic and fire protection and security against blast impact.

Stainless steels are also important in minimising the use of precious potable water and are used extensively in desalination plants and in building systems for capturing and reusing grey (waste) water such as tanks, piping and filtration systems, so that waste water can be utilised for other purposes, for example for flushing toilets and irrigating landscapes.

All in all, nickel-containing stainless steels could not be a better choice for ensuring sustainability in construction in the Middle East.

Further information can be obtained from the Nickel Institute, a not-for-profit organisation that represents the interests of the companies that together produce more than 90 percent of global annual nickel output on www.nickelinstitute.org.

Catherine Houska, one of the world's leading authorities on nickel-containing stainless steels in architecture, is architectural consultant to the Nickel Institute.