Corrosive concrete halts construction
of China's tallest building

| 14 comments

Pingan International Finance Center by Kohn Pedersen Fox

News: concrete made with unprocessed sea sand has been found in at least 15 buildings under construction in Shenzhen – including what will be China's tallest building when completed – putting them at risk of collapse.

An industry-wide investigation made public last week discovered that 15 buildings in the city were partly constructed from concrete made with sea sand instead of river sand, including the 660-metre-high Ping’an International Finance Center, expected to be the second tallest building in the world.

While cheap sea sand offers cost-saving opportunities for contractors, the salt and chloride present in it can corrode steel reinforcements over time and ultimately cause a building to collapse.

The Shenzhen Housing and Construction Bureau found that 31 companies had violated industry rules and ordered eight of them to suspend business for one year in the city, Bloomberg reported.

Construction has now been halted on Ping'an International Finance Center, which was designed by US firm Kohn Pedersen Fox and has been under construction since 2009.

Like many Chinese cities, Shenzhen is undergoing a frenzy of construction activity, with architects including OMA and Mecanoo working in the city.

OMA recently won a competition to design a financial office tower, the firm's second building in the city after the Shenzhen Stock Exchange. Mecanoo are woking on a cultural complex in the Longgang district, while the Futian District - an area that's larger than Manhattan - is being redesigned by SWA Group to create pedestrian areas and green spaces.

See all our stories about architecture and design in China.

Image is by Kohn Pedersen Fox.

  • Kris

    China: builders without conscience.

    • T,.T

      Not the builders themselves actually – it’s the main/sub-contractors with no conscience.

      • Kris

        Pedantic.

  • ZumthorFanatic

    It ain’t China if the material ain’t sub-standard, LOL.

  • Pedro

    That’s what happens when constructors don’t follow the guidelines of good practice. It is widely known that sea sand can’t be used to make concrete if the salts aren’t removed, a procedure that increases the overall cost. If they don’t do it, not only will the concrete degrade faster but it also corrodes the internal steel at a much faster rate. River sand is more commonly used for that matter. What surprises me the most is the lack of supervision that made it possible for this to happen.

  • William

    Let’s hope they will also investigate recently finished buildings by those contractors. Building cheap ànd fast too often sacrifices quality and durability in the process.

  • Confucius

    Feng shui master say building can go to sky! He say sea-sand good – used since time of grandfather. Dawn of time. No worries. You give me money now!

    - Confucius

    • Lucian

      How about no?

  • Brian

    I can see the site from my office. Fortunately, it isn’t that far out of the ground. The service core is only 10-15 stories. I guess I’ll be hearing the sounds of demolition soon.

  • marvin

    It’s the equivalent of tainted baby formula for concrete.

  • Steve

    This is actually pretty common in coastal areas. The cost of clean aggregates can be extremely high, and many areas of the world have to import sand specifically for high strength concrete. I’m just surprised that the contractor tried to pull this scam on such a high profile building backed by local government.

  • Craig

    They’re back on site and working again at the Ping’an Financial Centre Site this morning. Our office directly overlooks the site. Seemingly given some sort of all-clear to continue. The structure for KPF’s Ping’an Financial Centre is primarily a braced steel lattice with the concrete essentially a casing around the structure. This may have some bearing on the decision to continue.

  • clifford camacho

    Still wondering why? Haven`t you heard about fake milk, fake eggs, fake Louis Vuitton, bursting tires and still a lot more fake products that are made in China?

  • Kenneth Smythe

    Best practice and making a profit may just be mutually exclusive ideas in China.