A sand scandal is brewing in China, with concerns that low-quality concrete has been used in the construction of many of the country's largest buildings -- putting them at risk of collapse.
The recipe to make concrete is pretty simple -- cement, aggregate and water -- but the strength of the final batch can vary wildly depending on the kinds of aggregate and cement used and the proportions they're mixed in. Commonly the aggregate used in many modern buildings projects consists of crushed gravel or other rock, including sand, and that's the cause of so much distress in the Chinese construction industry at the moment. Inspections by state officials have found raw, unprocessed sea sand in at least 15 buildings under construction in Shenzhen, including a building which, when finished, was set to become China's tallest.
The Ping'An Finance Centre is planned to top out at 660m, making it not only China's tallest building but the second-tallest building in the world after the Burj Dubai. 80m has been built so far, but construction has been halted in the wake of the revelation from Shenzhen's Housing and Construction Bureau that substandard sea sand concrete had been used in its construction. According to a notice on the Bureau's website posted on 16 March, 31 companies had had their licenses to work revoked for at least six months…..
It can take only a few decades for a building to become dangerously unsafe if untreated sea sand is used in its concrete -- including the possibility of collapse. While this scandal has been confined only to Shenzhen thus far, the possibility of it spreading to other Chinese cities is worrying. The country currently has nine of the 20 tallest buildings in the world that are under construction, while there were reportedly so many skyscrapers under construction in 2011 that it worked out as a new one being topped out every five days right through into 2014.
Yup, the wrong kind of sand – again.