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 building 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 Center 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 March 16, 31 companies had had their licenses to work revoked for at least six months.
Read more: Poor-Quality Chinese Concrete Could Lead to Skyscraper Collapses – Source: Wired