State inspectors in Shenzhen, China, have found at least 15 local plants producing concrete with unprocessed sea sand. Thirty-one companies have been cited for violations, and eight were ordered to suspend business for a year. Construction on multiple projects in Guangdong Province—including the 660-m Ping'an Finance Center—has been halted during the inspection. (Only 80 meters of the Ping'an building has been erected so far; China Construction First Building Group Corp. Ltd. is the primary contractor.)
Unprocessed sea sand is illegal to use as an aggregate in concrete because its chlorine and salt content are corrosive to steel, causing buildings to degrade and potentially collapse within a few decades. River sand, the preferred material, costs twice as much and is in short supply.
The scandal is currently confined to Shenzhen but could spread to other cities given the obvious financial incentives for using sea sand. Inspectors also found that two large sand pits were using seawater instead of fresh water to rinse sand, also a problematic practice.
Industry experts express particular concern because China currently has nine of the putative 20 tallest buildings in the world currently under construction, as well as many other skyscrapers.