Several major construction sites in Shenzhen, China have been temporarily closed due to reports of the use of cheap, unsafe and corrosive concrete. A public investigation revealed that several developers working in the city have been using concrete made with sea sand instead of river sand, which results in corroding steel reinforcements that can cause buildings to collapse. Among the projects halted is the Kohn Pedersen Fox-designed Ping An Finance Center, which is set to be the tallest building in China and second tallest in the world.
The investigation came across evidence that developers in Shenzhen have been using cheaper concrete made from untreated sea sand that contains high levels of steel-damaging salt and chloride. Those corrode steel reinforcements and compromise the stability of entire structures. The Shenzhen Housing and Construction Bureau reported 31 companies for the use of unqualified building materials, eight of which were deprived of the right to work in Shenzhen for a whole year.
Work on the Ping An Finance Center, designed by US architectural office Kohn Pedersen Fox, has been halted and the official investigation into the city’s concrete mixing plants has started. The 115-storey super-tall skyscraper was slated for completion by 2015.