On today’s show we are talking about buildings that are built so fast that they cannot possibly be structurally sound.
Guess what? They’re not.
These buildings have been called Tofu Dreg buildings.
It’s not unusual in China to see 30 story buildings being erected in a fraction of the time we see in North America. Sometimes in only a couple of months. That’s incredibly fast. These buildings are clearly visible during construction. There is a concrete slab being poured on top of a grid of concrete columns. Many of them don’t have proper shear walls.
Observing virtually anything in China is very impressive. They throw armies of people at solving virtually any problem. I’ve witnessed this first hand on visits to China. Many of the projects are built by very low paid migrant workers.
The problem with using this approach in construction is that these buildings are structurally unsound. Concrete requires time to cure and harden. Concrete buildings have forces to contend with apart from just gravity. The lateral loads on a building due to the wind can cause them to collapse like a house of cards.
The number of high rise building failures in China is alarming. We are talking about buildings that are less than 20 years old. These buildings should not be failing, not even after 50 or 100 years.
Host: Victor Menasce