"very nearly unbelievable _____ they made and used as much concrete as the the US did during the whole of the 20th century.

Looks like the quote came from Bill Gates via Vaclav Smi.

"Gates tells us that Vaclav Smil thinks cement is the most important man-made material."

http://www.dailykos.com/story/2014/06/13/1306854/-China-has-consumed-more-concrete-in-3-5-years-than-United-States-did-in-100-years-says-Bill-Gates#

All tis from the NET, so use your salt shaker vigorously.