7. Applications II: Nanocrystallites in Cement: What Future After Two Thousand Years?

Cement nanocrystallites constitute the binding phase in concrete, a material that has been around for more than two thousand years and remains the most widely used of manufactured materials. Thanks to their size, their disordered nature, their reprecipitation after combination with water, and their rapid evolution when the concrete sets, these nanostructures have only been subjected to careful investigation quite recently. Nanotechnology is now able to control their formation and exploit their evolution (shrinking and swelling) during the setting phase to produce a concrete with a strength and ductility close to those of steels. Could this be the beginning of a new industrial revolution? Here we discuss the future of these nanocrystallites in new applications, considering not only the economic and industrial aspects, but also the issues of research and training.