Concrete is the material to thank for most of our architecture miracles. It can be used in amounts that are both impressive and a tiny bit frightening. For example, the world's record for the largest concrete pour in a single project belongs to the Three Gorges Dam in Hubei Province, China and it required 16 million cubic meters of concrete over 17 years of construction.
Concrete is sometimes also called Portland cement concrete for its visual resemblance to Portland stone and is made of coarse and fluid ingredients in order to harden not instantly but over time. This allows for it to be worked into the most precise designs.
This is one of the most frequently used building materials and was first used as long ago as 700 BC. Ancient Nabataeans used concrete-like materials for house construction, flooring and to make underground water containers. Some of these structures can be still found today.
There is also concrete work found in Greece which dates back to 1400-1200 BC. At that time, people discovered they could add volcanic ash to it to improve the mix and allow it to set underwater.
It was also extensively used by the Romans and it's one of the reasons why so many of their structures survived to this day.
