Pyramid stones are made of concrete and cast in place. It's very primitive technology, which is known for few thousand years.
Pyramid stones are made of concrete and cast in place. It's very primitive technology, which is known for few thousand years.
The pair believe that the concrete method was used only for the stones on the higher levels of the Pyramids. There are some 2.5 million stone blocks on the Cheops Pyramid. The 10-tonne granite blocks at their heart were also natural, they say. The professors agree with the “Davidovits theory” that soft limestone was quarried on the damp south side of the Giza Plateau. This was then dissolved in large, Nile-fed pools until it became a watery slurry.
Lime from fireplace ash and salt were mixed in with it. The water evaporated, leaving a moist, clay-like mixture. This wet “concrete” would have been carried to the site and packed into wooden moulds where it would set hard in a few days. Mr Davidovits and his team at the Geopolymer Institute at Saint-Quentin tested the method recently, producing a large block of concrete limestone in ten days.
http://www.ce.memphis.edu/1101/interesting_stuff/pyramids_in... https://www.geopolymer.org/archaeology/pyramids/are-pyramids...
https://www.researchgate.net/publication/288698728_Evidence_...
I saw picture of cement klin (oven?, non-native speaker) in Peru, built more than thousand years ago, which looks _exactly_ like freshly build cement klin near to my home (Rivne, Ukraine), but labeled as "an ancient temple, filled with dirt".
[1]: Lea's Chemistry of Cement and Concrete