I had not heard this theory before although I did know that the Romans used concrete which seems to have stood the test for 2000 years, one example
being The Pantheon so maybe concrete goes further back in time.
Even though they are among the best-known structures on Earth, the pyramids of Egypt may still hold surprises. This spring, an MIT class is
testing a controversial theory that some of the giant blocks that make up the great pyramids of Giza may have been cast in place from concrete, rather
than quarried and moved into position.
In order to help identify blocks that were cast rather than quarried, students in the class, Materials in Human Experience (class 3.094), are
assembling a small pyramid using a combination of both kinds of material. They will then use techniques such as microscopic imagery and chemical
analysis to look for signs that might provide ways of telling the difference on samples from the Great Pyramid itself.
