Pyramids of Giza Made Out of Concrete

[maikeru]

Surprise, surprise. Study suggests that the ancient Egyptian pyramids were actually made out of an early form of concrete:

The Surprising Truth Behind the Construction of the Great Pyramids | LiveScience

[Boerseun]

Awesomely interesting! Good evidence for that theory, and it explains quite a lot. Seems like the "How did they lug those big stones up such an incline" question is solved by "They carried up buckets of concrete, stupid!"

[maikeru]

I still like the theory that they were made by technologically advanced aliens as flying saucer landing strips or runways.

[CraigD]

Originally Posted by Boerseun

Seems like the "How did they lug those big stones up such an incline" question is solved by "They carried up buckets of concrete, stupid!"

I get the impression from the LiveScience article that only the facing stones (many of which have been damaged and looted over the centuries) are made of concrete. No one appears to be claiming that the rough interior stones are not quarried.

So the “ropes, rollers, ramps, and sweat” construction explanation seems intact. In essence, the concrete facings of the Great Giza pyramids are a sort of very thick, very smooth, very durable stucco.

That 26th C BC Egyptian builders were excellent casters offers explanations for other mysteries I’ve read of over the years. One involves the construction of many objects found within pyramids of this and later periods, such as massive stone boxes, which were discovered to be fitted together with wood dowels. I read an account by an engineer who noted that some of the dowel holes would require tens of hours to be bored by the best modern tools. By his estimation, the hand-powered bronze drills the ancient Egyptians were assumed to have would have required decades. His conclusion was that the Egyptians had pulley-driven (though likely animal or human-powered) drills and similar "industrial" technology, approaching in many areas the 19th century state of the art.

If they were cast, making as many dowel-holes of whatever depth you wish is just a matter of positioning dowels precisely in your mold forms – not a hard trick at all. The resolves the paradox of why, if 26th century BC Egyptians could drill holes as well as 19th century westerners, their culture wasn’t also strewn with 19th century-like mass-produced goods.

[NLN]

If this turns out to be true, I'm amazed that no one was able to figure it out before. You'd think that it would be easier to tell native stone from man-made ones. Of course, this means that there must have been hundreds (thousands?) of block-forming molds used -- perhaps constructed on the spot as needed and then taken apart again. Where is the evidence for these forms? Why are there apparently no hieroglyphics of concrete block-forming left behind?

[charles brough]

Originally Posted by NLN

If this turns out to be true, I'm amazed that no one was able to figure it out before. You'd think that it would be easier to tell native stone from man-made ones. Of course, this means that there must have been hundreds (thousands?) of block-forming molds used -- perhaps constructed on the spot as needed and then taken apart again. Where is the evidence for these forms? Why are there apparently no hieroglyphics of concrete block-forming left behind?

Good questions! Also, where are the copper/brass tools they are supposed to have used to cut the stones. Apparently, they are not to be found. So, the puzzle continues . . . I remember reading the first proposal of this theory and it made a lot of sense then (20 years ago) as now. It would appear to me that, as the authors say, they used their concrete forms to build the upper and outter blocks.