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]

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]

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.

[Michaelangelica]

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

Personally I've often wondered about the Greeks/Athenians. They go too much right! The circumference of the earth, atoms, steam engines, computers/clocks, the roundiness of earth and that it revolved around the sun, etc etc.

Maybe even democracy?

 

Surely we can tell the difference between rocks and cement?

[cocoa]

Pyramids are one of the common spots in this world, for its uniqueness and how Egyptians made it?. As what I've learned before that pyramids are really concrete made, its every side or angle is really a concrete. That is, they made it hundreds of years...maybe.

[Michaelangelica]

Does anyone know what the recipe was?

[Turtle]

Does anyone know what the recipe was?

 

yes. :P this is from the article in the original post. >> :(

 

...According to the caller, the mysteries had actually been solved by Joseph Davidovits*, Director of the Geopolymer Institute in St. Quentin, France, more than two decades ago. Davidovits claimed that the stones of the pyramids were actually made of a very early form of concrete created using a mixture of limestone, clay, lime, and water.

 

“It was at this point in the conversation that I burst out laughing,” says Barsoum. If the pyramids were indeed cast, he says, someone should have proven it beyond a doubt by now, in this day and age, with just a few hours of electron microscopy.

 

It turned out that nobody had completely proven the theory...yet.

 

“What started as a two-hour project turned into a five-year odyssey that I undertook with one of my graduate students, Adrish Ganguly, and a colleague in France, Gilles Hug,” Barsoum says.

 

A year and a half later, after extensive scanning electron microscope (SEM) observations and other testing, Barsoum and his research group finally began to draw some conclusions about the pyramids. They found that the tiniest structures within the inner and outer casing stones were indeed consistent with a reconstituted limestone. The cement binding the limestone aggregate was either silicon dioxide (the building block of quartz) or a calcium and magnesium-rich silicate mineral.

 

The stones also had a high water content—unusual for the normally dry, natural limestone found on the Giza plateau—and the cementing phases, in both the inner and outer casing stones, were amorphous, in other words, their atoms were not arranged in a regular and periodic array. Sedimentary rocks such as limestone are seldom, if ever, amorphous.

 

The sample chemistries the researchers found do not exist anywhere in nature. “Therefore,” says Barsoum, “it’s very improbable that the outer and inner casing stones that we examined were chiseled from a natural limestone block.”

 

More startlingly, Barsoum and another of his graduate students, Aaron Sakulich, recently discovered the presence of silicon dioxide nanoscale spheres (with diameters only billionths of a meter across) in one of the samples. This discovery further confirms that these blocks are not natural limestone. ...

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

 

*see also this article on professor davidovits: >> Joseph Davidovits - Wikipedia, the free encyclopedia

[clapstyx]

"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"

 

Yes but if they were using the tools we buy from china some stupid plastic bit would break in the first half hour and they would use all thier brainpower trying to get a warranty claim out of china via some babbling indian at a call centre in downtown Bombay.

[HydrogenBond]

One thing to consider is invention is the rate limiting step. Once a simple invention, like making concrete appears, it can go viral. It is not like concrete uses a lot of ingredients. The average Joe could copy and then R&D is add his own ingredients.

 

The Egyptians had statues back then, and the royal sculptures and artist would look for new media. Instead of making clay, he tried a new blend for lighter color and more robust texture. It worked good for molding rough pieces, but did not chisel cleanly.

[maikeru]

Personally I've often wondered about the Greeks/Athenians. They go too much right! The circumference of the earth, atoms, steam engines, computers/clocks, the roundiness of earth and that it revolved around the sun, etc etc.

Maybe even democracy?

 

Surely we can tell the difference between rocks and cement?

 

So we hope. Greeks and Athenians are high on my list of clever ancient peoples too, along with the Mayans, Aztecs, Incas, and ancient Amazonian peoples.

[clapstyx]

Re clever ancients

 

I would say they must have shared and developed their ideals quite freely.

[Freddy]

Re clever ancients

 

I would say they must have shared and developed their ideals quite freely.

 

Here is another article that supports the concrete theory.

 

"Barsoum, a professor of materials engineering, said microscope, X-ray and chemical analysis of scraps of stone from the pyramids "suggest a small but significant percentage of blocks on the higher portions of the pyramids were cast" from concrete.

 

He stressed that he believes that most of the blocks in the Khufu Pyramid were carved in the manner long suggested by archaeologists. "But 10 or 20 percent were probably cast in areas where it would have been highly difficult to position blocks," he said."

 

http://www.nytimes.com/2008/04/23/world/africa/23iht-pyramid.1.12259608.html?_r=1&pagewanted=2

[Tormod]

It really makes a lot of sense. It's not the first time I've heard this, but I wouldn't put it beyond the egyptians to use whatever smart method they could conjure up.