Mr. Zahi Hawass dismissed Davidovits’ theory about the construction of the pyramids. This theory was put forward in the 1980s and postulated that the blocks of the Great Pyramid are not carved stone, but a form of limestone concrete. Mr. Hawass added that there are no scientific references to support this theoretical study.

Here's this famous theory: In a new study, a Franco-American team found out that the ancient Egyptians built the great Pyramids by pouring concrete into blocks.
The theory that the giant stone blocks would have been made at high points on the site rather than being hauled upwards was first formulated by French chemist Joseph Davidovits but has been rejected by Egyptologists.
The theory sustains that parts of the pyramids were constructed using natural limestone while other parts were man-made by reconstituting liquefied lime.
The researchers used X-rays, plasma torch and electron microscopes to compare the composition of the stones. French Professor Gilles Hug, from the Office of National Aerospatial Studies and Research, and Egyptian-born Michel Barsoum, a professor at Philadelphia's Drexel University, analyzed the mineralogy of samples from the Giza pyramids. "Examination of the stone shows they could have been made from a kind of early concrete and poured into blocks." they said.
They might have discovered what would be the oldest known occurrence of concrete, explaining in part the mystery of how the Egyptians were able to erect such colossal structures. "The sophistication and endurance of this ancient concrete technology is simply astounding," they added.

But Egypt's antiquities minister Zahi Hawass strongly rejects the new studies.
"It was limestone, it's been studied before by hundreds of chemists," Hawass, who heads the Supreme Council of Antiquities.
"They're made from solid blocks of quarried limestone. We don't know the origin of these samples... We certainly never gave permission for anyone to take samples," he said.
Mark Lehner, a leading Egyptologist, also looks with caution at the new theory. "All studies of the stone have shown they are made mostly from limestone but also from basalt and granite mined in the region." "Where did these samples come from is the first important question," he told. "How did the French take samples for their tests without the Egyptians' permission?"


MIT supports Davidovits’ Pyramid theory

And the abstract from the Journal of the American Ceramic Society (1): How the Great Pyramids of Giza were built has remained an enduring mystery. In the mid-1980s, Davidovits proposed that the pyramids were cast in situ using granular limestone aggregate and an alkali alumino-silicate-based binder. Hard evidence for this idea, however, remained elusive. Using primarily scanning and transmission electron microscopy, we compared a number of pyramid limestone samples with six different limestone samples from their vicinity. The pyramid samples contained microconstituents (μc's) with appreciable amounts of Si in combination with elements, such as Ca and Mg, in ratios that do not exist in any of the potential limestone sources. The intimate proximity of the μc's suggests that at some time these elements had been together in a solution. Furthermore, between the natural limestone aggregates, the μc's with chemistries reminiscent of calcite and dolomite—not known to hydrate in nature—were hydrated. The ubiquity of Si and the presence of submicron silica-based spheres in some of the micrographs strongly suggest that the solution was basic. Transmission electron microscope confirmed that some of these Si-containing μc's were either amorphous or nanocrystalline, which is consistent with a relatively rapid precipitation reaction. The sophistication and endurance of this ancient concrete technology is simply astounding.


Personally, I think that Mr. Hawass is quite right. Right from the start, I was astonished that no one had the idea to cut these famous stones into strips, and then to submit these strips to a microscopic analysis. In just a few hours, by using this technique one gets a clear and precise diagnostic about the artificiality or non-artificiality of any mineral matter.

Additional information:
La Nouvelle Histoire des pyramides, Joseph Davidovits, Ed. J.C. Godefroy, Paris, (oct. 2004) ; Ils ont bâti les pyramides, Joseph Davidovits, Ed. J.C. Godefroy, Paris (sept. 2002) ; (1) Barsoum, M. W., Ganguly, A. & Hug, G. (2006), Microstructural Evidence of Reconstituted Limestone Blocks in the Great Pyramids of Egypt, Journal of the American Ceramic Society 89 (12), 3788- 3796.

Not sure I clearly understand your position. Do you think the stones are carved or cast?

The pyramid of Cheops was made from solid blocks of quarried limestone. Like Mr. Hawass said, it has been proved by several chemical analyses.

Even if stones were cast on the site (or near it), they would have to be hoisted up and put up in place. In other words, Davidovits’ theory explained the transport but not the construction in itself. I’m not an architect or a bricklayer, but I think that casting stones as construction progressed is not realistic. It would have taken too much time. There were readily available natural stones close to the site; there were enough manpower to carry them, and enough workers’ guilds of specialised craftsmen to cut them. Saving of time and energy would have to be small. Besides, how long reconstructed stones last is perfectly known. There is a clear difference in the geological structure between cast stones and natural stones. Notably, the presence of zooliths within the natural stone. Taking a core sample is not even necessary. To determine the nature of the mineral matter, all you have to do is to take out a chip from the outer part of the stone.

Do you think it possible that any were cast? I lean towards cut stone as well.

Do you think it possible that any were cast?

This notion requires that some blocks show signs of casting.

But this is not the case, as all core blocks show no signs of casting at all (that is – no signs of the shuttering wood).

Mr. Hawass is quite right. And in view of what can be observed in the field, I have to agree with him.

Love you posts. Find them fascinating.

Do you think the strange statue at Tiahuanacu has some unusual construction process. This one aways seemed so different from anything anywhere else to me.

http://www.atlantisquest.com/prehistcity.html

Well, it’s not my domain of expertise. And thus I will have to do some research.

Meanwhile, perhaps Vet () will have something to say about this… Another thing – maybe we can start a new thread as this one is more focused on Egypt and especially Davidovits’ proposal about the construction of the Giza pyramids. What do you think guys?

Just three points before starting a new thread on Tiawanaku.

One. Some objects made with iron have been found in Predynastic and/or Old Kingdom times, but these objects were very small and looked like pearls and were made out of meteoritic iron. They were certainly not iron-made tools. (The iron blade that was found in the pyramid of Cheops is now considered as an intrusive find, as this blade dates from more recent times.) So there was no possibility for the ancient Egyptians to have used iron tools in the construction of the Giza pyramids. Without iron available, there was also no possibility for them to reinforce their “cements”. And this point is very important because it was the only way for the “cements” to support the massive weight and size of the pyramids.

Two. There were no “cements”, only mortars. The first use of mortar in Egypt is seen in Dahshūr, at the Rhomboidal Pyramid. It was a gypsotic mortar (a gypsum-based mortar – šd n bzn). To make mortar gypsum has to become plaster, to do that you need to burn the gypsum and get the temperature right. If you don’t burn it right, then the mortar will not constitute itself, you’ll get a weak mortar, a mortar that won’t hold. If you go to Dahshūr, you will see how they tried out the new procedure; you’ll see their mistakes as they were trying to get the temperature right. So, throughout the Old Kingdom and beyond, Egyptians used mortars. Through time various types of mortars came in use, but they were only mortars. Now, a question: if the Egyptians invented the technique described by Davidovits why did they keep on using mortars?

Three. The quarries are still there, for all to see. There are quarries close to the pyramids of Kh‛jf-R‛ (Khafre), and of Khwjf-wj (Khufu). And what do we see in the quarries? The leftovers parts of the removed limestone blocks.