12-01-06, 07:55 PM #1
Pyramids poured not pushed.
This seems obvious, but here it is.
Pyramids were built with concrete rather than rocks, scientists claim
Charles Bremner, Paris
# Method used only at higher levels
# Blocks set using a limestone slurry
How the Egyptians really built a Pyramid
The Ancient Egyptians built their great Pyramids by pouring concrete into blocks high on the site rather than hauling up giant stones, according to a new Franco-American study.
The research, by materials scientists from national institutions, adds fuel to a theory that the pharaohs’ craftsmen had enough skill and materials at hand to cast the two-tonne limestone blocks that dress the Cheops and other Pyramids.
Despite mounting support from scientists, Egyptologists have rejected the concrete claim, first made in the late 1970s by Joseph Davidovits, a French chemist.
The stones, say the historians and archeologists, were all carved from nearby quarries, heaved up huge ramps and set in place by armies of workers. Some dissenters say that levers or pulleys were used, even though the wheel had not been invented at that time.
Until recently it was hard for geologists to distinguish between natural limestone and the kind that would have been made by reconstituting liquefied lime.
But according to Professor Gilles Hug, of the French National Aerospace Research Agency (Onera), and Professor Michel Barsoum, of Drexel University in Philadelphia, the covering of the great Pyramids at Giza consists of two types of stone: one from the quarries and one man-made.
“There’s no way around it. The chemistry is well and truly different,” Professor Hug told Science et Vie magazine. Their study is being published this month in the Journal of the American Ceramic Society.
The pair used X-rays, a plasma torch and electron microscopes to compare small fragments from pyramids with stone from the Toura and Maadi quarries.
They found “traces of a rapid chemical reaction which did not allow natural crystalisation . . . The reaction would be inexplicable if the stones were quarried, but perfectly comprehensible if one accepts that they were cast like concrete.”
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.
New support for their case came from Guy Demortier, a materials scientist at Namur University in Belgium. Originally a sceptic, he told the French magazine that a decade of study had made him a convert: “The three majestic Pyramids of Cheops, Khephren and Mykerinos are well and truly made from concrete stones.”
The concrete theorists also point out differences in density of the pyramid stones, which have a higher mass near the bottom and bubbles near the top, like old-style cement blocks.
Opponents of the theory dispute the scientific evidence. They also say that the diverse shapes of the stones show that moulds were not used. They add that a huge amount of limestone chalk and burnt wood would have been needed to make the concrete, while the Egyptians had the manpower to hoist all the natural stone they wanted.
The concrete theorists say that they will be unable to prove their theory conclusively until the Egyptian authorities give them access to substantial samples.
12-01-06, 08:00 PM #2
12-01-06, 08:54 PM #3
The limestone blocks are of varying shapes and sizes, as one would expect from quarried stone. Each layer (level) of stone is of a different thickness, indicating that a uniform methodolgy, such as pouring of concrete, was not in place. The granite was clearly not concrete, and was far more difficult to quarry/carve. There was a very large and extant work-force trained in quarrying stones from the earliest of the pyramids. The work-force kept getting larger and larger with each subsequent pharaoh. There are lots of depictions in paintings of gangs pulling stones over rollers.
12-01-06, 11:50 PM #4
12-02-06, 08:22 AM #5
I dont get this bit:
"Lime from fireplace ash and salt were mixed in with it."
Ash from wood etc produces potassium and sodium salts, not like. Lime is calcium carbonate. The way it has been sued in building since before the Romans is to burn it, forming calcium oxide, called quicklime. Then you slake it with water, forming a slurry of calcium hydroxide. This is then put onto the stones and the building, wher eyou wish, then as it dries it forms calcium carbonate again, over a period of months and years.
If you had cast slaked lime, teh centres of the blocks would take soemthing like centuries to dry out, if ever, because of lack of carbon dioxide getting into the centre.
SOmethings not quite right here with regards to the proposed chemistry. I need more data.
12-02-06, 11:21 AM #6
"Some dissenters say that levers or pulleys were used, even though the wheel had not been invented"
That's strange, considering that the wheel has been known to exist for at least 4000 years, and even stranger when one considers that the pyramids were being built from less than 3000 years ago and that the Egyptians also used chariots.
12-02-06, 01:25 PM #7
The pyramids are dated to over 3,000 years ago, I forget the exact date.
With regards to this Davidovits, he deals with making cement out of pulverised fuel ash from power stations. This is from coal etc, and has a very high silica and alumina content:
Class F fly ash is produced from burning anthracite and bituminous coals. This fly ash has siliceous or siliceous and aluminous material, which itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperature to form cementitious compounds (Chu et. al., 1993).
Heres a report on geopolymers, made from fly ash and silica and stuff:
The problem with regards to pyramids is that it is a setp too far from a geopolymer to the pyramids. The proposed mixture for the pyramids is missing silica and alumina. Simple grains of sand will not do, it has to be finely pulverised.
Hence, at the moment I reject teh suggestion that the Egyptions used some form of cement. I will have to see the mineraolgical data that supposedly shows this before any more judgement can be made.
12-02-06, 02:31 PM #8
Yeah I need to do tests on a sample of the stone first inorder to determine the truth of this claim!
12-15-06, 01:02 AM #9
The pyramids were almost certainly built using quarried stone blocks that were transported via sledge & rollers up ramps built up around the unfinished pyramids.
This is evident in epigraphical and archaeological remains. There are murals that depict the scenes, texts that speak of them, and unfinished public works and pyramids that incorporated ramps that still exist in Luxor. The image below shows a figure pouring liquid in front of the sledge. This was very likely oil or even just water used to lubricate the surface between the sledge and the ground. The figure seated on the limestone block is either a representation of the actual pharaoh or perhaps the scene represents a carved figure of the pharaoh being put into place. Though I think its probably a figurative representation designed to show that this was the pharaoh's project.
Not that every thing he said was entirely factual, but Herodotus tells us:
Originally Posted by Herodotus
Originally Posted by Diodorus Siculus
The pyramids built were significantly scaled down, perhaps as tall as a small house. You can read more about what is really known of pyramid construction in Lehner's The Complete Pyramids (1997, Thames and Hudson: NY). Below are some depictions of what the ramps may have looked like with the spiraling ramp being the one that was tested:
12-15-06, 01:09 AM #10
The research is legitimate even if mistaken.
The peer-reviewed paper can be found in the December 1st issue of the Journal of the American Ceramic Society.
12-15-06, 02:02 AM #11The research is legitimate even if mistaken.
I would have to read the peer-reviewed paper when I get the chance, however, to answer some of the questions that come to mind. Those include where did the researcher(s) get the samples, how were the samples chosen, and what controls were used to ensure that the samples weren't obtained from portions of the pyramids that were actually restored at some point in recent history? There has been much restoration in the pyramids of Giza and it would be difficult for all but the most knowledgeable of those working there to identify which blocks were original and which were restored. The restorations did, indeed, use geopolymer concrete.
Last edited by SkinWalker; 12-15-06 at 02:08 AM.
12-15-06, 05:13 AM #12
most importantly, nobody has asked the question of the motivation behind the wild ass new theory.
the razor tears it to bits.
12-15-06, 12:22 PM #13Still, it seems unlikely, particularly since this is just sort of thing one would have expected to be documented by Egyptians.
But, still, one shouldn't blind oneself to possible innovation.
There has been much restoration in the pyramids of Giza and it would be difficult for all but the most knowledgeable of those working there to identify which blocks were original and which were restored. The restorations did, indeed, use geopolymer concrete.
12-15-06, 12:44 PM #14
Restorations occurred in the 19th century if I'm not mistaken. It leaves one to wonder what type of concrete used then and what reason would they have to use anything other than the same materials available to the original builders.
I agree wholeheartedly, however. Innovation is vital to understanding.
12-15-06, 04:45 PM #15
Did they ever find evidence which clearly depicted the Egyptians using ANY ramp structures? I thought archaeologists had determined that some other way.
If so why does this thread exist?
12-15-06, 05:57 PM #16
All i know if i were around when they were being built i would ask "you want that where? WHY?"
Last edited by John99; 12-15-06 at 06:03 PM.
12-15-06, 11:42 PM #17
12-18-06, 06:52 PM #18
Originally Posted by TimeTravelerOriginally Posted by guthrie
12-19-06, 07:56 AM #19
So the bulk of the pyramid would still be quarried - and probably still built with the ramps / levers and whatnot that others describe - and this would STILL leave room for the cement levels, if such actually existed.
So of course there would still be evidence of quarrying - and their theory incorporates this.
12-19-06, 08:09 AM #20
I doubt this concrete theory. Like Skinwalker said, concrete may have been used in part in some places, but not for the major construction.
I can't see how they would manage to make and move the volume required. It would have been a huge process. I've been to a quarry in Egypt where blocks were cut, you can see ones that were only partially cut out, and what would have been the biggest monolith, had it not cracked during quarrying. Nobody has discovered evidence of large scale concrete production, which would require lots and lots of fuel, and lots of water. If a canal was proven to have existed, it would alleviate a logistical problem.
One of the blocks in a surrounding mastaba (I forget which, need to look it up in my guidebook) is definitely hewn, not poured, as it contains a fossilised shell, clearly visible;