PYRAMIDS AND GEOPOLYMERS
BOOK: THE PYRAMIDS AN ENIGMA SOLVED
Prof. Joseph Davidovits
The Feasibility of the Theory
Through chemistry the task of pyramid construction was easily accomplished with the tools of the Pyramid Age. With no carving or block hoisting required, the implements needed were simply those used to lay sun-dried mud bricks: a hoe to scrape up fossil-shell limestone, a basket to transport ingredients, a trough in which to prepare reactants, a ladder, a square, a plumb line, a level, a builder’s trowel, and wooden molds (Fig.11).
These tools were found in the Sixth Dynasty pyramid of Pharaoh Pepi II. Because the molds found are only small scale models, there is no way of determining whether or not they were intended for mud bricks or large stone blocks. Pepi II’s pyramid was made of both.
Whereas the precision cutting of about 2.5 million nummulitic limestone blocks for the Great Pyramid with copper tools would be a formidable chore, copper implements are quite suitable for sawing and planing tree trunks into planks for molds. The ancient Egyptians excelled in carpentry and were the inventors of plywood. According to the Dictionaire des Techniques Archéologiques :
“ Carpentry appeared in Egypt at the end of the pre-Dynastic period, around 3500 BC, when copper tools were sufficiently developed to enable them to be used in woodworking. Throughout all epochs, the Egyptian carpenter was a remarkable craftsman. He invented all manners of preparing wood joints and made them with skill: doweling, mortises and tenons, dovetails, gluing, veneering, and marquetry. Wood being scarce in his country, he was the inventor of plywood. In a sarcophagus made during the Third Dynasty [around 2650 BC] there was actually a fragment of plywood found which was made from six layers of wood, each about four millimeters (0.15 inch) thick, held together by small flat rectangular tenons and tiny round dowels. Where two pieces had to be joined side-by-side,their edges were chamfered so as to unite exactly.
Figure 11: Implements of Sixth Dynasty are typical of Old Kingdom tools.
The grain direction in successive layers is alternated, as in modern plywood, to provide greater strength and to avoid warping. ”
As early as the First Dynasty (3200 BC), carpenters assembled planks with perfect right angles. They made round dowels of ivory or wood. The flat rectangular wooden dowel appeared during the Fourth Dynasty. A wall painting from this period illustrates the use of copper saws and the preparation of mortises and tenons using copper chisels (Fig.12). The exquisite furniture placed in the tomb of Pharaoh Khufu’s (Kheops or Cheops) mother, Queen Hetepheres, exemplifies how cleverly carpenters prepared dovetails and mortises and tenons. The magnificent funerary boat of Khufu (Kheops or Cheops), mentioned earlier, is another example of remarkable craftsmanship.
Figure 12: Mastaba from the tomb of Ti, about 2550 B.C., shows carpenters sawing planks and preparing mortises.
The Palermo Stone, fragmentary remains of royal annals, indicates that Sneferu, of the Fourth Dynasty assigned a fleet of ships to import cedar from Lebanon. The trees of Egypt are not hardwood and do not yield planks of the appropriate dimensions for molds. Egypt began to import cypress, cedar and juniper from Lebanon as early as the pre- dynastic epoch. One variety of juniper reaches a height of 20 meters (21.8 yards), excellent for making molds which must measure from 1 to 1.5 meters (1.09 to 1.64 yards) wide. Once set up, the molds were waterproofed from the inside with a thick layer of the cement itself. The cement became part of the block and can be seen at the bottom of blocks in the Great Pyramid. Wooden braces were suitable for stabilizing packed molds. Oil makes a suitable mold release, and Herodotus reported that the builders of the Great Pyramid smelled of rancid oil.
Because hard wood was so scarce, the remains of large wooden molds no longer exist. There is, however, a bas-relief that may depict a large stone block being cast.Wall paintings from the tomb of the Eighteenth Dynasty official Rekhmire (1400 BC), are precise illustrations of the technology of the New Kingdom. Although alchemical stonemaking is primarily Old Kingdom technology, we shall learn in later chapters how it was used during the New Kingdom on a smaller scale.
The molds would have been easily disassembled so that one or more faces of a block could be used as a partial mold for casting the next block, producing the close fit. One of the characteristics of geopolymeric concrete is that there is no appreciable shrinkage, and blocks do not fuse when cast directly against each other. Although it would have been impossible to achieve the close fit (as close as 0.002 inch) of the 113,000 casing stones originally on the Great Pyramid with primitive tools, such joints are easily achieved when casting geopolymeric concrete.
Once cast (probably rammed with a pestle), within hours or even less, depending on the formula and ambient temperature (minutes using today’s formulas), a block hardened. The mold was removed for re-use while a block was still relatively soft. A covering of reeds or palm leaves was probably applied to the blocks, affording an optimum amount of ventilation. This was required to harden (carbonate) the lime and protect the blocks from becoming brittle from evaporation. When the covering was removed, the blocks continued to harden in the sunlight, the heat accelerating setting.
As statues and sarcophagi were produced, finishing touches would have been made with copper tools during the early stages of setting. I have observed marks on core masonry of the Great Pyramid unlike those made with a chisel. Some appear to be impressions made by reeds. I also noticed long, sweeping impressions that fan out exactly like a palm leaf. Using a microscope, I was clearly able to see wood-grain impressions on a sample from the ascending passageway of the Great Pyramid.
It would be impossible for such an enormous cement industry to have left no traces of its existence, but those traces would never be recognized by anyone unaware of this technology. The most obvious traces are the tremendous quantities of minerals excavated from the Sinai mines, blue minerals such as turquoise and chrysocolla, generically known as mafkat during the Old Kingdom (Fig.13). Egyptologists are well aware of the industrial quantities of mafkat mined in the Sinai, but they cannot account for its consumption in such enormous quantities.
The mining expeditions of the pharaohs correspond exactly with the construction of the pyramids. Pyramid- building pharaohs are depicted in large reliefs in the cliff faces at the Sinai mines, where they are shown protecting mineral deposits from invading bedouins. There is no doubt about what was sought. Expeditions led by the archaeologist Beno Rothenberg (1967-1972), demonstrate that mineral veins containing turquoise and chrysocolla had been primitively excavated, whereas veins of copper carbonate ore were left unexcavated .
The most basic product to any cement industry is lime (CaO). To produce lime, limestone or dolomite was calcined in kilns. No distinction was made between limestone, dolomite, and magnesite, each a white stone yielding different limes and, therefore, different qualities of cement. It is well established archaeologically that the production of lime itself is the oldest industrial process of mankind, dating back at least 10,000 years. Lime mortar in the ruins of Jericho, in the Jordan valley is still intact after 9,000 years. Some wood and plant ashes contain a very high amount of lime (between 50 and 70 per cent by weight of CaO). These ashes could have been used for producing cements or mortars.
Figure 13: Fifth Dynasty stele on wall of Sinai mines shows the pharaoh Sahure symbolically smiting an intruder.
Herodotus reported that canals once connected the Great Pyramid to the Nile River. Egyptologists suggest that if these canals existed at the site, they were used to transport casing blocks from Tura, across the river. How would a canal serve the cement industry? A canal makes an ideal reaction basin for the on-site production of enormous quantities of cement.
I can envision two methods for the on-site production of the cement. One would entail placing suitable quantities of natron and lime (calcined limestone or plant ash) in a dry canal. Nile mud (Clay + silt) or the local Tafla, and water, could easily have been captured in the canal during the annual flood period. The water dissolved the natron and put the lime in suspension, forming caustic soda. Caustic soda reacted with the clay to produce a triple alumino-silicate of sodium, calcium, and magnesium. When the water evaporated, an activated substance would remain. The addition of siliceous minerals and another quantity of natron and lime produced a silico-aluminate, resulting in a basic geopolymeric cement. Other products were added, and, if necessary, the material could be stored. The resulting cement would have been used to agglomerate loose limestone rubbles and chunks, yielding reconstituted limestone blocks.
Another method is even easier and is possible due to the nature of the Giza limestone.
The Giza Plateau is an outcrop of the Middle Eocene Mokattam Formation (Fig. 14). A second outcrop of the Upper Eocene Maadi Formation borders the Pyramids Plateau on the South-South West. A large sandy wadi separates the Mokattam Formation from the Maadi Formation, created by the South-East dip of the Mokattam Formation (see on the general map of the Giza Plateau in Appendix 2). The North side of the wadi, or the southern line of the Mokattam Formation outcrop, and the South side of the wadi, or the northern line of the Maadi Formation outcrop, where both Formations dip into the wadi, were extensively quarried during the erection of the Giza pyramids.
Figure 14: Simplified NNW-SSE cross-section of the Giza Plateau. The soft-marly limestone bed that was extensively quarried (Sphinx, Wadi quarries) is sandwiched between two hard-grey limestone beds.
According to the geologist Aigner  and the egyptologist Lehner , the original ground surface of the Mokattam Formation that constitutes the basement of the pyramids,is made of a very hard and massive limestone bank of the nummulite type. On the other hand, the outcrop that dips into the wadi, where the quarries are located, consists of softer thickly bedded nummulite layers (see in Fig. 14 the location of the quarries, and also the trench around the Sphinx) with a relative high amount of clay. Concurring to the traditional carving theory, Lehner states “ ... the builders took advantage of the thickly bedded softer limestones of the south part of the Mokattam Formation, while founding the pyramids on the hard nummulite bank to the north...” 
Lehner postulates that the builders did not use the nearby hard limestone but favored the softer material. In other words, Lehner’s remark suggests that quarrying and carving the hard Mokattam limestone would have required more labor than the transport of the softer material from the wadi upwards to the pyramid plateau. This raises the question that has not been tackled by egyptology so far, namely why did the Khufu (Kheops or Cheops), Khafra (Khefren or Chephren) and Menkure (Mykerinos) architects refrain from using the limestone located up hill, nearby on the west, taking advantage of the natural inclination of the plateau, and the ease of transport? Why did they select the limestone from the wadi edges, downhill, with the supplementary burden of having to carry the blocks to a 40-50 meter height upwards on long ramps, in opposition to traditional quarrying methods? In general, during antiquity, quarries where chosen because of the ease with which the blocks could be transported, downwards, from the top of the hill down to the valley. The Aswan granite quarries, the Silsilis sandstone quarries, south of Thebes, or even the Tourah quarries located on the opposite side of the Nile Valley, in front of the Giza Plateau, are typical examples for this theorem.
The agglomeration theory provides a good answer to this issue, namely:
a) - the hard limestone nearby the basement is not suitable for the production of agglomerated blocks because it does not disaggregate easily in water;
b) - on the other hand, the softer marly limestone of the wadi edges is a suitable raw material for agglomerated limestone blocks because part of it disaggregates in water, within a short period of time. The disaggregated muddy limestone (including the fossil- shells) would be further mixed with other limestone aggregates, lime and zeolite-forming materials such as kaolin clay, silt, and the Egyptian salt natron (sodium carbonate).
In October 1991, during the shooting of the TV production “ This Old Pyramid ” by NOVA, aired on the American PBS network on September 1992, I had the opportunity to present this unique property of the Giza limestone. A chunk of limestone taken in the Wadi quarry and soaked in water was very easily disaggregated within 24 hours, leaving the nummulites and the clay gently separated from each other, whereas a chunk of the hard Mokattam limestone did not disintegrate at all (see for details in Appendix 2, the Giza Plateau Circuit).
The vast amount of limestone rubble required to make pyramid blocks was easily obtained.Water,probably brought as close as possible by canal, was used to flood the soft marly limestone of the Wadi quarries to saturate it for easy disaggregation. The body of the Great Sphinx was sculpted as muddy limestone rubble was scooped into baskets for use in pyramid blocks. Men wading in wet, muddy limestone while working in the desert heat makes more sense than men banging away at quarries in a hot, dusty desert, as called for by the accepted theory. By agglomerating stone, a better building material resulted because the blocks of the Great Pyramid are more strongly adhered than is the natural bedrock.
It is assumed that the head of the Sphinx was carved in an isolated knoll belonging to the upper weathering resistant hard-grey limestone Mokkatam layer. It brilliantly withstood 4,500 years of harsh weathering conditions. The Sphinx body is the remains of stone excavation in the softer marly layers (Fig. 15). It is assumed that the quarried stone material was used in the making of the Khafra (Khefren or Chephren) Valley Temple as well as for the Sphinx Temple. For certain experts, the strikingly obvious degradation of the Sphinx body would have resulted from “ erosion due to rain and flooding ”, i.e. disaggregation through water soaking. It has been subject to intensive restoration work during the last decades and also during Antiquity. Although it was for thousand years covered with sand and therefore protected against weathering, it underwent severe degradation. The differential water erosion has sculpted 7 sequences of projected and recessed layers. In order to explain what causes the degradation of the rock, L. Gauri made a thorough petrographic and chemical analysis of the six layers featured in Fig. 15. He measured the content of the water-soluble salts and of the non-carbonate clastic materials (clays, silt and sand). These elements - water-soluble salts plus clastic - are sensitive to water. They either become soluble (the salts) or expand when wet (the clay and the silt). I called them water- sensitive parts in Fig. 15. The amount of water-sensitive parts, expressed as weight percent of stone, is strikingly very high . The soft marly limestone of the Sphinx body is wide spread in the pharaonic Wadi quarries.A similar analysis of the equivalent layers has not been carried out so far. However, it is reasonable to assume that these limestones do contain the same range of water-sensitive parts.
Figure 15: North-South vertical profile of the front of the Sphinx. Layers #1 to #6 analyzed by L. Gauri  and amount of water- sensitive parts (salt + clastic material) for each layer.
Today, civil engineers often use the ASTM D4843 Code to evaluate the water disaggregating long-term behavior of building materials. A procedure adapted from ASTM D4843 requires that the stone be soaked for 24 hours in water, then dried out at 60°C (140°F) for 23 hours, followed by a 1 hour rest at room temperature. If, after this first cycle, the stone or the concrete remains intact, it is subjected to a second and more cycles, until it disintegrates. The 60°C (140°F) drying temperature is relevant for temperatures reached during summer time in the quarries at Giza (in the sun).
Modern Geopolymeric concretes do not disintegrate even after more than 300 cycles. As for the soft natural marly limestone of the Sphinx body, I expect that only 1 to 3 cycles would be necessary. The ancient Egyptians could have installed soaking/reaction ponds at the bottom of the quarries.These ponds would have been flooded then followed by a drying period and flooded again, in order to achieve the appropriate disaggregation. Chunks that do not disintegrate easily (dependent on the water-sensitive parts amount) would be packed into the muddy limestone matrix.
The kaolinitic limestone requires only the addition of lime (calcined limestone or plant ash), natron, and water for a geopolymeric reaction to occur. The landscape is also scattered with considerable quantities of loose shells, camites, strombites, turbinites, helicites, and especially nummulites. In ancient times there were hills of loose shells at Giza. The Greek geographer Strabo (64 BC) observed them :
“ We cannot allow ourselves to remain silent on one thing that we saw at the pyramids, namely, the heaps of small stone chips in front of these monuments.There we find pieces,which,from their shape and size, resemble lentils. Sometimes they even look like half-threshed seeds. It is claimed that they are the petrified remains of the food of the workers but this is most unlikely, for we too have a hill at home set in the middle of a plain which is filled with small calcareous tuffs similar to lentils. ”
The more loose material naturally present, the less rubble excavation required. Loose material remaining at the site today is incorrectly assumed to be debris from stonecutting.
Agglomerating stone is far, far easier than cutting and hoisting massive blocks. To imagine the difficulty of building a pyramid by way of the accepted theory, one needs only to see how difficult it is to destroy even a small pyramid. It is much easier to destroy than to create almost anything, and Abd el-Latif (AD 1161-1231), a physician of Baghdad, described the difficulty encountered by a team that set out to destroy the Third Pyramid of Giza, which is only seven percent of the volume of the Great Pyramid :
“ When Melic Alaziz Othman Ben Yussuf succeeded his father, he allowed himself to be persuaded by several persons of his court, people devoid of common sense, to demolish certain pyramids.They started with the red pyramid,which is the third of the Great Pyramids and the least considerable. The sultan sent his diggers, miners, and quarrymen, under the command of several of the principal officers and emirs of this court, and gave them the order to destroy it.
To carry out their orders they set up a camp near the pyramid.There they assembled a large number of workers and housed them at great expense. They stayed for eight entire months with everyone doing his allotted task, removing, day after day with the expenditure of all his force, one or two stones. Some would push from the top with wedges and levers while others pulled from the bottom with cords and ropes. When one of the stones eventually fell it made an appalling noise, which could be heard from a great distance and shook the ground and made the mountains tremble.
In falling, it became embedded in the sand and pulling it out required great effort.They forced in wedges,thus splitting the stones into several pieces, then they loaded each piece onto a chariot and pulled it on foot to the mountain a short distance away where it was discarded.
After having camped for a long time and using all of their money and strength, their resolution and courage diminished daily. They were shamefully obliged to abandon their work. Far from obtaining the success for which they had hoped, all that they did was damage the pyramid and demonstrate their weakness and lack of power.This occurred in the year 593 [AD 1196]. Today, if one looks at the stones that were discarded, one has the impression that the pyramid must have been completely destroyed. But if one glances at the pyramid itself, one sees that it has undergone no degradation and that on just one side part of the casing stone has become detached. ”
Casting pyramid blocks in situ greatly simplified matters of logistics, enabling the construction of the Great Pyramid without doubling or tripling the life span of the pharaohs. Instead of 100,000 workers per year at Giza as called for by the accepted theory, as few as 1,400 workers could carry enough material to build the Great Pyramid in twenty years based on the following calculation: In Cambodia, during the Khmer revolution in 1976, men each carried about 3 cubic meters (3.9 cubic yards) per day to construct dams. One man, therefore, in one day can carry enough material to produce a block weighing from four to six tons. This would provide for 1,400 blocks set per day the number reported by Herodotus. The number of men required, of course, depended on how many days were worked, which might depend on how many religious holidays were celebrated (see for details in Table I).
Assuming that each man carried one basket per hour and worked about three months a year, or perhaps 100 days, the maximum number of carriers needed for a twenty-year period was 2,352, for fifteen years, 3,136 workers; and for ten years, 4,704 workers. Assuming that each excavator was attended by three carriers and one stone caster, then three carriers represented five men at work. This would place between 1,000 and 3,000 men on the work site during a three- month work period per year, or 400 to 1,000 during a ten- month-per-year work period, in order to complete the Great Pyramid in fifteen to twenty years.
Men could easily have carried one 22.5 kilogram (50- pound) basket every fifteen minutes to the base of the pyramid, one basket every thirty minutes to the middle, and one basket to the top of the pyramid on a ramp every hour. If a basket contained 0.3 cubic meter (0.039 cubic yard), then per day each man could have carried: one basket in fifteen minutes for a total of 1.42 cubic meters (1.87 cubic yards) or one basket every thirty minutes for a total of 0.71 cubic meter (0.94 cubic yard) or one basket per sixty minutes for a total of 0.36 cubic meter (0.47 cubic yard).
Additional workers were required for mining, transporting and crushing minerals, gathering natron, oil, wood, and other necessary products, preparing ingredients, digging canals, carrying water, making tools and molds, providing food and other personal needs, and performing miscellaneous chores. This might raise the total of men required by an additional few hundred. Total figures allow for freedom to maneuver at the work site and are considerably more reasonable than the 100,000 men per year at the site called for by the standard theory. The casting theory is quite feasible and easily settles problems of logistics.
The objections to my theory
In this chapter we focussed on the two different limestone outcrops of the Mokattam Formation: a hard grey superior bed on which the pyramids are founded, and a soft yellowish (with clay beds) where the pyramids core materials were extracted. Notwithstanding the basic and visible geological knowledge on the two different outcrops within very close range of the monuments, the American geologists Harrell and Penrod challenged the casting and packing theory. In a paper published in Journal of Geological Education in 1993, they state:
“ ...Our objection to the geopolymeric process [agglomerated stone process] has to do with disaggregating limestone by soaking it in water - it does not work! We soaked the Mokattam limestones whose composition is given in Table 1 for seven weeks and after this time the samples were just as hard and solid as the day we first immersed them.... ” .
They never mentioned noticing any difference between the pyramid blocks and the hard Mokattam Formation that constitutes the surrounding plateau. Harrell and Penrod, who published on ancient Egyptian limestone quarries, ignored the presence of the two different outcrops. They relied only on the generic denomination of the Giza Pyramids bedrock, namely the name Mokattam Formation. Mokattam is the name of a Cairo suburb in the vicinity of the Citadel, made of hard limestone. The quarry at Gebel Mokattam supplies squared stones for the Cairo monuments. In the cited Table 1 of their publication, Harrell and Penrod provide the location of their tested samples, namely: Gebel Mokattam, Tura and Masera. There is no mention of any Giza sample.
For their demonstration, Harrell and Penrod deliberately took hard Mokattam limestone instead of the soft material from the wadi quarries or the Sphinx trench. In addition, the soaked sample did not come from the Giza Pyramids site at all. These ancient Egyptian quarries specialists ironically collected this piece of hard limestone from the modern quarry behind the Citadel on Gebel Mokattam, Cairo, 20 km (15 miles) east of the Giza Pyramids, on the other side of the Nile.
Other individuals who published statements against the cast and packing theory, made the same mistake than Harrell and Penrod did. For example, Moores states in a Letter to the Editors published in Concrete International :
“ ...In October 1987 I was a member of the National Geographic sponsored team that non-destructively revealed the entombed second wooden ship of Khufu (Kheops or Cheops). I designed and operated the drilling system that obtained air samples and photographs of the pit interior [hard Mokattam Formation].... I have had a chunk of nummulitic limestone, that I personally detached from the Giza plateau, soaking in water for five months now,and it exhibits no change in hardness... ”
Moores soaked in water a chunk of limestone for a long period of time, which he removed from the hard Mokattam Formation, near the Khufu (Kheops or Cheops) Pyramid base, not from the soft formation(wadi quarries or Sphinx trench), where it is agreed that the bulk of the stony material is coming from.
Two other American geologists, R. Folk and D. Campbell, vigorously challenged the theory essentially in publications that do not have the “ Peer review ” system and therefore were not edited, such as Journal of Geological Education or The Epigraphic Society Occasional Papers . There are several statements made by Folk/Campbell in these papers that demonstrate their lack of knowledge on the geological uniqueness of the Giza Plateau.Yet,they wrote with arrogance:
“ ...we feel it is the duty of professional geologist to expose this egregiously absurd archeological theory before it becomes part of entrenched pseudoscience... We believe that had Davidovits had any understanding of basic geologic principles and understood the implications of simple geological evidence at Giza, he would have realized that this geopolymer theory had no basis in fact....We have also shown how geologic commonsense can destroy archaeological quackery, but not, unfortunately, before it has enjoyed widespread publicity among the gullible and sensation- minded.... The geopolymer theory is defunct; we still remain in awe of the enigma of Egyptian skill and engineering. ”
They did not study the soft marly limestone bed and its peculiar property, at all:
“ ... A fundamental and obvious objection to the geopolymer theory is that, had the Egyptians wanted to make “ permastone ”, why would they have gone to the excessive labor of crushing limestone and gluing back together when it would have been much easier to use the abundant, nearby, loose desert quartz sand that would have surely made a more homogeneous concrete... ”
The theory never states that the limestone has to be crushed. It is obvious that Folk and Campbell did not understand the feasibility of the system based on water disaggregation. The use of sand would have required an astronomically high amount of artificial geopolymeric cement. The ancient Egyptians used this technique to manufacture their first artificial stone for statuettes 5,600 years ago. See for more details Appendix I, the Alchemical Inventions. The reason why it was not used for pyramid construction will become obvious in the next chapters.