[QUOTE=thomas;49242]You don’t have to if you are pushing it along the ground. If dirt was piled around the pyramid as it was being built, then the blocks were always pushed up an incline and pushed into place and not lifted by a crane-like device.[/QUOTE]
You seem to be alluding to Davidovits theory. From the wikilink I cited above:
Limestone concrete hypothesis
Materials scientist Joseph Davidovits has claimed that the blocks of the pyramid are not carved stone, but mostly a form of limestone concrete and that they were “cast” as with modern concrete.[36] According to this hypothesis, soft limestone with a high kaolinite content was quarried in the wadi on the south of the Giza Plateau. The limestone was then dissolved in large, Nile-fed pools until it became a watery slurry. Lime (found in the ash of cooking fires) and natron (also used by the Egyptians in mummification) was mixed in. The pools were then left to evaporate, leaving behind a moist, clay-like mixture. This wet “concrete” would be carried to the construction site where it would be packed into reusable wooden moulds and in a few days would undergo a chemical reaction similar to the “setting” of concrete. New blocks, he suggests, could be cast in place, on top of and pressed against the old blocks. Proof-of-concept tests using similar compounds were carried out at a geopolymer institute in northern France and it was found that a crew of five to ten, working with simple hand tools, could agglomerate a structure of five, 1.3- to 4.5-ton blocks in a couple of weeks.[37] He also claims that the Famine Stele, along with other hieroglyphic texts, describe the technology of stone agglomeration.
Davidovits’ method is not accepted by the academic mainstream. His method does not explain the granite stones, weighing well over 10 tons, above the “King’s Chamber”, which he agrees were carved. Geologists have carefully scrutinized Davidovits’ suggested technique and concluded his came from natural limestone quarried in the Mokattam Formation.[38] However, Davidovits alleges that the bulk of soft limestone came from the same natural Mokkatam Formation quarries found by geologists, and insists that ancient Egyptians used the soft marly layer instead of the hard one to re-agglomerate stones.
Davidovits’ hypothesis recently gained support from Michel Barsoum, a materials science researcher.[39] Michel Barsoum and his colleagues at Drexel University published their findings supporting Davidovits’ hypothesis in the Journal of the American Ceramic Society in 2006. Utilizing scanning electron microscopy, they discovered mineral compounds and air bubbles in samples of the limestone pyramid blocks that do not occur in natural limestone.[40]
Dipayan Jana, a petrographer, made a presentation to the ICMA (International Cement Microscopy Association) in 2007[41] and gave a paper[42] in which he discusses Davidovits’ and Barsoum’s work and concludes “we are far from accepting even as a remote possibility of a ?manmade? origin of pyramid stones.”
Again this theory too fails. There are obvious 10+ ton carved granite blocks in the pyramids several stories up that were obviously not “dirt” These 10+ ton blocks were transported over several miles and then lifted several stories in height. How is this possible without a crane?
I did pure mechanics in A level maths and studied A level physics, but that is a distant memory.