In 1979, at the second International Congress of Egyptologists, Grenoble, France, he presented two conferences. One set forth the hypothesis that the pyramid blocks were cast as concrete, instead of carved. Such a theory was greatly disruptive to the orthodox theory with its hundreds of thousand of workers taking part in this gigantic endeavor. Yet, Prof. Davidovits decided to stop momentarily his researches on this topic, concentrating his time and effort on modern technology. The carving and hoisting theory indeed raises questions that have been insufficiently answered.
Experts can only guess.
And Egyptologists must admit that the problems have not been resolved. Theories of construction are many and continue to be invented. All are based on carving and hoisting natural stone, and none solves the irreconcilable problems. The casting and packing agglomerated stone theory instantly dissolves the majority of the logistical and other problems. But I don't believe he has ever said or proved that Giza stone really is geopolymer.