Were the pyramids of Giza in Egypt partly built of concrete? A debate on the idea that has smouldered for over 20 years has been reignited by Michel Barsoum of Drexel University in Philadelphia, Pennsylvania, and two colleagues, who analysed three stone samples from the pyramid of Khufu, the largest Giza tomb.
The team found that two samples included amorphous silicon-containing material, which they say is a concrete 鈥済lue鈥� that holds the pyramid鈥檚 stone blocks together (Journal of the American Ceramic Society, vol 89, p 3788).
If true, this pushes back the first use of concrete by 2500 years. 鈥淚f there is any rock in the world like this, it hasn鈥檛 been reported in any literature I鈥檓 familiar with,鈥� Barsoum says. 鈥淭his is a concrete that has lasted 4500 years.鈥� He believes up to 20 per cent of the edifices might have been built using this material.
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Zahi Hawass, head of Egypt鈥檚 Supreme Council of Antiquities, strongly criticises the study. 鈥淲e don鈥檛 know the origin of these samples. We never gave permission for anyone to take samples,鈥� he told the news agency AFP. 鈥淭his well-worn theory keeps coming up for publicity purposes.鈥�
The idea that the Egyptians used concrete to build the pyramids was first proposed by Joseph Davidovits in 1986. Barsoum is now recreating the primitive concrete in his lab. Using only limestone, diatomaceous earth, lime and water 鈥� all readily available to ancient Egyptians 鈥� he claims to have made a compound that rivals the strongest modern concrete.
