Here some links and excerpts from major English, American and German news papers
Materials Science: Concrete evidence
The scientific magazine NATURE, vol. 444, p. 793 (14 december 2006) writes in his News about the recent analysis on pyramid stones:
“Some of the massive blocks making up the great pyramids of Giza in Egypt (pictured) are not limestone, but a synthetic mix like concrete, argue materials scientists. The paper by Michel Barsoum of Drexel University in Philadelphia, Pennsylvania, and his colleagues is the latest entry in a decades-long argument. Most Egyptologists reject the idea, put forth in the mid-1980s by French chemist Joseph Davidovits, that the pyramids contain concrete. Barsoum’s team took a fresh look at 15 samples using scanning- and transmission-electron microscopes. The samples contain ratios of elements, such as calcium and magnesium, that do not exist in nearby limestone. The imaging also revealed regions of amorphous structure. Both observations suggest that other substances were added to make a concrete mix, say the authors.