Poured? First I’ve heard of that theory. Been watching Ancient Aliens, eh?
No, mister smart aleck, it’s from a book about, hmm, 25, 30 years ago. It’s literally the only construction method that will work given the time frame. In modern times, in South America, a small mountain was found to have gold deposits. Thousands of men with individual claims (I think they’re 12 feet square or something) dug the soil away to find bits of gold, one 40 pound bag at a time. Where the mountain was, there is now a pit. Having loose, mined materials carried up the pyramid (with or without Houdin’s internal ramp — his ramp idea works with geopolymerization, but the reverse is not the case) in bags or baskets, 40 pounds at a time, would be sustainable by a chalcolithic civilization, which they were at the time.
http://www.geopolymer.org/archaeology/pyramids/