What materials do you need to make cement, and what are the directions for making it?
For a basic definition of cement, we consulted the nifty online version of Webster’s Dictionary: “a powder of alumina, silica, lime, iron oxide, and magnesium oxide burned together in a kiln and finely pulverized and used as an ingredient of mortar and concrete.” That’s fine for starters. Now it’s time to get serious. From Yahoo!’s commercial Concrete > Organizations category, we found a link to the Portland Cement Association, a general educational resource about the cement industry. There we learned that lime and silica make up about 85% of the mass of cement. Portland cement, the world’s most popular building material, was invented by a British stonemason in 1824, and was named for its resemblance to a type of limestone found in Dorset’s Isl
