Viewing post #442892 by crowrita1

Portland cement is made by baking limestone(85%), and other minerals( clay is one of them, along with iron oxide and alumina(10%)) in an oven, or kiln. The resulting cinder is then ground to a powder. Clay is a mineral "soil", with very small particle size( a powder, actually). As mineral soils increase in particle size...next larger is silt, next sand, then it's into gravel, and from there boulders, and mountains, I guess! . Concrete is made of Portland cement, aggregate( sand, and either crushed limestone or gavel), and water. Adobe is made from clay( in a "mud' state) and either straw, or grass, mixed and baked in the sun. if you bake the adobe blocks in a kiln, you have what we call bricks( you don't need the straw then, as the kilning gives enough strength to provide tension strength). Basically, the larger the size of the particles, the less they want to clump together.that's probably more than you wanted to know, Catlin! ....Arlyn