Why a book about concrete? Because we use so much of it -- far more than any other building material. It seems only sensible to inquire as to how we can use this ubiquitous building material without undue damage to the life and landscapes that surround us. You may have heard of fly ash as an eco-friendly alternative to using portland cement in concrete, but until now there has been no easy guide to how it makes superior concrete, or to how to use it. This book isn't just for people who want to "build green" -- it's for people who want to build better concrete.