Introduction to Concrete: Masonry and Concrete Projects for Busy People Concrete is a strong and versatile mouldable construction material. It consists of sand and aggregate like gravel mixed with water. The cement and water form a paste which coats with water and it hardens and binds the entire mixture together. This mixture can be used for constructing many projects. This eBook will introduce you to concrete, the masonry and concrete projects for busy people. It will introduce you to the tools which you need to construct these projects and will also teach you how to build a wall, fire pit, oven etc.