ABSTRACT
A reinforced concrete structure may be subjected to four basic types of actions: bending, axial load, shear, and torsion. Because each of the four basic actions experienced by reinforced concrete structures has been found to adhere to the fundamental principles of the mechanics of materials, a unified theory is developed encompassing bending, axial load, shear, and torsion in reinforced as well as prestressed concrete structures. The unified theory is divided into five model components based on the fundamental principles employed and the degree of adherence to the rigorous principles of mechanics of materials. This chapter presents the position of the unified theory in the field of structural engineering, then defines the five components of the unified theory and reviews the five truss models and some projections of future development. This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book.
