Chapter 2 - Design for Durability with Galvanized Reinforcement

Abstract

This chapter presents that it is inherent in the nature of concrete as a material, and in construction as a technology, that there is no single approach that will ensure long-term concrete material stability and structural integrity when reinforced concrete (RC) structures are exposed to severely aggressive environments. The chapter provides a global design strategy—a holistic approach—incorporating a judicious integration of material properties and structural design that will give a structure it's prescribed and specified durable service life. Such a strategy will involve four distinct operations—namely, the development of a highly impermeable concrete matrix, the protection of concrete, the protection of reinforcement, and design for structural integrity. In harsh environments with rapidly changing climatic and ambient conditions, all these distinct design stages would need to be incorporated and close attention will have to be paid to all these aspects if structures are to function efficiently and satisfactorily. It discusses three distinct aspects of this steel protection technology; the need to protect steel, the basic requirements of galvanized reinforcing bars, and material and structural design implications of the use of galvanized bars. Adequate cover and good-quality concrete are essential ingredients for durability of all reinforcing bars in concrete, and this is also true for all coated bars, including galvanized, epoxy-coated and stainless clad bars. The chapter also presents extensive data to show that, under such conditions, galvanized bars can provide excellent corrosion resistance to RC structures and substantially extend their durable service life of concrete.