Introduction

The deterioration and functional deficiency of existing civil infrastructure represent one of the most significant challenges facing countries in the twenty-first century. In the United States, nearly 11% of the nation’s highway bridges are presently structurally deficient and 19% are functionally obsolete. In the United Kingdom, over 10,000 concrete bridges need structural attention (Rizkalla and Hassan 2002). A substantial number of structures in Europe are more than 30 years old. While they require continual maintenance, they also require strengthening due to lack of strength, stiffness, ductility, and durability (Motavalli and Czaderski 2007).