A considerable proportion of highway bridges in the US, are made of reinforced concrete. Since there is a need to detect and recuperate the condition of the bridge structures numerous innovative non-destructive testing (NDT) techniques have come into the forefront. Of the many available technologies, acoustic emission (AE) monitoring has been the most popular passive non-destructive technique used on highway bridges. Usually AE monitoring is used to obtain qualitative results by observing the trends of the conventional AE parameters recorded by the data acquisition system. In this book, damage is quantified by applying the intensity analysis technique to conventional AE parameters generated from reinforced concrete members subjected to certain loads.