Title: The Modern Arch
Description: Reinforced concrete arch bridges came into use in the United States at the end of the 19th century, quickly developed in scale and complexity, and became a standard bridge type found across the country. The earliest examples of these bridges are significant because they illustrate the development of reinforced concrete technology and contemporary design trends. However, these structures are underrecognized for their significance and many have been demolished. This thesis aims to illustrate the significance of these bridges and to highlight the preservation challenges they face. The thesis details the development of early concrete arch bridges, discusses the existing policies governing their preservation, and analyzes the effectiveness of these policies through case studies in Connecticut, New York, and New Jersey. These case study bridges vary in design, condition of preservation, ownership, and significance, yet each bridge provides insights regarding the process of preservation and its challenges.

In the analysis of these case studies, it is found that the significance of many early reinforced concrete arch bridges is not properly acknowledged, and they may be destroyed or suffer a loss of integrity as a result. These earliest reinforced concrete arch bridges are now about 120 years old and worthy of respectful attention. The insights and recommendations developed through the cases studied in this thesis are intended to help both preservation professionals and the general public evaluate other examples of this bridge type.