This conservation research thesis explored the development of concrete and concrete technology used at Fort Totten by the U.S. Army Corps of Engineers (USACE), which were headquartered there. It focused on the Post-Civil War concrete fortifications (1867-1884) and the Endicott batteries (1891-1904), which underwent the eventual transition from natural cement to Portland cement concrete. The conventional view espoused by Lawry and Winslow was that when building the Endicotts, the USACE preferred Portland cement, but the US Congress preferred natural cement due to its lower cost and its proven track record throughout Third System (1816-1867) and Post-Civil War periods. This view holds that only after these early Endicotts began to prematurely deteriorate were the engineers allowed to switch to Portland cement concrete.
This thesis, therefore, examined the design differences and methods of construction for the concrete fortifications at Fort Totten built during the post-Civil War and Endicott periods. Samples of concrete were examined petrographically, using thin-section microscopy, with the aim of identifying the cement binder, the aggregate used, as well as evaluated the mix design and its performance. On-site surveys were conducted to catalogue areas of deterioration and assess contributing factors for the failure of the concrete. Archival research incorporated the records, maps and plans of the USACE, along with contemporary treatises on concrete, in order to further examine the production and experiments in concrete conducted at Fort Totten. Finally, the legacy of the Engineering School of Application at Fort Totten on the design and construction of concrete structures, including research conducted by the Essayons Club, were also examined. Therefore, Fort Totten offers an excellent opportunity to study the production and performance of two types of historic concrete, during the early period of poured concrete technology. Laboratory work for this thesis was conducted at Columbia University GSAPP’s Historic Preservation Conservation Laboratory and Highbridge Materials Consulting, Inc.