Wireless Sensor Network for Monitoring of Historic Structures under Rehabilitation

The use of a wireless sensor network (WSN) to monitor an historic structure under rehabilitation is the focus of this research. To thoroughly investigate the issue, two main objectives are addressed: the development of a reliable WSN tailored for use in historic structures, and the implementation of the monitoring system in the field to test the feasibility of the WSN and its applicability for structural health monitoring (SHM). Three field studies are undertaken in this research. The Frankford Church, an historic wooden church which required foundation replacement, is the first field study. Sensors monitor tilt of the church?s walls throughout construction. During the construction process, the entire floor of the church is removed and the tree stump foundations are replaced by concrete masonry unit (CMU) blocks and steel pedestals. The tilt in the walls is correlated to the construction process. St. Paul Lutheran, an historic masonry church with timber-framed roof, constitutes the second field study. In this structure, the foundations along the exterior walls are underpinned and the floors are removed and replaced with a floating concrete slab. Detected movements are also correlated to the construction efforts. The Johanniskirche, an historic masonry church with moisture problems, is the final field study case. Real-time and past measured WSN climate data is used to determine the most appropriate solution for the humid climate and resulting condensation problems in this structure. From these results, a moisture migration risk analysis protocol is created for use with a WSN to address condensation issues. The results of the tilt monitoring indicate that the approach is realistic to monitor tilt in the walls of historic structures. For future research, it is recommended to implement motes with higher tilt sensitivity. Also, further development of energy saving algorithms and energy harvesting methods will improve the WSN?s performance. Climate monitoring results show it is feasible to monitor climate conditions of historic structures. The moisture migration protocol provides a basis for further improvement. Implementation of this tool will help predict condensation events and prevent future damage to the historic structure.