Analysis of Thermal Behavior of Prestressed “Double T” Beam Made of Sustainable Carbon-Capturing Concrete

The environmental thermal effects have a great influence on the structural behavior, while the Fiber Bragg grating (FBG) sensors used in the structural health monitoring (SHM) systems require thermal compensation. This paper presents a preliminary study on the thermal behavior of the prestressed double-T slab at the top floor of the Stadium Drive Garage at Princeton University. Embedded long-gauge strain and temperature sensors, based on FBGs, were employed to monitor the structural responses of the slab over a two-year period. The study aims to assess the temperature-strain relationship of the double-T slab with complex geometries and evaluate the long-term performance of sustainable carbon-capturing concrete, the material used in the construction of the garage. To enable the application of thermal compensation techniques, the calculations of the coefficient of thermal relation between the strain and temperature using measurement data from different time periods are carried out with the implementation of the mean thermal gradient (MeLG) method. Analysis reveals relatively stable values of the coefficient of thermal relation over the monitoring period. The findings of this study have important implications for understanding structural thermal behavior with complex geometries and new sustainable materials, and contribute to ongoing efforts to improve the resilience and sustainability of civil infrastructure.