Fiber Optic Sensing of Prestressed-Prism-Reinforced Continuous-Composite Concrete Beams for Bridge Deck Application

This investigation involves the identification and use of a novel type of fiber optic sensor in nondestructive testing and monitoring of the deformation behavior of critical sections of structural concrete elements and transforming them into smart systems. Deformational behavior of high-performance-concrete continuous-composite beams reinforced with prestressed prisms was studied and instrumented using fiber optic Bragg grating sensors. Such elements are useful as components of continuous bridge decks where prevention of cracking in the negative moment regions is essential to maintaining the integrity of a bridge. An experimental technique using Bragg grating sensors to evaluate the behavior of the investigated elements at service load stages and the potential of this technique for on-line, real-time monitoring of existing constructed concrete structures are presented. Four continuous beams 5791 mm (19 ft) long with two equal 2743-mm (9-ft) clear spans were tested to failure. High-performance concrete with compressive strength f_c’ in excess of 90 MPa (13,000 psi) was used for both the precast prestressed prisms and the main beams cast in situ. Experimental results were compared with theoretical evaluations obtained from nonlinear analysis. Parametric study was conducted to further identify the primary variables that affected the structural performance of such composite T-sections.