9522734 Idriss Cracking is among the most important parameters that adversely influences the structural design and durability of concrete elements. More advanced nondestructive testing methodologies are needed for applications to bridge structures. Proper testing methodologies for early detection of cracks are either non- existence or not readily applicable to large concrete bridge systems. Research is needed for the development of embedded sensors for real-time detection, and measurement of displacements associated with crack openings and propagations. The research will examine the feasibility of using a system of optical fiber sensors for integration in an experimental full scale bridge structure. The optical fiber sensing system will be employed in detection of cracks and measurement of displacements associated with their progression. Research studies will be performed through a series of research and development activities, addressing optimization with respect to three important issues, namely, practicality, sensitivity of measurements, and capability in simultaneous detection of cracks emanating from different locations in the structure. Simultaneous measurement of displacements, at several location, will be achieved in a time domain, through interrogation of reflected optical pulses. The study will involve a series of experiments at small, as well as full scale implementation in a bridge structure. The full scale structure will be a 40 ft simple span, reinforced concrete slab, steel girder bridge. Conventional displacement measuring devices, such as strain gauges, and LVDT's will be employed in the examining the data acquired from embedded optical fibers. ***
