Vibration-Based Nondestructive Damage Detection for Concrete Plates

This research's primary objectives were first to verify a reliable structural health monitoring (SHM) experimental technique for reinforced concrete slab plates, and secondly, to introduce a special fiber Bragg grating (FBG) sensors cable system for continuous field monitoring of concrete. The particular focus was on the damage assessment, using an effective ambient vibration-based damage diagnostic technique of random decrement (RD). An investiga-tion examined the extent of damage induced by progressive static loading through a numerical RD algorithm for four concrete plate specimens: three reinforced high-strength concrete (HSC) plates with different reinforcement ratios, and one ultra-high-performance fiber-reinforced concrete (UHP-FRC) plate. The extent of damage was measured through relative changes in the natural frequency and damping ratio as dynamic parameter damage indexes, which were obtained from RD signatures at cracking, yield, and ultimate loadings. Concurrently, the behavior of the concrete slabs was examined regarding the load-deflection relationship at service and ultimate load, crack pattern, and failure modes.