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Full-Text Articles in Engineering
Strain Distribution And Crack Detection In Thin Unbonded Concrete Pavement Overlays With Fully Distributed Fiber Optic Sensors, Yi Bao, Genda Chen
Strain Distribution And Crack Detection In Thin Unbonded Concrete Pavement Overlays With Fully Distributed Fiber Optic Sensors, Yi Bao, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study aims at evaluating the feasibility of strain measurement and crack detection in thin unbonded concrete pavement overlays with pulse prepump Brillouin optical time domain analysis. Single-mode optical fibers with two-layer and three-layer coatings, respectively, were applied as fully distributed sensors, their performances were compared with analytical predictions. They were successfully protected from damage during concrete casting of three full-scale concrete panels when 5 to 10-cm-thick protective mortar covers had been set for 2 h. Experimental results from three-point loading tests of the panels indicated that the strain distributions measured from the two types of sensors were in good …
Semiempirical Electromagnetic Modeling Of Crack Detection And Sizing In Cement-Based Materials Using Near-Field Microwave Methods, Jagadish Nadakuduti, Genda Chen, R. Zoughi
Semiempirical Electromagnetic Modeling Of Crack Detection And Sizing In Cement-Based Materials Using Near-Field Microwave Methods, Jagadish Nadakuduti, Genda Chen, R. Zoughi
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Detection and characterization of cracks in cement-based materials is an integral part of damage evaluation for health monitoring of civil structures. Microwave signals are able to penetrate inside of dielectric materials (e.g., cement-based materials) and are sensitive to local, physical, geometrical, and dielectric variations in a structure. This makes microwave nondestructive testing and evaluation (NDT&E) techniques suitable for inspection and health monitoring of civil structures. Near-field microwave NDT&E techniques offer the added advantage of providing high spatial resolution, requiring simple hardware that may be portable, low power, fast, real time, and robust. Additionally, these techniques are noncontact and one-sided. Besides …
Novel Distributed Cable Sensors For Detection Of Cracks In Rc Structures, Genda Chen, David Pommerenke
Novel Distributed Cable Sensors For Detection Of Cracks In Rc Structures, Genda Chen, David Pommerenke
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In this paper, the development of a fundamentally new, topology-based cable sensor design concept is summarized for crack detection in reinforced concrete (RC) structures. The sensitivity, spatial resolution, and signal loss of sensors are investigated both numerically and experimentally. Two sensors were fabricated and validated with small- and large-scale laboratory tests under different loads. Both were proven sensitive to crack of various sizes from visually undetectable to excessive, giving the location and severity of damage simultaneously. One sensor has been installed on a three-span bridge for its long-term monitoring. It is capable of recording damage that has occurred during a …