This report summarizes the findings and results from a laboratory and field study on the strain distribution and crack development in 3" thick concrete panels cast on top of existing concrete pavements as a rapid rehabilitation strategy for roadways. Both fiber Bragg gratings (FBG) and Brillouin Optical Time Domain Reflectometry/Analysis (BOTDR/A) were applied and tested for their feasibility and effectiveness in distributed strain measurement and crack detection. For laboratory tests, six 6'×6" panels were cast similar to their corresponding field construction. Each was tested under both truck loads and under threepoint loads. The performance of distributed BOTDR/A strain measurements was compared with that of FBG sensors. In field study, the performance of FBG sensors was compared with that from strain gauges when the ambient temperature was measured with thermocouples. Overall, hairline to major cracks can be successfully detected with the distributed BOTDA measurements. The strain distributions measured from the FBG and BOTDR/A sensors are consistent. The FBG readings are in good agreement with those of strain gauges. Both FBG and BOTDR/A technologies are promising for pavement monitoring.
G. Chen et al., "Unbonded Portland Cement Concrete Overlay/Pavement Monitoring with Integrated Grating and Scattering Optical Fiber Sensors," Center for Transportation Infrastructure and Safety/NUTC program, Missouri University of Science and Technology, Jun 2014.
Civil, Architectural and Environmental Engineering
United States. Department of Transportation
Keywords and Phrases
Unbonded Concrete Panel; Optical Fiber Sensors; Crack Detection; Strain Distribution
Report - Technical
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