New innovative methods of bridge design are being sought to increase the service life of these structure. High Performance Concrete (HPC) and Ultra-High-Performance Concrete (UHPC) utilizes a mix of high strength concrete with steel fibers to create a strong and ductile reinforced concrete mix. While not new to civil engineering construction, this material still has some uncertainty of its performance both long and short term. As a result, in-situ experimental monitoring is important to verify methods of design and the suitability of the materials. A two-span pre-stressed UHPC and HPC reinforced concrete bridge superstructure was designed at New Mexico State University (NMSU) and constructed outside of Las Cruses, New Mexico in 2017. Monitoring of the superstructure took place in January 2018 and February 2019 where multiple sensor systems were deployed to capture the behavior under controlled loading conditions. A team from the University of Texas at Tyler (UT Tyler) deployed multiple 3-D and 2-D Digital Image Correlation (DIC) sensor systems to monitor deflections and strain at various location of the girder. To the knowledge of the research team both tests are the largest simultaneous deployment of DIC systems for experimental load testing of a bridge. In DIC, the measured object is photographed with either a pair of digital cameras (for 3-D DIC) or a single digital camera (for 2-D DIC) before, during and after a load event, and a stochastic pattern marked on the object is tracked from one set of images to the next such that a full field of displacements is derived. The DIC system was successful in capturing displacements but strains were too low and not within the resolutions of the system. The testing serves as an early in-service response of the structure that can be used in comparing long-term performance of the superstructure. The results from testing indicate DIC is a powerful non-contact measurement approach to capturing in-situ displacement of highway bridges.
Date of publication
Michael Gangone, Michael McGinnis, Gokhan Saygili
Sharma, Prajwol, "IN-SITU FIELD MONITORING OF A UHPC AND HPC BRIDGE SUPERSTRUCTURE UNDER DIAGNOSTIC LOAD TESTING USING DIGITAL IMAGE CORRELATION" (2019). Civil Engineering Theses. Paper 13.