Monitoring of concrete shrinkage and creep using Fiber Bragg Grating sensors

The research work reported in this paper is related to a Structural Health Monitoring (SHM) Project on a bridge in Ontario, Canada. It was recommended to use Fiber Bragg Grating (FBG) sensors to measure the dynamic response of the bridge and to measure creep and shrinkage in the piers of the bridge. The random decrement method is used to determine the deterioration through the dynamic parameters of the bridge as reported by Elshafey et al. [2] and Morsy et al. [15]. The measurements of creep and shrinkage strains are based on the FBG sensors reading that presented in the current paper. This investigation was necessary to ensure the creep and shrinkage strains are accurate based on a portable lab-top windows system integration system for the FBG readings. Normally, the lab FBG integration systems are very bulky and very expensive and fixed at lab location. However, due to the recent development in the electronic industry, it was possible to use a laptop portable computer system in this investigation. The system has been found accurate compared to the lab fixed equipment and it costs fraction of the expense. The test results of the measured creep and shrinkage showed an excellent correlation of the published data on Normal Strength Concrete (NSC), High Performance Concrete (HPC) and Ultra-High Performance Concrete (UHPC) using Fiber Bragg Grating (FBG) sensors. Results show that the FBG is a valid method for studying the time-dependent properties of concrete.