Field assessment of fibre-optic Bragg grating strain sensors in the Confederation Bridge

Characterisation of carbonated Portland cement paste with optical fibre excitation Raman spectroscopy

“…As can be seen, the spectrum in Fig. 5(b) was also dominated by a sharp peak located at 1086 cm -1 , which is again due to the 1 To further compare the working capacity of these two Raman systems for characterising cementitious materials, all the bands identified by the bench-mounted Raman and the optical fibre Raman systems are summarised in Table 7, whereas the wavenumber and SNR of the 1 CO3 2-peak are compared in Table 8. Lattice vibration (LV) in vaterite From Table 7 and ii) Different signal intensity, noise level and overall SNR were identified under the bench-mounted Raman and the optical fibre excitation Raman systems.…”

“…In recent decades, structural health monitoring (SHM) with the employment of sensors has shown some success in monitoring the physical properties, such as stress and strain, of concrete structures [1,2]. However, it has been increasingly recognised that, instead of physical properties, monitoring the changes in the chemical composition of hardened cement paste in concrete is more important because this can provide an in-depth understanding on the evolution of concrete deterioration mechanisms such as chloride ingress, carbonation and sulphate attack over time, so that both the prediction of service life and the diagnosis of the causes of deterioration can be established.…”

Technology developments in structural health monitoring of large-scale bridges

“…The envisioned future for bridge health monitoring uses an array of inexpensive, spatially distributed, wirelessly powered, wirelessly networked, embedded sensing devices supporting frequent and ondemand acquisition of real-time information about the loading and environmental effects, structural characteristics and responses. Fiber optic sensors have successfully been applied for long-term structural health monitoring of largescale bridges (e.g., [45,46] among others), whereas the application of wireless sensors for bridge monitoring is still in the technology demonstration stage [43].…”

Smart Sensing Technologies for Structural Health Monitoring of Civil Engineering Structures

“…Using three 25-ton calibrated trucks to evaluate the strain level in the FRP reinforcements, the measured strains in the FRP reinforcements were less than 20 με, and strains in the steel girder were less than 120 με. Mufti et al [18] described the procedure of embedding FBG sensors in the Confederation Bridge, Canada, but no data from these sensors have been reported. In Taylor Bridge, a total of 63 FBG sensors and a total of 26 electric strain gauges were bonded to the prestressing CFRP bars to monitor the maximum strain in the reinforcement due to the applied loads.…”