Structural Monitoring of Long-span Curved Reinforced Concrete Beam-Column Frame using Distributed Fibre Optical Sensor

The paper presents the process and results of the structural health monitoring of two long-span curved reinforced concrete frames using the distributed fibre optical sensor. Optical fibres were attached to the steel reinforcing bars to obtain temperature, strain, deformation, and cracking information for the beams and columns. The temperature measurements were used to adjust the strain readings, then obtain the stress, deformation, and crack width estimations. Five measurements along the history of construction were taken with the first data set as the baseline right after casting the beams. The remaining four are measurements at 14, 28, 89, and 288 days. The measurements revealed that both ends of the long-span beams only have limited lateral movement due to the high lateral stiffness of the columns. The maximum deflections of the two beams are estimated to be 29 mm and 45 mm, respectively, which satisfy the design requirements. The maximum crack widths of both beams are estimated to be much less than 0.3 mm. The presented work demonstrates the effectiveness of distributed fibre optical sensors in monitoring long-span reinforced concrete frames with limitations to be improved in the future implementations.