Development of low cost packaged fibre optic sensors for use in reinforced concrete structures

Abstract

There is an ongoing need to measure strains in reinforced concrete structures more reliably and under a range of circumstances e.g. long term durability (such as effects of cracking and reinforcement corrosion), response to normal working loads and response under abnormal load conditions. Fibre optic sensors have considerable potential for this purpose and have the additional advantages, including of immunity to electromagnetic interference and light weight (Grattan et al, 2000). This is important in railway scenarios and particularly so when the lines are electrified. Their small size allows for easy installation. However, their use as commercial 'packaged' devices (traditionally seen as necessary to achieve adequate robustness) is limited by their high cost relative to other sensor devices such as encapsulated electric resistance strain gauges. This paper describes preliminary work to produce a cost-effective and easy-to-use technique for encapsulating fibre optic sensors in resin using 3D printing techniques to produce a robust, inexpensive 'packaged' sensor system suitable for use with concrete structures. The work done to date has shown this to be a convenient and economical way of producing multiple sensors which were suitable for both surface mounting and embedment in reinforced concrete structures. The proof-of-concept testing to which the trial packages were subjected is described in the paper and the results indicate that 3D printed packages have considerable potential for further development and use in a variety of civil engineering applications, competing well with more conventional sensor systems.

On the Use of Embedded Fiber Optic Sensors for Measuring Early-Age Strains in Concrete

“…Scott et al [ 29 ] developed a cost-effective and easy-to-use technique for encapsulating resin fiber optic sensors, using a 3D printing technique sensor system suitable for use with concrete structures for both surface mounting and embedment situations. Tests performed by the authors demonstrated the potential of the packaged sensors for strain measurement in concrete structures, but further development is still needed to assess the quality of their applicability.…”

“…Another research that used FOS to read concrete strains was developed by Sienko et al [ 29 ]. In this work, fiber optic sensors were used to investigate strains and cracks in a reinforced concrete element during a load test.…”

Application of Novel Machine Learning Techniques for Predicting the Surface Chloride Concentration in Concrete Containing Waste Material

“…The ingress movement of chloride ions in RCC structures is calculated using Fick's second law of diffusion, as shown in Equation (1). This is mostly used when designing the service life of structures located in a marine environment [16].…”

“…Reinforced concrete (RC) structures are known for their longevity and resistance, which are very valuable in civil engineering practices [ 1 ]. This includes the construction of harbor docks, marine structures, and coastal roads.…”

Fiber Optic Sensors Embedded in Textile-Reinforced Concrete for Smart Structural Health Monitoring: A Review

“…Fiber Optic Sensors (FOSs), on the other hand, have considerable potential for this purpose and have additional advantages, such as, immunity to electromagnetic interference and their light weight [ 19 ]. This is an important aspect for some civil infrastructure, i.e., railways where the lines are electrified [ 20 ]. Thus, there has been in depth research on the feasibility and deployment of FOSs for SHM purposes [ 21 , 22 , 23 ].…”