Fiber-Optic Sensors for Concrete Strain-Stress Measurement

TLDR: In this article, a nondestructive testing method based on fiber optics for measuring strain and stress in concrete structures in situ is presented, and two most promising techniques for concrete-structures diagnostics are demonstrated in the laboratory using concrete cylinders subjected to unconfined uniaxial compression with optical fibers embedded in a direction parallel and perpendicular to the aplied strain (load).

Abstract: The paper presents a nondestructive testing method based on fiber optics for measuring strain and stress in concrete structures in situ. When an optical fiber is embedded in concrete, and its refractive index, dimension, and/or shape are changed as a result of the surrounding matrix deformation, the characteristics of the light signal transmitted along the fiber are modified. Optical techniques capable of determining the changes in light characteristics are described. The two most promising techniques for concrete-structures diagnostics are demonstrated in the laboratory using concrete cylinders subjected to unconfined uniaxial compression with optical fibers embedded in a direction parallel and perpendicular to the aplied strain (load). Encouraging experimental results indicate that fiber-optic sensors can be a feasible tool to determine strain/stress distribution in buildings and infrastructures.