A technique for embedding EFPI fiber optic strain sensors in concrete

Experiments were performed to determine suitable optic sensors in concrete. Three different encapsulation methods were considered, including, the encapsulation of sensors by liquid epoxy monomer and subsequent polymerization, the encapsulation of sensors by a pair of flat acrylic sheets, and the encapsulation by a pair of epoxy sheets. In each method, two encapsulated samples were prepared, identically embedded in concrete cylinders and tested in a universal testing machine (UTM). It was observed that epoxy sheet encapsulation results in satisfactory performance compared to the use of acrylic sheets for encapsulation. Furthermore, the epoxy sheet encapsulation showed satisfactory performance at high strain ranges.