Fluorescence Characteristic Analysis for Discriminating Fibers in Cementitious Composites

Abstract

This paper investigated the fluorescence properties of Polyvinyl Alcohol (PVA) fibers, Polyethylene Terephthalate (PET) fibers, Polyethylene (PE) fibers, and a cement-based matrix by using a spectrofluorometer. Optimal excitation and emission filters were also proposed to discriminate each synthetic fiber in the hybrid Engineered Cementitious Composite (ECC) by a multispectral fluorescence-imaging model and a Linear Discriminant Analysis (LDA). The experimental test results showed that the PVA fiber, PET fiber, and PE fiber used in the hybrid ECC had a unique fluorescence characteristic with a peak. On the other hand, the cement-based matrix showed a little fluorescence intensity. The optimal excitation and emission filters of a multispectral imaging system for detecting fibers in the hybrid ECC are presented here as continuous forms. The selective optimum excitation and emission wavelengths that showed maximum relative transmission are 360-389 nm, 400-445 nm, 360-390 nm, and 360-389 nm for the PVA-PET, PVA-PE, PET-PE, and PVA-PET-PE fiber reinforced cementitious composites, respectively.