The invention relates to a flexible strip (1) for a civil engineering structure, that can extend longitudinally along a longitudinal axis and comprises at least one optical fiber (20) enabling a structure to be localized and measured in terms of deformation and/or temperature, where said optical fiber (20) is essentially arranged along the longitudinal axis and is surrounded by an at least partially reinforced thermoplastic polymeric matrix of continuous reinforcement fibers (30), essentially along the longitudinal axis, and where the mass quantity of continuous reinforcement fibers extending essentially along the longitudinal axis, WCF, is higher than, or equal to, ten times the mass quantity of optical fiber(s), WOF. The invention also relates to metrology devices and associated methods.