Authors: C. Sousa, C. Rodrigues, J. Malveiro, R. Calçada, A. Serra Neves

The characterization of the longitudinal stress distribution along the reinforcing bars, in reinforced concrete structures, plays as important role for the development and calibration of numerical models to describe the cyclic behavior of cracked structures. The present work presents a procedure for laboratorial evaluation of strains in RC beams using arrays of optical fiber Bragg grating sensors. Each array is composed of 10 strain sensors spaced 25 mm apart, which measure the strain variation along the bar length. In this way, bond-slip effects, and the resulting variation of steel stresses with the distance to the crack section, can be determined. The experimental results are compared with numerical calculations considering constitutive models to describe the cyclic bond stress-slip relationship at the interface between the steel bar and the surrounding concrete, and the normal stress-crack opening relationship under cyclic loading

C. Sousa¹ | C. Rodrigues² | J. Malveiro¹ | R. Calçada¹ | A. Serra Neves¹
1 Departamento de Engenharia Civil, Universidade do Porto
2 Departamento de Engenharia Civil, Instituto Superior de Engenharia do Porto