Cracking assessment in concrete structures by distributed optical fiber

Abstract

In this paper, a method to obtain crack initiation, location and width in concrete structures subjected to bending and instrumented with an OBR system (Optical Backscattered Reflectometer) is proposed. Continuous strain data with high spatial resolution and accuracy are the main advantages of the OBR system. These characteristics make this Structural Health Monitoring (SHM) technique a useful tool in early damage detection in important structural problems. In the specific case of reinforced concrete structures, which exhibit cracks even in-service loading, the possibility to obtain strain data with high spatial resolution is a main issue. In this way, this information is of paramount importance concerning the durability and long performance and management of concrete structures.The proposed method is based on the results of a test up to failure carried out on a reinforced concrete slab. Using test data and different crack modelling criteria in concrete structures, simple non-linear finite element models were elaborated to validate its use in the localization and appraisal of the crack width in the testing slab.

Crack monitoring in reinforced concrete beams by distributed optical fiber sensors

“…Henault et al, 2012;Imai et al, 2010) as well as for fibers without any intermediate layer between the fiber and the substrate, frequently attached to the surface of the hardened concrete, see e.g. (Davis, Hoult, Bajaj, & Bentz, 2017;Regier & Hoult, 2015;Rodriguez, Casas, & Villalba, 2015a).…”

Concrete Crack Monitoring Using a Novel Strain Transfer Model for Distributed Fiber Optics Sensors

“…Moreover, the use of thin optical cables is particularly advantageous inside structures where no robust and non-intrusive crack meters or NDT techniques can do the job. Several devices have already been proposed to detect and localize cracks using Brillouin scattering [2][3][4][5][6] or Rayleigh scattering, in time domain reflectometry [7][8][9][10][11][12] or frequency domain reflectometry [13][14][15][16][17][18]. As a result, a new question arises as to the strain transfer between the host material and the optical fiber, and its potential use for the quantification of crack openings.…”

Distributed optical fibre sensors in concrete structures: Performance of bonding adhesives and influence of spatial resolution

“…Previous work has displayed the promising capabilities of this technology on the monitoring of civil engineering infrastructures …”

“…Previous work has displayed the promising capabilities of this technology on the monitoring of civil engineering infrastructures. [3][4][5][6][7][8] Nevertheless, as mentioned before, this is still a relatively new approach of this technology in the application on civil engineering infrastructures, which still presents substantial uncertainties regarding its use. Therefore, a continuous and deeper research of this topic is of vital importance for an eventually more systematically and regular use in SHM applications.…”