Employment of optical fibers for RC bond-slip characterization

Some features as workability, high durability and low cost of production have contributed for reinforced concrete (RC) be largely used worldwide. However, environmental actions and the natural material decaying are the most common processes that contribute for the loss of the physical-mechanical properties of the RC structures. When the bond between the concrete and the reinforcing rebar are affected, the results can be extremely dramatic and unpredicted. In this work, an optical fiber device for the monitoring of the bond-slip of old RC structures, where less intrusive techniques need to be considered, is proposed and tested. The sensor developed is based on the fiber Bragg grating (FBG) technology, inscribed in silica optical fiber. A pull-out test was carried out in a RC specimen, following the recommendations of the Annex D of the EN 10080. The results showed that the bond-slip optical sensors are capable to measure micro-displacements, with lower intrusiveness. Therefore, they can be used for monitoring the bond-slip of old RC structures as way of to collect information, essential to assist the owners to adopt cost effective, efficient and safer maintenance measures. Copyright (C) 2018 Elsevier B.V. All rights reserved.