A Novel GFRP-FBG Smart Steel Strand and its Properties Research

Abstract

Prestress strands are the key parts of the prestressed structure, and the stress of the prestressed strands is one of the important indicators to assess prestress component security. Unfortunately, up to date, there are no qualified techniques to handle this issue due to that it is too hard for sensors to survive the harsh construction environments and the time-dependent service life of prestressed structures. In this paper, a novel smart steel strand based on the technique of GFRP-FBG rebar was introduced, and its sensing principle has also been given in details. The novel smart steel strand has been tested by serious experiments to research its mechanical and sensing properties. The monitoring results show that the mechanical properties of the smart strands are similar to ordinary strands, and its sensing properties include that distinguish-ability is less than 0.466% F•S, hysteresis less than 2.15% F•S, repeatability less than 1.32% F•S, linearity less than 0.86% F•S, and overall accuracy less than 2.67% F•S. Such kind of GFRP-FBG smart steel strand can be used for both structural and functional materials and applied in practical prestressed structure.