Experimental Studies of Laboratory Samples of Fiber-Optic Sensors within Reinforced Concrete Building Construction. Part 1: Overview

Technical monitoring of building structures is necessary to improve the efficiency and safety ones. Early diagnosis in real time and timely notification of the danger of destruction of a monolithic reinforced concrete building structure, as well as the finding of the exact location of cracks formation is a very urgent problem. Development of control tools for the timely identification of hidden defects in extended building structures, monolithic reinforced concrete foundations etc. requires experimental studies of fiber-optic sensors in the observation systems. In the first part of the study, an overview of experimental investigations related to building structures monitoring using fiber-optic sensors (FOS) was carried out. The second part contains a summary of our experimental studies on the control of the technical condition of building structures. The optimal parameters for the configuring system are proposed. It is shown that under mechanical stress on FOS, the spectrum of the light spot changes. This makes it possible to determine the exact numerical values of the deformation. The use of the G652 standard optical fiber as a distributed source for continuous monitoring of the technical condition of buildings and structures allows monitoring changes in the parameters of mechanical loads, stresses, and deformations. A distributed FOS can be both a sensing element and a communication channel. The use of fiber in the control system will allow achieving high energy efficiency, since the attenuation of the optical signal in the fiber is very small. The results convincingly show that with the means of quasidistributed sensors, it is possible to reliably identify the damaged area, and using the optical reflectometry method to determine the place of destruction with an accuracy of one meter.