Monitoring of prestressing forces in prestressed concrete structures—An overview

This paper presents an overview of currently available methods for monitoring prestressing forces in prestressed concrete structure. Structural health monitoring has become an increasingly important tool for assessment of structural performance. Additionally, the value of the prestressing force represents an important parameter in prestressed concrete structures. Thus, several methods for monitoring prestress forces have emerged. This paper aims to consolidate the work performed in the area of prestressing force monitoring by presenting the most important advances and the directions for future research. The methods presented in this paper are based on indirect monitoring of the prestressing force through monitoring of another relevant parameter. They are divided into five general classes based on the relevant parameter they monitor: (a) vibration-based methods (based on acceleration), (b) impedance-based methods (based on electrical impedance), (c) acoustoelastic methods (based on wave velocity), (d) elasto-magnetic methods (based on magnetic permeability), and (e) strain-based methods (based on strain). The paper presents a table summarizing the comparison between the methods based on defined criteria.