Real‐time corrosion monitoring of an ultra‐high performance fibre‐reinforced concrete offshore raft by using an autonomous sensor system

Abstract

The excellent high-durability features of ultra-high performance fibrereinforced concrete (UHPFRC) have been verified in laboratory studies, but its performance under service conditions are being studied. Indeed, structural health monitoring (SHM) can be considered an efficient strategy to assess built structures in which concrete matrix performance differs from that those found when assessing laboratory samples (variable actions, cracking, etc.). This work presents INESSCOM, an automated corrosion rate monitoring system, as an innovative support to SHM strategy to monitor UHPFRC structures in terms of durability. Its innovation lies in its durable and multi-parametric sensor designed to be embedded in multiple parts of a structure. The results from previous laboratory tests and those obtained during real-time monitoring of an offshore UHPFRC raft are presented. Acceptable deviation of 20% was obtained in corrosion rate measurements with the advantageous referenceelectrode-free cell of the sensor with respect to the classical three-electrode cell. Furthermore, sensor provided accurate corrosion measurements in UHPFRC despite its extremely high electrical resistivity and large amount of steel fibres. After 17-month monitoring of the UHPFRC raft, excellent performance was evidenced under service conditions with corrosion rate values always <0.1 μA/cm 2 . Conversely, corrosion rate reached 0.4 μA/cm 2 in a conventional concrete specimen installed for comparison. Corrosion initiation and propagation stages were clearly defined through the corrosion-penetrationdamage (μm) diagram obtained for the specimen. Present work positions INESSCOM as an innovative support to structural health monitoring strategy in UHPFRC structures.

OC, HPC, UHPC and UHPFRC Corrosion Performance in the Marine Environment

“…It allows for rebar corrosion analysis by studying the response of steel to potentiostatic-type disturbance. The PSV method has been used in other studies [131,132], and is also employed for corrosion monitoring systems in RCS [133]. In this case, measurements were taken with an Autolab PGSTAT 100 Potentiostat.…”

Corrosion Assessment in Reinforced Concrete Structures by Means of Embedded Sensors and Multivariate Analysis—Part 1: Laboratory Validation

“…One of the examples that has attempted to respond to these challenges is the INESS-COM (Integrated Sensor Network for Smart Corrosion Monitoring) monitoring system. This tool appears in previous works [70][71][72]. It is a smart system composed of control points located in different areas of the analysed structure.…”

“…The advantages that distinguish the PSV method from other techniques are that it allows work to be done with 2-electrode cells and that its processing can be automated. Thanks to these advantages, this tool has already been implemented in real structures and works autonomously [70], although the authors are still working on upgrading and refining it [77,78].…”