Remote monitoring of concrete condition (REMOCC)

Steel Fibre Reinforced Concrete is gaining market share because of lifetime performance improvements and the opportunity to reduce or eliminate rebar. Previous work has shown that some classes of reinforcing steel fibres can act as passive sensors which can be inspected using external electromagnetic sensing. It was demonstrated that these passive sensors indicate reversible and irreversible effects in concretes loaded and unloaded up to eventual failure.

The sensing work undertaken in the project was initially based on an off-the-shelf instrument using Alternative Current Frequency Modulation (ACFM) or variant. Although successful in demonstrating the feasibility of the approach even at the low steel fibre concentrations used industrially in FRC (around 2%) it was limited both in terms of spatial resolution and penetration depth. Development of the sensor technology is now needed to optimize for the sensing application to improve so that condition of concrete structures can be monitored through life as part of asset management.

Downsteam innovations are also anticipated. Easy integration of sensing capability into concrete structures will improve competitiveness in civil engineering design, build and maintainance by

* confirmation of distribution of fibres at specified levels
* allowing leaner design to reduce total mass of concrete in large structure with consequential reduction in embodied energy/carbon
* indications of damage state after progressive or singular damage events so structures can be repaired instead of replaced
* the project will help accelerate the displacement of rebar by FRC. Rebar installation is expensive both in cost and time and also suffers from a high accident rate, so the shift towards FRM will enhance competitiveness