+chase® - ICCP System for Reinforced Concrete Structures - Corrosion Management System: Restoration

Corrosion of reinforcement steel in concrete is disruptive, costly and a result in a significant loss of embodied carbon. The longer the issue is deferred the higher the maintenance cost to repair, protect and often strengthen the structure. Impressed current cathodic protection (ICCP) has been used effectively over many decades to control corrosion. Commonly used ICCP anodes are manufactured from titanium with specialist precious metal oxide coatings in ribbon or discrete anode forms that can be difficult to install without design issues in respect to bond breaking between encapsulation mortar and parent substrate concrete but are also high carbon in their manufacturing.

The C-Probe +chase anode mortar addressed these issues by virtue of manufacturing as an alkali-activated cementitious material from industrial waste streams and no heat resulting in a very low carbon profile. When activated the powder binder forms as a hardened aluminosilicate geopolymer that is both conductive as an anode and acid resistant to provide ICCP longevity.

It is mixed with 3mm aggregate with working time controlled with conventional retarders to be retrofitted into concrete chases cut into reinforced concrete using a conventional methods and finishing tools. Its compressive and flexural strengths can be designed to match the parent Portland concrete with bond strength measured to 3.5MPa.

Operates within any reinforced concrete structural elements such as decks, beams, abutment walls etc. If multi-layer steel protection is required then there may also be a need to also drill discrete holes within the element to depth in order to throw current around the whole complex steel arrangements.

Laboratory tested at Sheffield Hallam University the anode has operated at 10x the normal current design densities before any acidification is seem proving anode longevity and dimensional stability.

Through the restoration of existing reinforced concrete structures such as bridge elements, parking decks, +chase® helps retain the embodied carbon by protecting steel from corrosion and preventing damage to the concrete cover that was created during its construction.

It eliminates the need for non-delaminated contaminated concrete to be removed or for reconstruction of partial or full depth structural elements. This eliminates the need for new steel and concrete, thereby preserving existing embodied carbon with limited new embodied carbon.

Features and benefits:

• For permanent and continuous operation.
• Single whole life application.
• Repurposing industrial waste streams
• Low carbon emission low energy manufacturing process
• Non-shrinkage
• Structural compatibility for compressive and flexural strengths
• Bond to existing concrete to 3.5MPa
• Acid resistant
• Provides greater flexibility with the design parameters that influence and enhance service life.
• Minimises bond break risk compared to MMO titanium ribbon anodes.
• 3D corrosion protection and control of complex steel arrangements.
• To be installed with the AchillesICP digital management system for remote operation and control.
• Corrosion rate embedded sensing allows data processing to provide service life tracking of performance.
• Full online performance record for due diligence purposes and permanent record of building/ structure performance.

Components:

• +chase® geopolymer ICCP anode mortar system
• CP101 and CP200 corrosion rate probes (four per zone).
• AchillesICP power, control and monitoring network.
• Electrical connections, wiring and environmentally-protected enclosures.
• AC (single phase,50/60Hz) and broadband connections at the Network Access Unit (NAU).
• AiMS online facility for ongoing performance management and reporting.