Technical Information

The PileJax™ Advantage

Speed – Due to the patented locking system, and high strength light weight construction, PileJax™ is the most diver friendly system on the market. No wrapping of piles is required. No painting of coatings underwater. No nuts and bolts to individually tighten and torque up. The PileJax™ system is made to order, not made in place by the dive team.

Strength – Independent testing by University of Southern Queensland confirms that a correctly executed PileJax™ repair will restore a 50% depleted concrete pile with exposed rebar to 95.8% of its original strength. The system can be used on any type of pile, concrete, steel or wood. In any profile.

Durability – Expected service life is over 45 years. Once the repair has been executed correctly it’s permanent. No need to rework or revisit the repair, no bolts to go missing over time, no wrap to come loose with wave action. Once the patented locking system is locked together and filled, the repair will last over 45 years.

PileJax™ The Real Advantage

The real advantage of the PileJax™ system is the reduction of billable hours. PileJax™ is so fast and easy to deploy it cuts down dramatically on billable hours across the project. Fast deployment, permanent results. PileJax™ Do it once and Do it right.

The PileJax™ the Pile Repair System

PileJax™ jackets are available in any lengths from 1m to 12m, in diameters from 0.5m to 2m. Wall thicknesses are between 3mm to 6mm, depending on application. However the PileJax™ system is modular, and therefore scalable. Custom sizes and configurations are available. Please contact PileJax™ for a custom solution beyond 12m.

PileJax™ is manufactured from high-spec fiber reinforced composite. Providing a lightweight, high strength, high durability jacket. As no metallic components are used in the construction the PileJax™ system, it is fully compatible with impressed current and sacrificial anode protection.

PileJax™ conducts in-house destructive testing (tested until failure) on random samples taken from every order prior to shipment.

Download our TDS and Installation Guidelines

Click on the image to view or download the full pdf file.

Click on the image to view or download the full pdf file.

Additional Technical Capacity

Modular Design

PileJax™ jackets are available in standard lengths from 1m to 12m, in diameters from 0.5m to 2m. Wall thicknesses are between 3mm to 6mm depending on application.

However the PileJax™ system is modular, and therefore scalable. The jackets can be made so that they telescope together. In the custom configuration the jackets become stackable, fitting end on end to produce the required length. Please contact PileJax™ for a custom solution beyond 12m.

Modular Design

PileJax™ jackets are available in standard lengths from 1m to 12m, in diameters from 0.5m to 2m. Wall thicknesses are between 3mm to 6mm depending on application.

However the PileJax™ system is modular, and therefore scalable. The jackets can be made so that they telescope together. In the custom configuration the jackets become stackable, fitting end on end to produce the required length. Please contact PileJax™ for a custom solution beyond 12m.

Midwater Only Repair

For a mid-pile / mid water only installation, a PileJax™ bottom seal is required. There are two types. A single use profiled foam seal that wraps around the pile, and a reusable seal that is comprised of a metal clamp, that bolts to the pile, and a foam sealing gasket. The single use seal is held in place with a strap. The jacket is then closed around this seal. The sealing face compresses as the jacket is closed, producing a water tight interface. This type of seal does not support the jacket on the pile. With the single use seal the jacket must be supported from above.

For large jobs, with multiple midwater only pile repair requirements, the reusable clamp and seal is recommended. The reusable seal is comprised of a metal clamp that bolts to the pile, and a flat foam seal. The jacket is made water tight by the interface with the seal and supported by the clamp. Straps are used to pull the jacket down onto the clamp forming the seal and stabilising the jacket. The clamp provides temporary support for the jacket during the filling operation. Once the repair has cured to a sufficient hardness, the clamps can be removed and used on the next repair location. For large jobs we recommend using several clamps in a leapfrog fashion.

Corrosion and Pile Degradation

Steel-corrosion-vs-concrete-pH-value-and-potential

Passivation

This graph is the Pourbaix Diagram. The diagram illustrates the zones of immunity, corrosion and passivation for steel, and the corresponding PH and electrical potential for each. Concrete protects steel by way of passivation. The high PH of concrete prevents a corrosion cell from forming. The PH of concrete can be reduced over time by water ingress. As this happens the steel reinforcing cage inside the concrete moves from the passivation zone to the corrosion zone. When this happens the concrete pile will start to break apart from the inside because steel expands as it corrodes.

Passivation

The above graph is the Pourbaix diagram. The diagram illustrates the zones of immunity, corrosion and passivation for steel, and the corresponding PH and electrical potential for each. Concrete protects steel by way of passivation. The high PH of concrete prevents a corrosion cell from forming. The PH of concrete can be reduced over time by water ingress. As this happens the steel reinforcing cage inside the concrete moves from the passivation zone to the corrosion zone. When this happens the concrete pile will start to break apart from the inside because steel expands as it corrodes.

Cathodic Protection

The immunity zone is generally achieved by cathodic protection system. By lowering the electrical potential of steel it becomes immune to corrosion. The cathodic potential (CP) of the steel can be lowered with sacrificial anodes or an impressed current system.

Divers can take CP readings with a Bathycorrometer to determine if a steel pile is protected, over protected, under protected or unprotected.

Material	Expected CP reading
Over protected steel	More negative than -1100mV
Zinc (used for pre and post calibration)	-1000mV to -1050mV
Protected steel	-800mV to -1100mV
Under protected steel	-640mV to -800mV
Unprotected steel	-450mV to 640mV
Monel	-50mV to -150mV

Over protection will not occur with sacrificial anodes, but may be achieved with an impressed current system.

No metallic components are used in the construction the PileJax™ pile repair system. The PileJax™ system is 100% composite, it is fully compatible with impressed current and sacrificial anode protection.

Pitting Corrosion

The corrosion of a steel pile can be localized, and not necessarily uniform across the entire surface. Pitting Corrosion is a localized corrosion cell that selectively attacks an area of the steel pile. Once a pitting corrosion cell forms it is self-propagating. The electrolyte (water) inside the pit becomes more acidic aiding the reaction. Pitting corrosion cells are of particular concern for steel piles as they are often harder to detect, the pit can be obscured by corrosion product (rust), and the cell can relatively quickly punch a hole through the pile. This not only reduces the loading bearing capacity of the pile but also allows freshly oxygenated water and/or air to interact with the internal surface of the pile.

Pitting Corrosion

The corrosion of a steel pile can be localized, and not necessarily uniform across the entire surface. Pitting Corrosion is a localized corrosion cell that selectively attacks an area of the steel pile. Once a pitting corrosion cell forms it is self-propagating. The electrolyte (water) inside the pit becomes more acidic aiding the reaction. Pitting corrosion cells are of particular concern for steel piles as they are often harder to detect, the pit can be obscured by corrosion product (rust), and the cell can relatively quickly punch a hole through the pile. This not only reduces the loading bearing capacity of the pile but also allows freshly oxygenated water and/or air to interact with the internal surface of the pile.

Pitting corrosion is a very localized form of galvanic corrosion. All that is required is a small area of depassivation. This small area then becomes anodic, and a potentially much larger area of surrounding steel becomes cathodic. Just like the protection provided by a sacrificial anode, this small anodic area will sacrifice itself to protect the potentially much larger cathodic area around it. This, and the decrease in the PH of the electrolyte, is why pitting corrosion can propagate relatively quickly.

No copyright is claimed on anything under the ‘Corrosion and Pile Degradation’ heading as it is for educational purposes.