Joints & Concrete Spalling Repair
Construction joint failure & concrete cancer repair
The Construction joints below are for the most part no longer sealed adequately. This property is in danger of major material loss from behind the all and wall rotation as the wall will lose stability without support from behind.
This property has walls that are 'outer joints' where the wall is not a straight line, it is around a corner and the panels if left without sealing will overtime begin to slump. Simple fix - reseal.
Throughout the system we have seen many attempts to correct, some have been successful, others not. It is important to do it right to the toe of the wall and to do it with the correct sealant products otherwise it will not last and it will not prevent loss at the toe.
Construction Joint Deterioration- Reseal
Revetment walls are built with construction joints to allow them to expand and shrink with temperature changes. Usually, these joints are sealed with a rubber material to prevent water and soil from being lost through them. However, over time, the rubber deteriorates - especially below the high tide line (crabs seem to love it!).
When the rubber deteriorates sand and soil can be lost through the joint causing subsidence behind the wall. Resealing joints with the correct marine grade products is a part of our scope of works to bring your revetment wall back to it's best.
After cleaning and drying the joint, our team prime and reseal with a marine sealant which will prevent the joint from allowing material to come from behind the wall.
We came across many walls with minor spalling and a few with concerning spalling issues. Hairline cracks in the wall will allow salt water to penetrate and eventually lead to spalling. Whole wall sealing is required to slow this process.
In the case of this wall - treatment of the spalling is urgently required. Exposed reo-rusting, hairline cracks horizontally stretching beyond the spalling, indicate the problem is going to spread .
These walls have small spalling spots appearing- again treating and whole wall sealing will slow the deterioration process.
Revetment wall concrete cancer repairs
Revetment wall concrete spalling or concrete cancer occurs when salt water causes corrosion of the steel reinforcing inside the wall. Sometimes this is due to poor construction, where steel is too close to the surface. Sometimes the salt water penetrates through small cracks in the wall. As the steel corrodes, it expands and causes surrounding areas to crack. In severe cases the concrete falls away, further exposing the steel and exacerbating the problem.
Above the water-line is called The Spalling Zone as it is most prone to paste layer deterioration. In this photo, the capper on the top of the revetment wall has reinforcing steel (reo) too close to the surface (due to a construction issue). Our team will correct the rusting reo and patch the concrete to protect from further rust and deterioration.
This photo shows a footing of a wall which has cracked, allowing material to flow through the wall causing subsidence issues. Rock will be reinstated against the footing. In some cases, a layer of geo-fabric across the footing is required to assist in this correction.