How to stop rust inside concrete?

Question

I have an old Garage, made from Concrete. The Concrete has metal rods inside it, some of these have rusted and are causing the Concrete to crack and fall off. Can I treat the rust and stop further problems?

Answer 1

What you are experiencing is galvanic corrosion of the reinforcing steel. The problem occurs when contaminants such as road salt get into the concrete and initiate corrosion of the steel. This problem is common in North America where salt is used to deice roads or in coastal areas subject to salt water spray.

There are systems which can be applied to the concrete but they are expensive and their use is usually limited to highway bridges and large parking structures. In addition these systems require that the concrete be fully repaired prior to the application. For a small structure, the only solution would be to chip out all the delaminated concrete, sand blast the steel and replace the concrete. At best this will give you about 5 years before the problem reappears.

Answer 2

What happend is the rebar ( the metal rods), were too close to the face of the concrete and as they rust they expand,and the concrete blows out, (similar to what tree roots do to sidewalks ), You have to dig out the concrete, get the rust off,( as best you can ), epoxy the exposed rebar and patch the concrete. Labor intensive, but it will add life to your garage. The rebar '' should be about 1 1/2 '' from the face of the concrete, Good luck !

Answer 3

You cant it is called "concrete cancer" Where the metal rods (called re-bars) have rusted and has caused the concrete to crack with the pressure.

A lot of 1960,s building seem to suffer from this condition.

The answer above mine has "hit the nail on the head"

Answer 4

Sorry you cannot, just pull it down.

Answer 5

It is not concrete cancer - that is a chemical reaction between the atmospheric CO2 and the salts in the cement binder.

It is because the concerete cover is too light in places allowing rust to form. Since steel expands as it rusts whis makes the concrete shell off.

Depending how far it has gone and if it is localised you could clean back and patch repair. I would paint the concrete with a rubberised paint in order to prevent water and air causing further damage. Monitor carefully and make sure no major structural bits are affected.