Prevention of the “concrete cancer” that eats away at buildings along Australia’s coastline and costs an estimated $200 million annually to repair could be as simple as applying the correct coating.

UQ civil engineering PhD student Farshid Homayouni has devised a test to grade concrete coatings by measuring their resistance to carbon dioxide.

Concrete is often coated to shield it from the cancer, which occurs when carbon dioxide or wind-borne salts penetrate its pores.  The salt eats at the protective layer and corrodes the steel reinforcement inside.

Mr Homayouni used more than 300 concrete samples during his research, most of which he cast but some he drilled out of buildings and the historic Story Bridge.

The samples were then exposed to a year of weathering before being tested in a gas diffusion rig to show coating degradation.

Mr Homayouni said his test was more reliable than those of manufacturers because he used concrete from the field, not fresh coatings on ceramic tiles or paper in a laboratory.

There is no industry standard for types of concrete coatings, such as water based, polymers and acrylics.

“Standard testing methods do not provide any dependable guidelines about the life of coatings in different environments, which means maintenance routines cannot be optimised,” Mr Homayouni said.

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