Australia is positioning itself at the international forefront of long lasting, more sustainable construction materials development if proposed changes to the concrete durability criteria are greenlighted.
Existing concrete building materials international standards fall short of addressing chloride-induced premature corrosion believes Farhad Nabavi, a concrete sustainability expert working with Xypex Australia. The problem at the heart of the current international standards is that they don’t offer any solutions, or even address the issue.
“The chloride diffusion coefficient is one of the most important durability criteria for concrete, but we don’t yet have these factors in our standards, not just Australian standards but even US standards, concerning the chloride-diffusion coefficient for concrete as a durability criteria. They generally only make reference to the mention water-cement ratio, the minimum amount cement, or cracking,” explained Mr Navabi.
Recent research has found chloride-induced premature corrosion to be the dominant process of premature concrete deterioration, causing 90% of Australia’s total concrete corrosion!
The Concrete Institute of Australia is shifting towards establishing parameters and criteria to deal with chloride-induced premature corrosion which take into account areas which impact concrete durability and structure service life.
Industry will need to be offered training to help implement the building practice improvements if the new criteria are to work, as new standards require a change in thinking.
If the implementation of the criteria is successful then the durability, longevity and quality of our country’s built environments will be enhanced into the future.
As most of our country’s population is concentrated along the coastline in major cities, chloride-induced premature corrosion poses a major threat.
“The liveable cities in Australia are all along the coastline with many built assets oftentimes within just one or two kilometres of saltwater environments. Here in Melbourne we have to conduct frequent and extensive repairs because of that chloride diffusion into concrete structures”, pointed out Mr Navabi.