Cement-Free Concrete Combats Corrosion and Fatbergs

Jan, 2021 - By SMI

The newly developed cement-free concrete reduces corrosion by around 96% and eliminates the formation of fatbergs.

Concrete corrosion and fatberg plague sewage systems, leading to costly and disruptive maintenance. The cement used to build concrete sewerage systems worldwide does a powerful job of helping to wash out waste, however, does have some drawbacks. Now, the research team from the RMIT University (Australia) has developed a cement-free concrete that helps in combating corrosive environment found in sewage pipes, as well as avoiding the build-up of fatbergs. The research was published in the Resources, Conservation & Recycling journal. Corrosion occurs when the steel rebar within reinforced concrete structures rusts.

A fatberg is a jellied mass in a sewer system formed by the combination of non-biodegradable solids (flushed). These build-ups of grease, oil, and fat in sewerage systems, as well as general corrosion over the years, costs billions in repairs and replacement pipes. Although ordinary Portland cement is widely used in the construction industry, some of its applications have long-term durability issues. Portland cement is the most common type of cement in general use around the world. Chemical compounds used while producing Portland cement make it vulnerable to corrosion in the highly acidic environment of the sewerage system.

According to the researchers, the concrete sewage pipes around the world have faced durability issues, and so far, there was no such material that could protect the sewer system from fatbergs and corrosion. The researchers used by-products (such as hydrated lime, slag, and nano-silica with fly ash) of the manufacturing industry to develop a new cement-free concrete. The team tested the newly developed cement-free concrete and found that the concrete exceeded the required strength standards for sewage pipes. Moreover, the unique blend improves longevity. The team states that the new cement-free concrete is eco-friendly, reduces corrosion by around 96% and eliminates the formation of fatbergs.