Concrete is the most used building material in modern-day. According to Cement Concrete & Aggregates Australia (2020), 70% of the world’s population lives in a structure that contains concrete. As durable as it may seem, concrete can be prone to concrete cancer, a serious issue that could cost a fortune to rectify and be an immediate danger to people.

Concrete cancer is the result of a carbonic acid forming and corroding in the steel that is reinforcing the concrete. As the corrosion develops, the steel will naturally expand and cause the concrete to crack. Once it starts cracking the steel is exposed to the elements, causing further rust and an even bigger problem. The concrete deaminates, causing the concrete to break away, resulting in spalling. Spalling affects the overall strength of the concrete and poses an immediate danger to people walking under the deteriorating structure.

The cause of concrete cancer can be traced back to the pouring of the wet cement; if the reinforcing steel is poorly treated, or placed to close to the surface of each concrete slab, the steel is prone to water exposure which could trigger the corroding process. Other causes include the use of incompatible metals causing reactions in the reinforcement, and/or pre-existing fractures to the concrete. Concrete cancer is a common problem along the Australian coastline, due to the constant exposure of ocean spray.

If you notice cracking concrete in your building structure, or distinctive rust stains coming out of the concrete, it is time to contact a professional. If left unattended, internal leaks and drips may occur. The most preventative tips for concrete cancer are to do regular check-ups and deal with cracks as soon as they appear. If the cancer is predominant, the spoiled concrete and steel need to be removed and replaced with new reinforced concrete.