Researchers Seek New Approach for Corrosion in Concrete Structures

In Applied Physics Reviews, researchers from Switzerland, the United States, Canada, and Norway advocate for a paradigm change in the science of forecasting corrosion damage within reinforced concrete structures. They discuss the severe flaws in using the chloride threshold concept for forecasting corrosion and say change is needed to address the growing challenges of aging structures losing functionality and potentially collapsing, greenhouse gas emissions, and the economy at large. To achieve this, a multi scale, multidisciplinary approach combining scientific and practical contributions from materials science, corrosion science, cement & concrete research, and structural engineering is needed.

The most common cause of degradation and failures of reinforced concrete structures is chloride-induced corrosion of its embedded steel. This is a pervasive, urgent problem that requires immediate attention and public awareness. An underlying concept of a chloride threshold is widely used, and all existing models to forecast corrosion performance of reinforced concrete structures exposed to chloride environments are based on this one common theoretical concept. But concrete is porous, and when exposed to salts, such as seawater or road salts, chloride ions can eventually penetrate the concrete and reach the steel. At some point, the protective passive layer will be destroyed, and corrosion may start. Depending on actual exposure conditions, corrosion may occur at a faster or slower pace.

In reality, steel corrosion within concrete is a continuous process rarely separable into uncoupled, sequential phases. The researchers say the focus should be placed on the quantification of the time- and space-variant corrosion rate from the moment steel is placed within concrete until it reaches the end of its service life. To achieve this, a multi scale, multidisciplinary approach combining scientific and practical contributions from materials science, corrosion science, cement/concrete research, and structural engineering is needed. Angst and his colleagues propose scientific research evolve away from the chloride threshold concept.

American Institute of Physics

New approach needed for forecasting corrosion within bridges, concrete structures: Paradigm shift urgently needed for forecasting corrosion within civil engineering structures.

Science Daily, 29 March 2022.

www.sciencedaily.com/releases/2022/03/220329114653.htm

Researchers Seek New Approach for Corrosion in Concrete Structures

Strategic Research Institute

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