International Concrete Abstracts Portal

Professor Carolyn Hansson’s remarkable journey began in England, during the turbulence of the Second World War. Despite the hardships of wartime and the limitations imposed by rationing, Carolyn was raised in a nurturing environment by parents who instilled in her a deep respect for learning and perseverance. These values would guide her through an exceptional academic and professional life. As the sole woman at the Royal School of Mines, Carolyn studied metallurgy at Imperial College, where she later earned her PhD, focusing on superconductivity and crystal structures at liquid helium temperatures. Her postdoctoral path led her from industrial research at Martin Marietta Laboratories to academic positions at Columbia University and the State University of New York at Stony Brook, and later to Bell Laboratories in 1976. Her pivotal shift into corrosion science began in 1980 at the Danish Corrosion Centre, where she worked on a new type of cement and corrosion of steel in concrete. From Denmark to Canada, Professor Hansson continued her research at Queen’s University and later at the University of Waterloo, building an enduring legacy in the field of steel corrosion in concrete structures. Over the decades, Carolyn’s contributions to corrosion research have shaped and guided generations of engineers and scientists. Her pioneering studies—on electrical resistivity of concrete, quantifying reinforcement corrosion rates, and understanding the complex role of chlorides—remain foundational in the field. Her investigations into corrosion inhibitors, electrochemical chloride extraction, effects of concrete cracking on reinforcement corrosion, and corrosion-resistant steels continue to influence global practices in infrastructure resilience. This Special Publication celebrates more than 60 years of Professor Hansson’s contributions as a scientist, educator, and mentor. The papers collected here, presented at the 2025 Spring Convention in Toronto, reflect not only the lasting relevance of her work but also its future promise. Her vision stands as both a mirror to the past and a beacon for innovations yet to come in corrosion-resistant construction. O. Burkan Isgor David Tepke Ceki Halmen Neal Berke

Corrosion of reinforcement is a common deterioration problem for reinforced concrete structures at coastal areas causing early failure, increased maintenance costs, and significant safety problems. This paper combines a wellestablished diffusion-based service life estimation method with recently developed data-driven models on surface chloride concentration accumulation and critical chloride threshold distribution data to probabilistically analyze the effect of design parameters such as water-cement ratio (w/c), cover depth, and admixed chloride content in various coastal exposure zones. Results indicate that the used probabilistic analysis can result in changes to estimated service life values by an order of magnitude. Although w/c and cover depth were the most significant factors affecting the service life, parameters such as wind speed, temperature, exposure zone, and distance from the coast were identified as influencing the service life of coastal structures.

Concrete is an efficient material in terms of mechanical strength and functionality, but whose durability is one of present challenges that need particular attention to preserve the reinforcement absent of corrosion during the nominal service life. Present trends on modelling by performance make more complex the quality control testing and lengthens the characterization of new low carbon cement concretes. In present work is presented concrete resistivity as the single parameter able to characterize both corrosion periods through the corresponding mathematical expressions. Resistivity is a non-destructive test which could qualify concrete from its early ages. Based in the relation between diffusivity-corrosion current and resistivity, an integral model based in the resistivity measured at short term in the same specimens than mechanical strength (cured humid), is described. It is also analysed the analogies between the diffusivity and corrosion current and the influence of climate in the resistivity for future challenge of predicting the impact of climatic change.

A review of corrosion literature on corrosion of steel in concrete clearly shows that Carolyn Hansson’s work and vision mirrors the exponentially increasing interest on the subject since 1980s. During the time Dr. Hansson has been contributing to the scientific community, significant advancements have occurred in understanding and controlling corrosion of metals in concrete. This paper discusses some of the key advancements over the last six decades as Dr. Hansson was making her mark on the industry. The recognition of the role of corrosive environments, development and roles of committees in providing forums for experts, service-life modeling, electrochemical control, and other topics are discussed. Finally, a perspective on where the industry may be going in the future years is offered.

This paper demonstrates how a model that includes the chemical reactions in concrete, as well as the tortuosity of the concrete, can be used to predict the effects of cations on the ingress of chloride and changes in the hydroxide levels. Scenarios using low and high C3A cements exposed to NaCl, KCl, CaCl2, and MgCl2 are modeled. The predictions are compared to test data presented several years ago by Professor Hansson. The modeling provides a rapid means that can be used to assess both the salt and cement type on the corrosion susceptibility of embedded steel reinforcement in concrete.