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

It is well known that the steel–concrete interface (SCI) influences corrosion of steel in concrete. Numerous factors related to the SCI have been hypothesized to affect the mechanism of corrosion initiation and propagation, including steel surface characteristics, interfacial concrete properties (voids, cracks, etc.), and conditions related to the exposure (e.g., SCI moisture state). This contribution offers an overview of current knowledge on these aspects. Additionally, recent advances toward a fundamental understanding of corrosion-related processes occurring at the SCI are highlighted, including a novel experimental methodology for studying the steel surface behavior, imaging of the SCI moisture state, and the impact of macroscopic voids. Finally, perspectives for future research are given.

The electrical properties of concrete are being increasingly used to assess concrete resistance to fluid transport. Electrical measurements are strongly dependent on sample conditioning, which includes the degree of saturation. This paper presents an analytical approach for interpreting electrical measurements in partially saturated concrete. Previous approaches have used a power law to describe the influence of saturation. This paper proposes a saturation function that accounts for the contributions of the entrained air voids, the capillary pores, and the gel pores (the GCA function). The proposed approach is demonstrated for high performance, internally cured concrete mixtures tested between the ages of 30 d and 120 d. The power function had a greater measured uncertainty than the GCA function, which performed better at both high and low degrees of saturation. The resistivity of specimens submersed in simulated pore solution was measured as was the resistivity of sealed specimens. The sealed specimens have a degree of saturation that is similar to those at the nick point (matrix saturation), with an offset consistently only due to the self-desiccation of the binder.

Reinforced concrete is prevalent in construction for its strength and longevity. However, it can be susceptible to corrosion when exposed to chloride ions, particularly in areas affected by de-icing salts and marine environments. The technique known as Electrochemical Chloride Extraction (ECE) helps combat this corrosion by pulling chlorides away from the reinforcing steel and raising the concrete's pH around the steel. This paper examines the technique's development, the electrochemical reactions, and its effects on corrosion rates. Although ECE can dramatically lower chloride-induced corrosion, immediate post-treatment measurements often reveal increased corrosion rates as the passive oxide layer is re-established. A comparison of Linear Polarization Resistance (LPR) measurements before and after ECE illustrates the technique's effectiveness.

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.