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

This month’s Q&A discusses the reinforcement stiffness ratio ρne that can be used for comparing the performance of various reinforcement types in slabs-on-ground and the design approach for glass fiber-reinforced polymer reinforcement in ACI/NEx MNL-6(23) based on percent reduction in unrestrained shrinkage strain from the enhanced aggregate interlock design of ACI PRC-360-10.

Internally cured concrete was used to repair bridge decks of the Wilson Dam in Muscle Shoals, AL, USA, and to provide a 100-year service life. The article discusses characteristics of internally cured concrete and the benefits of using it, as well as lightweight aggregates needed to produce such concrete and their properties.

Various reinforcement types can be evaluated to determine their relative performance in controlling the restrained shrinkage cracking behavior of concrete. Two sets of published test data on restrained shrinkage cracking of slabs-on-ground are analyzed, and a parameter suitable for comparing the performance of various reinforcement types is identified.

Current nonlinear modeling software for concrete frames typically employs line elements with plastic hinges defined at user-selected locations. While this is a simple and computationally efficient approach, a number of drawbacks limit its application. They include the challenges with defining the interacting shear and moment hinge curves, uncertainties with hinge locations and lengths, and difficulties in capturing the post-peak response. Two-dimensional continuum methods address these limitations, but their computational cost limits their applicability. This study presents an alternative modeling method, and associated computer software, with the objective of combining the simplicity of frame elements with the accuracy and result visualization capabilities of continuum methods. The method, developed in the last two decades, employs a distributed-plasticity, layered-section approach based on the Disturbed Stress Field Model (DSFM). The distributed-plasticity approach eliminates the need for defining plastic hinges while the DSFM enables capturing the shear, moment, and axial force interaction. The total-load and secant-stiffness formulation provides numerically stable solutions, even in the post-peak region. This paper presents an overview of the theoretical approach, unique aspects, and capabilities of this method. The validation studies undertaken for 148 experimental specimens, subjected to static (monotonic and cyclic) and dynamic (impact, blast, and seismic) load conditions, are also presented.