Shape memory alloys (SMAs) have two distinct mechanical properties, superelasticity and shape memory effect. The latter property is often used in seismic and vibration-control devices, where their superelastic behaviour enables self-centering connections, dampers, and reduced residual deformation after earthquakes. The former property can be utilized to generate prestressing in structures. There are different sorts of SMA: some are only superelastic and some have only shape memory affect, and others have both properties.

SMAs have been widely explored for different structural applications such as seismic and vibration-control devices or prestressed strengthening in concrete, steel, masonry, glass, and composite structures, among others. This special session focuses on all sorts of SMAs that are used in construction, in particular, nickel–titanium (Nitinol), copper-based, iron-based SMAs among others. We aim to bring together recent advances in SMA-based technologies, with a focus on materials behavior, interface mechanics, com-posite action, structural applications, and design methodologies.

Iron-based shape memory alloys (Fe-SMAs), commercially known as Memory®-Steel, are a class of intelligent metallic materials that offer new opportunities for both repair and strengthening of existing concrete structures and developing innovative solutions for new construction. Activated by heating after installation, Fe-SMA elements generate prestress without hydraulic jacks or complex prestressing equipment, enabling robust and easy-to-install systems. This special session will bring together research and practice on applications in concrete construction, including pre-stressed flexural and shear strengthening of existing buildings and bridges, near-surface-mounted bars, strips, prestressed confinement, crack control, bond behavior, durability, monitoring and design approaches. Novel concepts for new structures are also encouraged, including prestressed precast concrete elements and prestressable connectors. The session aims to discuss how Fe-SMA systems can extend service life, reduce intervention effort in existing structures, enable novel prestressed solutions for new and precast construction, and support resilient, resource-efficient ageing concrete infrastructure and buildings.

Planned as Inspirative Lecture Session with an inspirative talk by Julien Michels, Marlon Hilscher, and Elyas Ghafoori: „Iron-based shape memory alloys for construction: from research to application“.

The transition to low-carbon construction depends on the ability to measure, compare and act on data relating to the impact of buildings on a large scale. However, methods, datasets and reporting formats remain fragmented across different regions and availa-ble tools. This limits the comparability required for benchmarking and standardization. This session brings together approaches that link three levels: the large-scale assess-ment of embodied carbon emissions and full life-cycle emissions; the digital platforms and interoperable data formats that make such assessments reproducible; and the benchmarking methods that transform measurements into design and policy deci-sions. Contributions range from methodological frameworks to open data infrastruc-tures, through to applied case studies in various geographical areas, including emerg-ing markets where primary data is scarce. The session aims to identify common ground regarding data formats, accuracy levels and benchmarking logic, promoting a shared direction for a comprehensive and comparable impact assessment. Expected contributions are from researchers, tool developers and practitioners working at the intersection of data and decarbonization:

Civil infrastructure is increasingly affected by ageing, deterioration, environmental actions, and growing demands for safety, resilience, and sustainability. Recently, machine learning has created opportunities for infrastructure monitoring and assessment, but most machine learning models are purely data-driven and may be difficult to trust in engineering practice when their predictions are weakly connected to physical mechanisms. Physics-informed machine learning offers a promising solution by embedding structural mechanics, material behavior, domain knowledge, and monitoring data into learning models, thereby improving interpretability, generalization, and decision relevance. This special session focuses on physics-informed methods for reliable assessment of buildings, bridges, tunnels, and other civil infrastructure systems. Contributions are invited on physics-informed machine learning, damage detection, durability prediction, digital twins, and predictive maintenance. Particular attention will be given to approaches that remain robust under sparse, noisy, or incomplete monitoring data and that demonstrate practical engineering applicability.

Over the last decades FRP reinforcement for new concrete structures and FRP strengthening systems for rehabilitation of existing structures, both for non-prestressed and prestressed applications, has become increasingly popular in practice. Design guidance on FRP reinforcement has become more prominent, thanks to Model Code 2020 and Eurocode 2 (annexes J and R). Within the scope of fib TG5.1, this session is dedicated to advancing the use of FRP in structural engineering and welcomes both research and industry perspectives on FRP applications in concrete structures.
The session will bring together leading academics, researchers, and practitioners whose work spans a wide range of FRP-related themes, including: sustainability and durability of using FRPs in concrete, structural behavior of reinforced or prestressed concrete implementing FRPs, strengthening and retrofitting techniques using externally bonded and near-surface mounted FRPs or textile reinforced mortar, development of guidelines and code provisions, and FRP systems and applications.

Bridges are an essential part of the critical infrastructure of countries and continents. Worldwide, the bridge stock is aging. However, simply replacing aging bridges is neither a feasible nor a sensible approach. There are many reasons against this, such as time and cost considerations, the availability of manpower to implement such measures, and the urgent global need to limit the consumption of resources, energy, and land. Therefore, preservation and retrofitting are increasingly taking precedence over demolition and new construction.
In this special session, experts from various countries will have the opportunity to speak and present the standard procedures for managing the bridge stock in their respective countries. True to the motto “Lessons Learned,” we aim to create a space for mutually enriching discussions and exchanges through concise presentations of country-specific approaches, the handling of specific problems, and the identification of advantages and shortcomings of existing regulations. The presentation of best-practice examples is also highly welcome.

Textile reinforcements made from carbon, glass, basalt or polymer fibres enable thin, durable and resource-efficient concrete elements. Their performance and durability depend on the physical and chemical characteristics of the fibre–matrix interface and resulting bond behaviour. This session presents recent research on surface treatments, coatings and impregnation strategies to improve, tailor and control bond in cementi-tious matrices, while addressing sustainability and recyclability.

Topics include:

• bio-inspired surface structuring and engineered interphases
• impregnation materials based on bio-based polymers, synthetic polymers and mineral systems
• coating and surface treatment technologies
• mechanical performance of textile-reinforced concrete as influenced by bond behavior
• experimental methods for characterizing fiber–matrix bond
• influence of environmental and exposure conditions, such as temperature, moisture, pH value and time, on bond performance
• debonding-on-demand concepts and recycling strategies
• Analytical and numerical simulation approaches of bond behavior of fiber and yarns in inorganic (e.g. cementitious) systems

This session will present investigations about the thermal behavior of FRP and the damage mechanisms of FRPs inside concrete elements or used for strengthening exist-ing steel-reinforced concrete elements. Elevated, as well as low temperatures in freeze-thaw cycles, will be relevant in this session.

As fiber-reinforced polymers consist of fibers and impregnation, properties such as the glass transition temperature play a crucial role in the load-bearing behaviour of structural concrete elements reinforced with FRP during a fire exposure. In addition,  the durability of external Carbon Fiber Reinforced Polymer (CFRP) strengthening systems of reinforced concrete (RC) structures subjected to freeze-thaw cycles (FT) is largely influenced by the durability and performance of the components involved. The session invites experimental and numerical investigations.