This issue of Structures and Buildings opens with a timely briefing, launching a collection of seven papers that form a coherent path for sustainable structural engineering. The contributions span innovative materials, resilient design and evolving design philosophies that place safety, repairability and whole-life performance at the forefront. Collectively, they trace a clear trajectory from laboratory innovation to the realities of construction, maintenance and policy, a path the built environment profession must navigate with urgency, if it is to make a meaningful contribution to the United Nations 2030 sustainable development goals (SDGs).
The urgency of this endeavour cannot be overstated. The latest United Nations (2024) assessment warns that targets such as ‘Climate action’ (SDG 13) and ‘Sustainable cities and communities’ (SDG 11) remain critically off track. With the built environment responsible for nearly 40% of global carbon dioxide (‘carbon’) emissions, the engineering community has a central role in reversing this trend. The practical, scalable solutions highlighted in this issue exemplify how structural performance can be reconciled with resource stewardship, offering pathways to both resilience and sustainability.
The briefing by Trott et al. (2025) sets the tone by framing building-scale decisions within a rigorous life-cycle perspective. By integrating life-cycle assessment, whole-life carbon accounting and ecological footprint metrics, the authors offer a pragmatic methodology that can align design choices with national and international climate targets. Crucially, their work bridges the micro material and component decisions, and the macro policy and regulatory frameworks, offering an analytical toolkit for engineers, architects and decision makers seeking measurable carbon reductions.
Several papers tackle the raw materials challenge, a first step in reducing the construction industry’s environmental footprint. Cai et al. (2025) address the ecological damage caused by river sand extraction by demonstrating manufactured volcanic scoria sand as a viable substitute in steel-fibre-reinforced concrete. Their experiments, complemented by the innovative application of machine-learning models in predicting material performance under freeze–thaw cycles in a cold climate, show how alternative aggregate sources can both conserve ecosystems and improve durability in cold climates. Rostami et al. (2025) pursue a parallel line of inquiry for binders, optimising self-compacting geopolymer concretes made with industrial by-products such as ground granulated blast furnace slag and fly ash. Their work highlights the promise and practical challenges of geopolymer mixes, steel fibres deliver clear benefits in strength and fire resistance, while hybridisation and fibre–matrix bonding remain design issues requiring further optimisation.
Material innovation does not stop at concrete. Thakur and Senthil (2025) examine sustainable bricks made from modified fly ash and crumb rubber, assessing their seismic performance when used as wall infill. Their cyclic loading tests reveal that crumb rubber-modified bricks, particularly within confined masonry frames, deliver superior energy absorption and crack resistance compared with traditional clay bricks, an encouraging result for affordable, resilient construction in seismic regions.
While material efficiency and alternative resources are essential, resilience in the face of dynamic loads and rare events requires new devices and connection philosophies. Ye et al. (2025) introduce an inventive scissor-amplified nodal damper that converts small nodal deformations into amplified shear strains in a viscoelastic element. This mechanism overcomes a core limitation of conventional dampers – their need for large inter-storey drifts – and opens up the potential for unobtrusive damping solutions at beam–column joints. The device is a promising concept. The next steps the authors rightly identify include prototype testing, durability studies and design guidance; these are essential before widespread adoption.
Taheripour and Saffarian (2025) focus directly on repairability, a central principle of sustainability that is too often overlooked. Their damage-control beam–column connection intentionally concentrates inelastic deformation in a replaceable stub-end plate sub-assembly. Experimentally validated, this controlled weak link limits damage to replaceable elements, protecting primary beams and columns and simplifying post-event repair and life-cycle cost management. This approach reframes seismic design from one of sacrificial damage to one of predictable, serviceable performance, a shift with clear implications for codes, procurement and asset management.
Two contributions investigate the ductility and toughness properties of fibre-reinforced and hybrid concrete systems. Hamad and Dehestani (2025) demonstrate that ductile high-performance concrete beams with low conventional reinforcement can achieve satisfactory flexural performance when strengthened with glass-fibre-reinforced polymer and micro-steel fibres; careful mix control with lower water-to-binder ratios and the use of optimised superplasticiser is pivotal. Cao et al. (2025) extend the fibre conversation to composite box girders, showing that steel hybrid fibre-reinforced concrete can substantially increase ductility and ultimate flexural capacity when combined with adequate shear connectors and appropriate fibre geometries.
Taken together, these papers trace three converging themes. First, circularity – substituting natural aggregates, using industrial by-products and rethinking the mortar of modern construction all reduce embodied impacts and protect ecosystems. Second, resilience through design – damping devices, replaceable connections and confinement strategies reallocate inelasticity to manageable, serviceable components, reducing long-term repair burdens. Third, the analytics and tools to scale change, life-cycle assessment, machine learning and rigorous experimental programmes bond innovation to practice by providing quantifiable performance and risk metrics.
For the research community and practitioners, the path forward is clear but ambitious. Promising laboratory results must be taken into field trials, durability and supply chain analyses must accompany performance claims, and standards bodies must be engaged early so that innovations translate into specifications and code provisions. Policymakers and asset owners should embrace procurement models that reward longevity, repairability and whole-life carbon performance rather than lowest first cost. Finally, interdisciplinary collaboration between materials scientists, structural engineers, architects, data scientists and ecologists will be essential to scale these solutions responsibly.
The papers in this issue provide both evidence and direction. They remind us that sustainable structural engineering is not merely a set of reduced-impact materials, but a systems challenge that demands new devices, new design philosophies and new metrics for success. As the 2030 SDG targets approach, the profession must transition from evidence to action, by piloting, standardising and mainstreaming the innovations reported here, so that they alter ordinary practice at scale. In doing so, engineers can help deliver structures that are not only safe and durable but also materially prudent and repairable, the foundations of a truly sustainable built environment.
