Valentina Tomei

Timber, with its prerogatives of low life-cycle impact, carbon storage, excellent strength-to-weight ratio, and good thermal and acoustic properties, represents an attractive for building systems in many regions. Moreover, disasters triggered by natural events have highlighted the benefits offered by structural timber in providing efficiencies for resilient and sustainable cities. The present paper presents an overview on the use of structural timber in constructions in Europe, with emphasis on new trends and research advancements in seismic-resilient cities. Importance is given to the potentialities offered by structural timber in promoting innovative and high-performing structural solutions for mitigating the effects related to natural events. Based on a bibliometric selection analysis, the paper focuses on: (i) new timber-based products and/or subassemblies used for low-, medium- and high-rise seismic-resilient constructions; (ii) timber-based solutions for combined seismic and energetic retrofits of existing masonry and reinforced concrete buildings or for realizing new buildings; and (iii) updating codes and guidelines. The peculiarities of each selected topic are discussed in detail and properly referenced. The aspects highlighted in the present research can represent guidance for experts in the sector, and for those now approaching, by identifying the current state of research advancement. On the other hand, they can also support practitioners in selecting new solutions and understanding the limits and potentialities offered by them.

The construction sector is a significant contributor to resource consumption and environmental degradation due to energy-intensive processes. To reduce consumption, reuse-based design strategies could lead to structurally efficient and environmentally friendly solutions. However, effectively incorporating reused elements requires advanced design methods that allow for their rational disposition. This paper presents an innovative design approach based on a metaheuristic strategy developed through genetic algorithms for the design of minimum-weight gridshells using reusable components. The methodology is applied to a dome gridshell, tested under different stock and boundary conditions. An expedited greenhouse gas assessment is then carried out to evaluate the environmental benefits of the reuse-based solutions compared to solutions composed entirely of new elements. The results are presented in terms of geometry, disposition of reused and new members, weight, structural performance (buckling factor, demand to capacity ratio, displacements), and greenhouse gas emissions. The algorithm is able to find the minimum weight solution for all the considered stocks, and to account for the different governing design criteria characterizing fully and partially constrained gridshells. Furthermore, it can also be used to determine the characteristics that the stock of reused elements should possess in order to achieve more sustainable design solutions.

Historic floors, including mosaics, stone slabs, and decorated pavements, are fragile elements that can be easily damaged during restoration works. Risks arise from falling tools, concentrated loads of scaffolding or equipment, and the repeated passage of workers. Traditional protection methods, such as plywood sheets, mats, multilayer systems, or modular plastic panels, have been applied in different sites but often present limitations in adaptability to irregular surfaces, in moisture control, and in long-term reversibility. This paper introduces an innovative approach developed within the 3D-EcoCore project. The proposed solution consists of a bio-inspired modular sandwich system manufactured by 3D printing with biodegradable polymers. Each module contains a Voronoi-inspired cellular core, shaped to match the geometry of the floor obtained from digital surveys, and an upper flat skin that provides a safe and resistant surface. The design ensures mechanical protection, adaptability to uneven pavements, and the possibility to integrate ventilation gaps, cable pathways, and monitoring systems. Beyond heritage interventions, the system also supports routine architectural maintenance by enabling safe, reversible protection during inspections and minor repairs. The solution is strictly temporary and non-substitutive, fully aligned with conservation principles of reversibility, recognizability, and minimal intervention. The Ninfeo Ponari in Cassino is presented as a guiding example, showing how multilevel knowledge and thematic mapping become essential inputs for the tailored design of the modules. The paper highlights both the technical innovation of the system and the methodological contribution of a knowledge-based design process, opening future perspectives for durability assessment, pilot installations, and the integration of artificial intelligence to optimise core configurations.

The building industry is a major consumer of resources and a significant contributor to environmental degradation, largely due to its reliance on energy-intensive materials and construction practices. In this context, the reuse of components from decommissioned structures offers a promising strategy for reducing the environmental impact of new constructions. Steel products are particularly suitable for reuse, as they retain their mechanical properties over time. However, the adoption of reused members requires a shift from conventional design approaches, which typically allow for free dimensioning of elements, toward strategies where components must be selected from available stocks and strategically integrated into new structures. This process demands a careful balance between geometric configuration, structural performance, and material availability. This paper presents a new design methodology for gridshells that integrates geometry and sizing optimization to maximize the use of reused members. The proposed approach was validated through application to a dome structure. The structural behavior was assessed through nonlinear buckling analyses, alongside a simplified evaluation of greenhouse gas emissions to quantify the environmental impact. The findings highlight the potential of reuse-based strategies to promote more sustainable structural designs.

The paper investigates the use of 3D-printed components made from Polylactic Acid (PLA) for the restoration of architectural and ornamental elements, focusing on architectural/structural components. The material PLA was chosen for its potentiality in respecting the principles of restoration, recognizability, reversibility and minimum intervention, thanks its visual appearance, very different from typical construction materials, biodegradability and affordability. The paper represents an exploratory study aimed to derive the characteristics of 3D-printed PLA components thought tensile tests on dog-bone samples, and to analyze the behavior of structural components, thought tensile and bending tests on small truss beam samples. Unlike previous works mainly oriented towards aesthetic reproduction, this study focuses on the mechanical performance of PLA components designed for structural integration in restoration projects. The results show that the 3D-printed PLA components exhibit an average tensile strength of 44 MPa and an average Young’s modulus of 1270 MPa, values consistent with literature for fully dense PLA prints, and peak loads of about 6.4 kN in tension and 5 kN in bending for truss elements. Furthermore, this study provides data useful for future numerical modelling of 3D-printed structural elements in PLA, aimed at predicting their structural performance and supporting the design phase.