Simona Bovi

This study introduces a dynamic Life Cycle Assessment (LCA) approach tailored to the concrete industry, proposing an index to measure CO ₂ -equivalent emission reductions per square meter (m ² ) across the service life of conventional concrete structures. Following a review of current LCA methods, the research identifies gaps in existing approaches, particularly the frequent omission of CO ₂ absorption due to carbonation and environmental variability throughout the lifecycle of concrete elements. To address these issues, an index has been developed to ease the quantification of CO ₂ absorption by structural components. The method is applied to multiple cement types classified under the EN 197-1 standard, which allows the performance of comparative environmental impact assessments across different materials. Results are presented according to variations in cement substitution percentages, compressive strength, the cement-to-concrete ratio in kilograms per cubic meter, and exposure class. In order to validate the proposed index, a case study is conducted on thin-walled elements made with Cementitious Textile Composite (CTC), evaluating the carbonation potential of different cementitious mixtures with diverse percentages of supplementary cementitious materials (SCMs). The analysis considers elements with thicknesses of 3 mm and 7 mm under different exposure classes, assessing their carbonation rates and the respective CO ₂ sequestration over a 20-year period. The results highlight how elements with higher surface-to-volume ratio present a greater CO ₂ uptake, leading to a more pronounced cooling effect and a reduction in Global Warming Potential (GWP). The validation phase highlights the impact of initial emissions and the absorption on the overall GWP balance, demonstrating this dynamic LCA method’s potential for reducing emissions more effectively than conventional static approaches. Finally, this LCA proposition may enable the incorporation of carbonation accounting in more reliable and accurate ways across existent building and construction LCA tools. Furthermore, such approach could also assist designers and other stakeholders to familiarize with carbonation processes and complex LCA modelling.

Building design has to deal with complex geometries and surfaces arising from current trends and “New European Bauhaus” initiative that imagines a sustainable and inclusive future that is beautiful for eyes, minds, and souls. This also relates to the rise of new design paradigms, such as 'user-centred design', which includes customized optimization approaches. The increasing adoption of customized components and unique solutions raises valid concerns about the optimal use of energy and resources. The study carried out stems precisely from these needs and focuses on the life cycle assessment of the technologies currently available on the market to realize the mentioned architectures. In the first phase of the study, a comparative assessment of the carbon footprint of the production process of selected technologies for custom geometries production was carried out: CTC (cement-textile composite), CNC milling (computer numerical control), 3D printing and adaptable membrane casting. These technologies have different process principles and consequently, to make it possible their comparison, independently of specific configurations, a parametric methodology was implemented based on the use of a bounding box that encloses the target shape. This made possible the creation of nomograms to identify the different volume ranges in which it is more convenient, in terms of global warming potential (GWP), to use one technology over another. The investigation is in line with SDG 13 (climate action) which calls for reducing environmental impacts through sustainable alternatives. Radar charts were then created to complete the analysis to compare the different technologies with respect to the main aspects of both sustainability and production.

At present, building design is faced with a need to properly manage complex geometries and surfaces. This fact is not only driven by the increased demand for visually stunning spaces but also stems from the rise of new design paradigms, such as “user-centred design”, that include bespoke optimization approaches. Nevertheless, the escalating adoption of customized components and one-off solutions raises valid concerns regarding the optimal use of energy and resources in this production paradigm. This study focuses on the Life Cycle Assessment of a novel Cement–Textile Composite (CTC) patented material. It combines a synthetic reinforcing textile with a customized concrete matrix, to generate rigid elements that are able to statically preserve complex spatial arrangements, particularly double-curvature surfaces. Moreover, the CTC offers a low-volume cost-effective alternative for custom-made cladding applications. The study performed a comparative carbon footprint assessment of the CTC production process in contrast to other technologies, such as CNC milling and 3D printing. To facilitate meaningful comparisons among diverse construction alternatives and to derive generalized data capable of characterizing their overall capacity, independent of specific production configurations, the present study implemented a generalized parametric shape of reference defined as a bounding box (BBOX), which encloses the volume of the target shape. Comparing different production technologies of the same shape with the same BBOX results in a significant carbon saving, up to 9/10th of the carbon footprint, when the CTC technology is adopted. The study therefore highlights the potential environmental advantages of CTC in the fields of architectural design and building engineering.