PSI - Issue 84

Valentina Picciano et al. / Procedia Structural Integrity 84 (2026) 922–930

925

d)

Fig. 1. Strengthening configurations: a) steel jacketing; b) RC jacketing; c) fiber-reinforced polymers; d) external post-tensioned cables.

3. Life-cycle-based evaluation of strengthening techniques The life-cycle-based evaluation and comparison presented in this section aims to qualitatively assess and compare the strengthening techniques analyzed in the previous section from a sustainability-oriented perspective. Due to the lack of detailed inventory data required for a full quantitative Life Cycle Assessment (LCA), the evaluation is conducted at a qualitative level, focusing on the relative influence of each technique on the main life-cycle stages of a bridge intervention (Ko and Gonzalez 2025). The assessment is intended to support early-stage decision-making, where several retrofit alternatives provide comparable structural performance but may differ significantly in terms of material demand, construction processes, maintenance requirements, and end-of-life implications. The comparison adopts a life-cycle perspective consistent with established standards for civil engineering works (EN15643-5 2017, EN17472 2022), considering the following stages: material production (A1–A3), transport and construction/installation (A4–A5), use and maintenance (B), and end-of-life (C). Accordingly, the qualitative life cycle evaluation is performed with respect to the following criteria: (i) material efficiency, referring to the ability of each intervention to achieve the required structural performance with limited material quantities and reduced embodied impacts; (ii) construction efficiency, addressing the ease of installation, the limited invasiveness of the intervention, the need for standard equipment, and the reduced impact on traffic and serviceability; (iii) durability of the intervention, referring to the expected long-term performance of the strengthening system, its resistance to degradation mechanisms, and its ability to retain its structural function over time; (iv) ease of maintenance, considering the extent to which the intervention minimizes the need for future inspections, repairs, replacements, or re-tensioning; (v) adaptability and reversibility, related to the possibility of modifying, removing, or upgrading the intervention during the remaining service life of the bridge; and (vi) end-of-life management, addressing the ease of demolition, material separation, recyclability, and disposal associated with the strengthening system. Each criterion is discussed using relative qualitative terms (e.g., low, medium-low, medium, medium-high, high) in order to enable a comparison among the alternatives (Penadés-Plà et al. 2016). For all criteria, higher ratings indicate more favorable performance from a life-cycle perspective, while lower ratings denote less favorable performance. From a life-cycle perspective, steel jacketing is characterized by a low to moderate material efficiency, mainly due to the use of steel plates and adhesives. Although steel is recyclable, its production entails significant embodied energy, and the added permanent load may reduce overall resource efficiency. Construction operations are moderately invasive, potentially causing localized disruption. Long-term performance depends on adequate corrosion protection, which reduces its ease of maintenance over time. Reversibility is limited, and although steel can be recycled, separation from the concrete substrate may complicate end-of-life operations. Overall, steel jacketing represents a robust but materially intensive solution with moderate life-cycle performance. Reinforced concrete jacketing exhibits the highest material demand among the considered techniques, resulting in increased embodied impacts and permanent load. The construction phase is highly invasive, involving extensive on site operations and longer execution times. While the technique can provide good durability, the newly added concrete elements are themselves susceptible to ageing, potentially increasing future maintenance needs. The intervention is not reversible, and end-of-life management is unfavorable due to the complexity of demolition and material separation. As a result, reinforced concrete jacketing tends to show the lowest qualitative life-cycle performance among the analyzed techniques.