PSI - Issue 84

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

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Overall, the combined analysis of structural efficiency and costs highlights that strengthening techniques achieving similar performance targets may differ significantly in terms of economic convenience, further supporting the need for integrated comparative frameworks.

Fig. 3. Comparison of the cost index for the analyzed strengthening techniques (*FRP results refer to the achieved capacity increase).

5. Integrated discussion The integrated ordinal comparison reported in Table 2 shows that strengthening techniques achieving similar performance target may differ substantially when structural efficiency, cost-effectiveness, and qualitative life-cycle performance are jointly considered. External post-tensioning consistently ranks first across all three criteria, confirming its balanced behavior and its suitability as a comprehensive retrofit solution. This outcome reflects its high structural efficiency, favorable cost-to-performance ratio, and advantageous life-cycle characteristics. Steel jacketing occupies an intermediate position, ranking second for all dimensions. This confirms its technical reliability, while also highlighting limitations related to relatively high material demand, moderate construction efficiency, and reduced adaptability. Traditional jacketing techniques may therefore remain preferable for localized interventions. FRP-based retrofits show a heterogeneous performance profile. Despite favorable life-cycle characteristics associated with low added weight and limited construction invasiveness, their structural and economic rankings are less favorable. This is mainly due to bond-governed failure mechanisms limiting the achievable strength increase, as well as to the relatively high cost of composite materials. Reinforced concrete jacketing consistently ranks last in the integrated comparison, being penalized by high material demand, significant added permanent load, limited reversibility, and unfavorable end-of-life scenarios. Overall, the integrated ranking confirms that retrofit strategies should be selected through a multi-criteria perspective, explicitly accounting for economic and life-cycle-oriented aspects in addition to structural performance. Table 2. Ordinal ranking of strengthening techniques based on qualitative LCA, structural efficiency, and cost-effectiveness. Intervention LCA-based performance Structural efficiency Cost effectiveness Overall rank External post-tension 1° 1° 1° 1° Steel jacketing 2° 2° 2° 2° FRP retrofit 2° 2° 4° 3° RC jacketing 3° 3° 3° 4° 6. Conclusions This work proposed an integrated life-cycle-based evaluation for the comparative assessment of the most used strengthening strategies for prestressed reinforced concrete bridge girders, aimed at supporting early-stage decision-