## 3 Materials and Methods
### Implementation of Life Cycle Assessment  
The LCCA includes construction, preventive maintenance, and end-of-life (EoL) costs. Construction costs cover the supply of materials, equipment and machinery usage, labor, and minor tools. For the CJ alternative, this also includes the cost of the recoverable formwork system. Preventive maintenance costs encompass anti-carbonation paint for CJ  
Figure 2: Alternative reinforcement schemes. (**a**) CJ and SCJ; **(b)** STE; **(c)** STA; **(d)** CFRP. and SCJ, anti-corrosion paint for STE and STA, fireproof mortar for STE, STA, and CFRP, and decennial maintenance for the first 10 years. EoL costs involve demolition, sorting, and transportation to recycling plants or landfills as appropriate. Future costs are converted to present value using a 2% social discount rate, which aligns with long-term sustainability objectives [41]. The LCCA used unit price analyses from the CYPE construction cost database, which included specific costs for Ecuador with a cutoff date of January 2025. The environmental and social dimensions are evaluated across four distinct phases. First, the objective and scope of the study are to assess five seismic retrofitting alternatives for reinforced concrete beams with shear deficiencies. The functional unit is the seismic retrofitting of a specific reinforced concrete beam, ensuring structural safety over a 50-year service life. A cradle-to-grave approach is adopted, covering material fabrication, transportation to the site, construction, preventive maintenance, and end-of-life. The end-of-life stage includes pre-treatment of concrete, transporting steel and concrete to recycling plants, and final disposal of CFRP to a landfill. The second phase consisted of conducting an inventory analysis for each alternative. Environmental impacts were assessed using the Ecoinvent database, while social impacts were assessed using SOCA v2, with both analyses modeled in OpenLCA version 2.3 software. By using SOCA, which integrates data from the PSIICA social database, the same processes applied in the environmental impact assessment were used, ensuring consistency in the results. As the global SOCA data are complete but region-specific data may be missing, the global average was used for process modeling, following the reference recommendation [42]. The energy required for machinery operations during construction was obtained from the BEDEC database. For the SCJ alternative, the additional energy required for shotcrete application was considered and extracted from BEDEC. For the STA alternative, the energy values for machinery operations during construction were adapted from reference [43]. For carbon fiber, the energy results for virgin carbon fiber production from reference [44] were adapted to Ecoinvent's carbon fiber reinforced plastic process used in aircraft manufacturing. Table 2 presents the inventory by functional unit and the associated processes from the Ecoinvent database, which were also used in SOCA. A zero discount rate was applied for future end-of-life quantifications. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Process** & **Quantity** & **Unit** & **Ecoinvent Process** \\ \hline Concrete Jacketing (CJ) & & & \\ Concrete & 0.27 & m\({}^{3}\) & Concrete, 24–30 MPa \\ Reinforcement steel & 32.83 & kg & Reinforcing steel \\ Structural adhesive & 5.69 & kg & Epoxy resin \\ Column jacketing & 462.82 & MJ & Diesel, burned in building machine \({}^{\text{a}}\) \\ Anti-carbonation paint & 1.44 & kg & Epoxy resin \\ Retrofit demolition & 64.96 & MJ & Diesel, burned in building machine \({}^{\text{a}}\) \\ Concrete crushing & 545.13 & kg & Rock crushing \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Life cycle inventory. In the third phase, the Endpoint Recipe method was employed to assess environmental impacts. At the same time, the Social Impact Weighting Methodology (MISP) was used to evaluate social impacts, and both models were modeled using OpenLCA software.