## 5 Analysis of Life Cycle Assessment Results  
The results obtained in the life cycle assessment begin with the comparison of the different alternatives generated by the different provisions to observe the percentage impact of each variant previously studied in the reinforcement of the transition zones. These results are presented in Table 7, where reference is made to each sustainability indicator. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Environmental Indicators** & **Units** & **LCIA Methods** \\ \hline
**Global warming (GWP 100)** & [Kg CO\({}_{2}\) eq] & CML-IA baseline V3.04/EU25+3, 2000 \\
**Ozone depletion (ODP)** & [Kg CFC \(-\) 11 eq] & CML-IA baseline V3.04/EU25+3, 2000 \\
**Potential acidification (AP)** & [Kg SO\({}_{2}\) eq] & CML-IA baseline V3.04/EU25+3, 2000 \\
**Potential eutrophication (EP)** & [Kg PO\({}_{4}\) eq] & CML-IA baseline V3.04/EU25+3, 2000 \\
**Photochemical ozone creation (POCP)** & [Kg C\({}_{2}\)H\({}_{4}\) eq] & CML-IA baseline V3.04/EU25+3, 2000 \\
**Abiotic depletion potential of fossil resources (ADP\_FF)** & [M] eq] & Cumulative energy demand V1.08 \\
**Depletion of abiotic soil and water resources (ERA)** & [Kg Sb eq] & CML-IA baseline V3.04/EU25+3, 2000 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Indicators, units, and methods of quantification. Taking into consideration the environmental impact of traditional and non-traditional solutions in Table 7, one can determine a higher ozone depletion in the recurring solutions, i.e., when implementing the transition wedges as a solution alternative, thus producing an increase in the amount of ultraviolet radiation that passes through to the earth's surface. However, when analyzing the solutions implementing RCD, it can be determined that they present lower and similar values to each other. Therefore, it is determined that the use of waste as an alternative reinforcement directly affects the environmental impacts, reducing the environmental effects due to the construction sector. Based on Table 7, it can be concluded that by implementing a large amount of BB sleepers, a decrease in the percentage of photochemical ozone production occurs, safeguarding human health, ecosystems, and agriculture, thus obtaining considerably lower values. The results obtained in the life cycle assessment (Table 7) were normalized to analyze and compare the environmental impact according to Equation (1). The normalized results are shown in Table 8 for each arrangement. Furthermore, based on a comparison of the normalized data (Table 8), the construction of transition wedges as structures to solve problems such as variations in the vertical stiffness of the track, displacements, and rotations of the bridge deck, as well as differential settlements in the transition zones, affects and damages the environment considerably, thus generating more significant environmental impacts and preventing this from being the most sustainable alternative. In contrast, BB sleepers are renowned as alternatives that can reduce environmental impacts, solving problems of stiffness variation and differential settlements in transition zones. The BB sleepers, based on the results obtained, are environmentally friendly solution alternatives and, regardless of the adopted layout, are more sustainable. The use of non-traditional solutions with the implementation of BB sleepers as reinforcement RCD led to a decrease in environmental impacts when compared to current solutions such as transition wedges, regardless of the percentage of raw material substitution, i.e., soil implemented for each layer of the landfill and the amount of RCD. The results also showed that the values for the provisions with a higher amount of BB sleepers presented a better alternative in a way that is more efficient from a technical, economic, and environmental point of view. At this stage, it is necessary to highlight the effect of the attribution step of the results obtained.