*4.3. Life-Cycle Assessment*

In this section, the guidance defined by ISO 14040:2006 [22] will be applied to the bridge studied. For this purpose, the different steps will be particularized to the case of study, describing and taking into account the specific characteristics considered for this study. Figure 4 show a general view of the LCA process carried out.

**Figure 4.** General scheme LCA process.

#### 4.3.1. Goal and Scope

The LCA will be divided into the four main phases of the whole life-cycle of the bridge for a better understanding: (1) manufacturing; (2) construction; (3) use and maintenance; and (4) end of life. Each phase will be defined separately and thus each phase will be limited by its own system boundary. The functional unit will be 1 m of the length of the bridge. The final goal is to find the environmental

impact of each phase and consequently the global environmental impact of the bridge by adding the environmental impacts of different phases.
