Endpoint Approach

Despite the large amount of information obtained by means of the midpoint approach, it is very difficult to obtain a global environmental impact assessment. For this purpose, the endpoint approach is more useful. This approach provides only three damage categories (human health, resources and

ecosystem), which are easier to interpret. Table 4 shows the mean and coefficient of variance of the three damage categories. Although the reference unit of the different damage categories remains different, carrying out the normalization and weighting of three categories is easier than doing so for 18 categories. In fact, ReCiPe allows the normalization of the three damage categories by converting the reference unit of each damage category into points. That makes it easier to interpret the global environment assessment of the bridge. Figure 11 shows the normalized value of each damage category of the whole life-cycle of the bridge and Figure 12 displays the contribution of each phase considering that the different damage categories have the same importance. On one hand, Figure 11 shows that human health is the most important damage category, followed by resources and ecosystem. On the other hand, in Figure 12 the contribution of different phases using the endpoint approach can be seen. The manufacturing phase is the phase with the highest contribution to the bridge life-cycle, followed by the use and maintenance phase and both the construction phase and the end-of-life phase make very low contributions compared to the other two phases.

**Table 4.** Endpoint approach.


**Figure 11.** Damage categories.

**Figure 12.** Contribution of bridge life-cycle phases.
