## 3 Results and Discussion
### Total Environmental Impact of Each Life Cycle Stage  
After the evaluation of the environmental impact of 1 kg of material, referring to the drying and milling of the waste and its comparison with other materials, and 1 m\({}^{3}\) of constructed slab for comparison with the laboratory examinations, it was necessary to evaluate the total impact referring to the fabrication of all slabs of the bridge proposal. This  
Figure 16: Chloride diffusion coefficient versus environmental impact. Figure 17: Total impact and relationships with compressive strength and service life. analysis was performed to compare the results with the construction, use, and maintenance for a 100-year horizon for the technical proposal for the Third Bridge VIXBR. The results for the fabrication of the slab for the entire bridge and the installation environmental impact for 100 years of inspections and repairs are shown in Figure 18.  
The highest environmental impacts refer to the material fabrication phase. These results agree with the finding of [PERSON] et al. [30], who performed an LCA on a standard bridge, with the following stages: material stage (extraction of raw material, production and distribution), construction, use and maintenance, and end of life. The results showed that the main contributor to environmental impact was the material production phase, accounting for 64% of the total results. The results of this research also corroborate with [PERSON] and [PERSON] [33] in which an LCA on railway bridges was performed. The authors concluded that the initial stage of manufacturing the material is responsible for the most significant environmental demand. The present study found that the control mixture presented a manufacturing-related impact of 55% (Figure 19). Figure 18: _Cont._  
When considering the total environmental impact for the fabrication of the solution and not only the analysis of 1 m\({}^{3}\) of the constructed slab, the differences among the environmental impact methodologies became less perceptible, which indicates a similarity among the results. Additionally, the environmental impact related to the maintenance and repair for 100 years was around 80% of the fabrication cost for the concrete reference solution and up to 15% for partial substitution of 20% of the milled waste (GP2-20) according to Figure 14C and the methodology IMPACT 20002+, totaling a reduction of 65% of the environmental impact. It is possible to reduce the environmental impact related to global warming (GWP) for the manufacture of materials using GP2-20 (Figure 14A) by 163,090 kg CO\({}_{2}\) eq. For 100 years, we would have 1630.9 kg CO\({}_{2}\) eq. per year. According to [PERSON] et al. [72], the production of 1000 kg clinker can generate 800 kg CO\({}_{2}\) eq. In 100 years, cement replacement by glass powder could offset the production of about 204 tonnes of clinker for cement  
Figure 19: Total endpoint environmental impact in 100 years. Figure 18: (**A**) Total GWP in 100 years; (**B**) embodied energy in 100 years; (**C**) total impact in 100 years. manufacture. According to [PERSON] et al. [72], the CEM III/ A 42.5 cement, equivalent to the Brazilian CPIII (ABNT NBR 16697 [73]) contains 47% clinker and 45% blast furnace slag, which could reduce clinker production in 400 tons of cement. Regarding the impact related to the repair activities, the reference concrete showed that around 60% of the total are related to the manufacturing impacts. On the other hand, for GP2-20, 11% of the repair impacts are related to material fabrication. This difference represents a reduction of 49% and 614,140 kg CO\({}_{2}\) eq. Considering the same understanding related to manufacturing, we would have around 768 tons of clinker production avoided. Adding up the manufacturing and repair impacts, a total of 972 tons of clinker production would be avoided. Hence, the environmental impacts referring to material milling would not have adverse effects on the environmental impact.