## 4 Results
### Sensitivity Analysis
From the list of materials with a high environmental impact of P2, three materials are chosen to be replaced with another material that meets the requirements specified in the contract and that provide the project with added environmental value: see Table 4.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Code** & \(\mathbf{U_{Ref}}\) & **Materials in P1** & **Weight** & **Weight** & **CF** & **CF** & **WF** & **EE** & **EE** \\  & & & **@gmj\({}^{2}\)** & **(v\%)** & **(GCog/mj)** & **(v\%)** & **(m/m2)** & **(v\%)** & **(M/jm\%)** & **(v\%)** \\ \hline CH45020 & m\({}^{3}\) & CONCRETE HM-25/P/40/1 & 2.92\(\times\)10\({}^{2}\) & 13.7 & 3.36\(\times\)10\({}^{-2}\) & 27.2 & 512\(\times\)10\({}^{-1}\) & 19.2 & 2.04\(\times\)10\({}^{2}\) & 15.9 \\ \hline UP10800 & u & PAVER VBRATED CONCREETE & 9.67\(\times\)10\({}^{1}\) & 4.5 & 2.46\(\times\)10\({}^{-2}\) & 19.9 & 2.15\(\times\)10\({}^{-1}\) & 8.1 & 1.42\(\times\)10\({}^{2}\) & 11.0 \\ \hline UA08585 & u/m & VITRIFIED CERAMIC PIECES & 2.09 \(\times\)10\({}^{1}\) & 1.0 & 1.73\(\times\)10\({}^{-2}\) & 14.0 & 3.15\(\times\)10\({}^{-1}\) & 11.8 & 3.21\(\times\)10\({}^{2}\) & 25.0 \\ \hline UP08320 & m & CURB CONCREETE & 5.19 \(\times\)10\({}^{1}\) & 2.4 & 1.49\(\times\)10\({}^{-2}\) & 12.1 & 1.83\(\times\)10\({}^{-1}\) & 6.9 & 8.74\(\times\)10\({}^{3}\) & 6.8 \\ \hline AW00100 & m\({}^{3}\) & ARTIFICAL AGREGATES & 5.77 \(\times\)10\({}^{2}\) & 27.1 & 6.40\(\times\)10\({}^{-3}\) & 5.2 & 6.93\(\times\)10\({}^{-1}\) & 25.9 & 9.26\(\times\)10\({}^{3}\) & 7.2 \\ \hline US10105 & m & DUCTILE CAST IRON & 2.66 \(\times\)10\({}^{1}\) & 0.1 & 4.33\(\times\)10\({}^{-3}\) & 3.5 & 8.13\(\times\)10\({}^{-2}\) & 3.0 & 7.37\(\times\)10\({}^{3}\) & 5.7 \\ \hline AP0100 & m\({}^{3}\) & SIFTED CHALKY SAND & 4.25 \(\times\)10\({}^{2}\) & 20.0 & 3.86\(\times\)10\({}^{-3}\) & 3.1 & 4.25\(\times\)10\({}^{-2}\) & 1.6 & 2.23\(\times\)10\({}^{3}\) & 1.7 \\ \hline \multicolumn{10}{c}{TOTAL IN PROJECT P1} & \multicolumn{1}{c}{1.47 \(\times\)10\({}^{6}\)} & \multicolumn{1}{c}{68.9} & \multicolumn{1}{c}{1.05 \(\times\)10\({}^{-1}\)} & 85.0 & 2.04 \(\times\)10\({}^{-2}\) & 76.5 & 9.43\(\times\)10\({}^{-2}\) & 73.3 \\ \multicolumn{10}{c}{**Code**} & \multicolumn{1}{c}{**U\({}_{Ref}\)**} & \multicolumn{1}{c}{**Materials in P2**} & \multicolumn{1}{c}{**Weight**} & \multicolumn{1}{c}{**CF**} & \multicolumn{1}{c}{**WF**} & \multicolumn{1}{c}{**WF**} & \multicolumn{1}{c}{**WF**} & \multicolumn{1}{c}{**EF**} \\  & & **(kg/m3)** & **Weight** & **(GCog/mj)** & **(v\%)** & **(m/m3)** & **(v\%)** & **(M/jm3)** & **(v\%)** \\ \hline UA08585 & u/m & VITRIFIED CERAMIC PIECES & 4.06 \(\times\)10\({}^{1}\) & 1.0 & 3.35\(\times\)10\({}^{-2}\) & 16.0 & 6.10 \(\times\)10\({}^{-1}\) & 8.4 & 6.23 \(\times\)10\({}^{2}\) & 18.3 \\ \hline UP0758 & u & PHOTOCATALYIC CONCREETE & 1.54 \(\times\)10\({}^{2}\) & 3.7 & 3.31\(\times\)10\({}^{-2}\) & 15.8 & 4.68 \(\times\)10\({}^{-1}\) & 6.5 & 2.31 \(\times\)10\({}^{2}\) & 6.8 \\ \hline UAUU10585 & u & URBAN FRUNTRUTE (METALLIC) & 4.31 \(\times\)10\({}^{2}\) & 0.1 & 3.27 \(\times\)10\({}^{-2}\) & 15.6 & 6.85 \(\times\)10\({}^{-1}\) & 9.5 & 5.47 \(\times\)10\({}^{2}\) & 16.1 \\ \hline CH42025 & m & MASS AND FRUNTRODE CONCREETE & 2.83 \(\times\)10\({}^{2}\) & 6.8 & 3.18\(\times\)10\({}^{-2}\) & 15.2 & 4.76 \(\times\)10\({}^{-1}\) & 6.6 & 1.75 \(\times\)10\({}^{2}\) & 5.1 \\ \hline AW00100 & m\({}^{3}\) & ARTIFICAL AGREGATES & 1.26 \(\times\)10\({}^{3}\) & 30.2 & 1.34 \(\times\)10\({}^{-2}\) & 6.4 & 1.50 \(\times\)10\({}^{2}\) & 20.7 & 1.8 The materials replaced are, in the first place, photo-catalytic concrete kerbs and pavements, which are substituted with prefabricated concrete tiles with the same physical and mechanical characteristics, in whose production recycled raw materials have been used: 72% for the pavements, and 82% for the kerbs. This substitution reduces the CF and WF by half and EE by 70%, thereby deleting its environmental significance in the project.