## 3 Results
### Life Cycle Impact Analysis  
Table 6 shows that Scenario 1 provides the worst environmental performance in almost all the impact categories, except for Natural land transformation and Ionizing radiation. This means that both the valorisation of GS as a substitute for feldspar (Scenario 2) and as a substitute for fine-medium inert filler in concrete mixtures (Scenario 3) bring higher environmental advantages when compared with the current practice of GS disposal in landfills (Scenario 1). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Name** & **Unit** & **Scenario 1** & **Scenario 2** & **Scenario 3** \\ \hline Human toxicity & kg 1.4 DCB eq & 6.98 & 5.64 \(\times 10^{-1}\) & \(1.93\times 10^{-1}\) \\ Particulate matter formation & kg PM10 eq & 1.24 & 1.24 & 1.24 \\ Climate change & kg CO\({}_{2}-\) eq & 8.65 \(\times 10^{-1}\) & \(-1.01\) & \(-5.20\times 10^{-1}\) \\ Fossil depletion & kg oil eq & 3.74 \(\times 10^{-1}\) & \(-4.48\times 10^{-1}\) & \(-2.05\times 10^{-1}\) \\ Freshwater cootoxicity & kg 1.4 DCB eq & 2.63 \(\times 10^{-1}\) & 1.39 \(\times 10^{-1}\) & \(1.16\times 10^{-1}\) \\ Marine cootoxicity & kg 1.4 DCB eq & 2.41 \(\times 10^{-1}\) & 1.23 \(\times 10^{-1}\) & \(1.01\times 10^{-1}\) \\ Metal depletion & kg Fe eq & 2.06 \(\times 10^{-1}\) & 1.11 \(\times 10^{-1}\) & \(7.91\times 10^{-2}\) \\ Urban land occupation & m\({}^{2}\) a & 1.28 \(\times 10^{-1}\) & \(-2.63\times 10^{-2}\) & \(-3.85\times 10^{-2}\) \\ Ionizing radiation & kg (235.9 \(\times 10^{-2}\) & \(7.23\times 10^{-2}\) & \(-4.21\times 10^{-2}\) \\ Agricultural land occupation & m\({}^{2}\) a & 7.66 \(\times 10^{-3}\) & \(-7.40\times 10^{-4}\) & \(-1.70\times 10^{-5}\) \\ Photochemical oxidant & kg NMVOC & \(5.12\times 10^{-3}\) & \(-3.07\times 10^{-3}\) & \(-4.83\times 10^{-3}\) \\ Terrrestrial acidification & kg SO\({}_{2}\) eq & \(5.06\times 10^{-3}\) & \(-1.02\times 10^{-3}\) & \(-3.65\times 10^{-3}\) \\ Water depletion & m\({}^{3}\) & \(2.48\times 10^{-3}\) & \(-1.03\times 10^{-3}\) & \(-2.70\times 10^{-4}\) \\ Marine eutrophication & kg N eq & \(1.64\times 10^{-3}\) & \(-8.30\times 10^{-4}\) & \(-1.53\times 10^{-3}\) \\ Freshwater eutrophication & kg P eq & \(5.30\times 10^{-4}\) & \(3.20\times 10^{-4}\) & \(31.33\times 10^{-5}\) \\ Terrestrial cootoxicity & kg 1.4 DCB eq & \(3.40\times 10^{-4}\) & \(6.64\times 10^{-5}\) & \(-4.72\times 10^{-5}\) \\ Ozone depletion & kg CFC-11 eq & \(1.54\times 10^{-2}\) & \(-1.53\times 10^{-7}\) & \(-9.96\times 10^{-8}\) \\ Natural land transformation & m\({}^{2}\) & \(-1.49\times 10^{-3}\) & \(1.23\times 10^{-8}\) & \(-1.10\times 10^{-4}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Environmental impacts calculated according to the ReCiPe Midpoint (H) method for Scenario 1 (GS disposal in landfills), Scenario 2 (GS valorised as a substitute for feldspar in ceramic materials), Scenario 3 (GS valorised as a substitute for fine-medium inert filler in concrete mix). Yellow cells indicate the highest values, and light green are the lowest values obtained for each impact category, respectively. All values are referred to the functional unit 1 m\({}^{2}\) granite slab. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sample** & **Wc** & **Density** & \multicolumn{2}{c}{**Compressive Strength**} & \multicolumn{2}{c}{**Compressive Strength**} & \multirow{2}{*}{**Slump**} & \multirow{2}{*}{**Reference**} \\ \cline{5-6}  & & & 24 h & 7 d & 28 d & 28 d & & \\ \hline \hline \multirow{2}{*}{} & - & kg/m\({}^{3}\) & & mPa & & \% & mm & \\ \hline Concrete 5\% GS & 0.56 & 2383 & 13.8 & 35.8 & 40.8 & \(-10\%\) & 180 & This work \\ Concrete & 0.52 & 2408 & 13.7 & 39.1 & 45.1 & Reference & 190 & Standard \\ C30/37.S4.D22.CI0,40 & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of Water: Cement ratio (W:C), apparent density, compressive strength, compressive strength decrease, and slump of concrete 5% GS with standard structural Concrete C30/37.S4.D22.CI0,40.