# Life Cycle Assessment of Mortars Produced Partially Replacing Cement by Treated Mining Residues
## 3 Results and Discussion
### Impacts of Constituents and Management Scenarios in Morters' Lifecycle  
Mortars are commonly composed by mineral binders, aggregates, and water [52]. In this study, only the binder was modified during mortar production, comparing with conventional manufacture. However, the impacts of mortars should gather all the involved elements in its assembly. In this sense, Figure 3 summed up the weight that mortars' components and their respective management scenarios, may have in the environmental categories analysed (based on data from Tables A1-A6, in Appendix A).  
The water used in mortar manufacture has no significant expression in the environmental categories analysed, when compared with the other components. However, it is important to notice that water is the most consumed substance on the planet. The rapid economic and population growth have increased water demand and limited water supplies, and better management measures to alleviate water scarcity are desired [53].  
The aggregate fraction (sand) demonstrated higher weight in ODP, particularly in ME10 (78%), ME25 (62%), and ME50 (46%). From the production of 1 t of mortars, a total of 2.55 \(\times\) 10\({}^{-7}\) kg CFC-11 eq. are released from sand exploration. (Table A3, in Appendix A). The extraction of alluvial material from river beds and sections present degradation risks, increasing the need to develop new strategies for the extraction quarries [54]. Raw silica sand could also be excavated from deposits in open-pit mines. However, sand shortage is also an important issue, constituting one of the greatest sustainability challenges of this  
Figure 3: Contribution of mortars’ constituents for the environmental impacts in the categories analysed: (**A**) Abiotic Depletion Potential; (**B**) Global Warming Potential; (**C**) Ozone depletion Potential; (**D**) Photochemical Ozone Creation Potential; (**E**) Acidification Potential; and (**F**) Eutrophication Potential.  
century [55]. The exploitation of silica sand for industrial application implies the removal of gangue minerals from excavated topsoil, commonly carried out in a processing plant [56]. The equipment involved on sand exploitation justify the higher ODP, when compared to the other constituents processing methods.  
The typology of the binder applied in mortars manufacture demonstrated different behaviors in mortars' overall impacts. The ED mining residues showed higher percentual representativity in POCP (53%) and ODP (52%), for ME50. Coupling the thermal treatment to mining residues contributed to 64-84% of the ODP in MET10, MET25, and MET50, and for almost 100% of the ADP. The disposal of mining residues, as a result of the reuse absence in REF, contributed to the majority of the ODP (98%), POCP (99%), and AP (90%).  
Concerning the conventional option, cement has a significant expression in ADP (almost 100% for REF, ME10, ME25, and ME50), GWP (from REF = 51% to ME10 = 97%), AP (from MET50 = 44% to ME10 = 90%), and EP (from REF = 59% to ME10 = 94%). Even when cement was replaced at 50% ratios, the impacts of mortars with treated mining residues incorporation were mainly due to the cement presence. Only the mining residues subjected to ED plus thermal treatment exceeded the cement impacts in the ADP.