# Performance of Ore Sand as Aggregate for Interlocking Blocks
## 5 Conclusions  
Based on the objectives set and the findings of this research, the following conclusions can be drawn:  
* The OS block has similar strength performance compared to the conventional block, meeting the established standard of 35 MPa.
* Ore sand is an environmentally sustainable alternative for use in the replacement of conventional aggregates used for the production of interlocked blocks. This study found an average reduction of 30% for the 11 impact categories compared to the traditional block.  
Figure 12: Potential distribution of ore sand for use in producing an environmentally friendly block (map created using QGIS software v3.14 [63] and data from IBGE [64]).  
* The transportation of conventional aggregates has a significant impact on the production of both blocks. It represents an average of 23.7% of the total impact for the ordinary block and 26% for the block produced with ore sand.
* Using the scoring indicator (SI), it was possible to establish that the transportation of ore sand for distances of 1147 km by rail and 217 km by road results in the same environmental impact for the ore-sand block as for the conventional block.
* Transportation distances shorter than those above make the block with ore sand more environmentally friendly than the conventional alternative. Over these distances, it is possible to reach other states in Brazil, as well as many cities (mostly inside the state of Minas Gerais) around the mining area that can supply other interlocking paving block factories.
* The LCA technique in association with \(SI\) proved to be a useful decision-making tool in defining the transport distance that makes it possible to manufacture an environmentally responsible block.  
Within the limits set, this work offers an innovative LCA-based approach to evaluating the environmental performance of interlocking paving blocks constructed with ore sand as an aggregate and the limiting effects of transportation on their production. The incorporation of ore sand into the interlocking paving block confers environmental benefits to the product, increasing the environmental sustainability of the industry. The method presented can be adapted to different locations, allowing the determination of an environmentally safe distance between the tailings-generation site and the production sector.  
Conceptualization, R.B.S., M.F.L.M., R.J.B. and N.C.C.; methodology, R.B.S., M.F.L.M., R.J.B. and N.C.C.; validation, R.B.S. and M.F.L.M.; formal analysis, R.B.S. and M.F.L.M.; investigation, R.B.S. and M.F.L.M.; data curation, R.B.S. and M.F.L.M.; writing--original draft preparation, R.B.S., M.F.L.M., R.J.B. and N.C.C.; writing--review and editing, R.B.S., M.F.L.M., R.J.B. and N.C.C.; supervision, N.C.C.; project administration, N.C.C.; funding acquisition, N.C.C. All authors have read and agreed to the published version of the manuscript.  
The authors wish to make explicit their appreciation to VALE S.A. (IAP-001247 and IAP-001466) and CNPq (Brazilian Research Council) for the support to the research group.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to ethical considerations and potential future publications.  
The authors declare that this study received funding from VALE S.A. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.