# Performance of Ore Sand as Aggregate for Interlocking Blocks
## 2 Materials and Methods
### Life Cycle Assessment
#### 2.3.3 Impact Assessment  
Life cycle assessment evaluates environmental effects based on LCI data, using methods and indicators that quantify the impact in different categories. The impact assessment was performed in SimaPro software. It applied the CML 2001 method [41] and involved the following impact categories: abiotic depletion, fossil-fuel depletion, global warming, ozone depletion, potential for human toxicity, potential for freshwater aquatic ecotoxicity, potential for marine aquatic ecotoxicity, potential for terrestrial ecotoxicity, photochemical oxidation, acidification, and eutrophication.  
For the transport assessment, a scoring method (score indicator) was used. This method combines the results of the eleven impact categories obtained with the CML 2001 method into a single score, making it easier to compare the cumulative impacts across the different distances considered. The ratios between the results obtained in each impact category between the two blocks are metrics that compare the performance of the OS Block (\(V\)) to that of the conventional block (\(V_{t}\)). Higher proportions indicate a more significant difference between the products being compared. This evaluation format is commonly used in performance management, strategic planning, project evaluations, and evaluation of company goals [42].  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Process** & **Amount** & **Unit** & **Inventory Impact Data Source** \\ \hline _Ore Sand Block_ & & & \\  Gravel & 39.3 & tons & Gravel, crushed [BR]—gravel production, crushed [38]. \\  Transportation of Gravel & 7.46 (10 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\  Natural Sand & 85.1 & tons & Sand [BR]—sand-quarry operation, extraction from \\  Transportation of Natural Sand & 106.69 (66 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\ & 7.07 (50 km) & & \\ & 14.4 (100 km) & & \\  Transportation of ore sand—freight & 28.27 (200 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\  train & 56.54 (400 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\ & 113.09 (800 km) & & \\ & 226.18 (1600 km) & & \\ & 37.3 (50 km) & & \\ & 74.61(100 km) & & \\  Transportation of ore sand—freight & 149.22 (200 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\  truck & 298.43 (400 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\ & 596.86 (800 km) & & \\ & 1193.72 (1600 km) & & \\ _Conventional Block_ & & & \\  Gravel & 39.3 & tons & Gravel, crushed [BR]- gravel production, crushed [38]. \\  Transportation of Gravel & 7.46 (10 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\  Natural Sand & 98.2 & tons & Sand [BR]—sand quarry operation, extraction from \\  Transportation of Natural Sand & 123.10 (66 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\  Limestone Sand & 26.2 & tons & Gravel, crushed [BR]—gravel production, crushed [38]. \\  Transportation of Limestone Sand & 4.97 (10 km) & liters & Diesel, burned in building machine [GLO]—market [39]. \\ \hline \hline \end{tabular}  
* [BR] = data for Brazil; [GLO] = data for World.  
\end{table}
Table 2: Inventory process database for the IOT block and conventional block aggregates.  
All impact categories were given equal weight in the present analysis. The _Score Indicator_ (_SI_) is the sum of the results of relative impact for each category (\(V/V_{t}\)) for each of the systems evaluated and divided by the number of impact categories assessed (\(n\)). The equation (Equation (1)) used is shown below:  
\[SI=\frac{\sum_{1}^{n}\left(\frac{V}{V_{t}}\right)}{n} \tag{1}\]  
where \(V\) is the value (result) of the impact category obtained for each distance variation, \(V_{t}\) is the value of the impact category for the target product (e.g., conventional block), and \(n\) is the number of impact categories evaluated.