## 4 Results
### Aggregate Characterization
Additionally, _Method of Test for Freezing and Thawing (F-T) of Aggregate_ suggests that an aggregate with excellent freeze-thaw (F-T) resistance typically experiences mass loss ranging from 4% to 18% before and after the test. It is worth noting that the fine stockpiled BOF slag demonstrated excellent sulfate and freeze-thaw resistance. However, it is important to highlight that it also possessed a higher absorption capacity and moisture content when compared to river sand. In general, it can be seen that BOF slag may vary from batch to batch. Several factors can contribute to this batch-to-batch variability, including:  
* The composition of the raw materials used in the BOF process can fluctuate. Variations in the composition of iron ore, scrap metal, and other inputs can lead to differences in the resulting slag. * Factors like temperature, pressure, and reaction kinetics during the BOF process can impact the characteristics of the slag. Variations in these conditions from one production run to another can result in different slag properties. * The cooling rate and post-production processing of the slag can influence its structure and properties. Different cooling rates or processing methods can lead to variations in the final product. * Complex chemical reactions can occur during the formation of slag. These reactions may be influenced by impurities, additives, or other factors, leading to batch-to-batch differences. * Environmental conditions, such as humidity and exposure to external elements, can affect the properties of slag materials, especially when they are stockpiled or stored for extended periods. * Quality control measures and practices within the manufacturing or processing facility can impact the consistency of slag products. Variations in quality control procedures can result in batch-to-batch differences. The aggregate crushing value (ACV) indicates satisfactory resistance to crushing under the roller during construction and adequate resistance to surface abrasion under traffic. It was found that the ACV in the fresh BOFS was equal to 32.7, whereas the ACV in the stockpiled BOFS was equal to 30.9. However, it is suggested that fresh coarse BOFS is more porous than other aggregates, which is supported by its high water absorption capacity. As previously stated, the weathering (aging) process converts hydrated calcium silicate, free lime, and calcium hydroxide (Ca(OH)\({}_{2}\)) into calcium carbonate (CaCO\({}_{3}\)) by reaction with CO\({}_{2}\). The formed calcite is stronger than Ca(OH)\({}_{2}\) and fills out the inherent voids in fresh BOFS. As a result, the stockpiled BOFS has higher strength and denser structure than the fresh BOFS. The Los Angeles aggregate abrasion value indicates the toughness and durability of aggregate subjected to impact and abrasion (Table 4). This value can provide insight into how aggregates will stand up to wear and tear over time when the aggregate is used for each construction application. Aggregates with low LA abrasion values are stronger and more resistant to abrasion. As can be seen, fresh BOFS has the highest abrasion value (percent loss) than other stockpiled BOFS. Thus, stockpiled BOFS has better toughness and abrasive properties. As stated earlier, fresh BOFS is more porous than other aggregates, which is supported by its high water absorption capacity. Also, the weathering (aging) process and hydration in \begin{table}
\begin{tabular}{c c} \hline \hline
**BOF Type** & **Percent Loss (\%)** \\ \hline Fresh BOFS & 38.7 \\ Stockpiled BOFS & 26 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: LA aggregate abrasion results of BOF slags. fresh BOFS produce CaCO\({}_{3}\), which fills out the inherent voids in fresh BOFS and produces calcium silicate hydrate (C-S-H). This result matches the aggregate crushing value result. This finding aligns with the observations of reduced porosity, improved density, and strength resulting from the aging process and the formation of CaCO\({}_{3}\).