## 3 Results and Discussion
### Simulating Agro-Based Materials Production
#### 3.5.1 Agro-Based Concrete Simulation--Alkaline Extraction
To further understand the material properties of hemp shiv and the effects of the extraction processes, the specific surface area of the plant material was measured using Dy  
Figure 5: Mass losses of HS1 and HS2 after simulating process extraction of “agro-based concrete” simulation. HS1 is represented in orange shades, while HS2 is represented in shades of blue. namic Vapor Sorption (DVS). The Brunauer-Emmett-Teller (BET) model was employed to analyze the specific surface area based on the sorption data obtained. The BET model helps in quantifying the surface area by fitting the experimental data to predict the monolayer adsorption capacity, which can provide a comprehensive understanding of the material's surface properties and its interaction with water. Specific surface area (\(a_{s}\))  
The specific surface area values (BET model) are presented in Table 7.  
For HS1, the specific surface areas measured under different conditions are as follows: 157.9 m\({}^{2}\)/g for the control, 171.1 m\({}^{2}\)/g for milli-Q water at 50 \({}^{\circ}\)C, 182.5 m\({}^{2}\)/g for NaOH at room temperature (RT), 172.7 m\({}^{2}\)/g for NaOH at 50 \({}^{\circ}\)C, 151.7 m\({}^{2}\)/g for Ca(OH)\({}_{2}\) at RT, and 153.3 m\({}^{2}\)/g for Ca(OH)\({}_{2}\) at 50 \({}^{\circ}\)C. The presence of NaOH tends to increase the specific surface area of HS1, while lime (Ca(OH)\({}_{2}\)) results in a slight decrease compared to the control condition at room temperature. Given that the extraction was performed on unground plant particles, it is the external surface of the particles, as well as the open pores accessible to the solvent, that interact with the extraction solvent. Overall, few significant differences were observed between the various conditions for HS1, except that the lime treatments generally resulted in a reduction in specific surface area. Heat (50 \({}^{\circ}\)C) also appears to enhance the specific surface area, likely due to the extraction process making water-soluble polar compounds more accessible. Interestingly, when considering the cumulative effects of temperature and base, the specific surface area decreases by approximately 5% for NaOH but increases by about 1% for Ca(OH)\({}_{2}\) compared to the base at room temperature. For HS2, the specific surface area values are 153.2 m\({}^{2}\)/g for the control, 145.0 m\({}^{2}\)/g for water at 50 \({}^{\circ}\)C, 173.0 m\({}^{2}\)/g for NaOH at RT, 146.1 m\({}^{2}\)/g for NaOH at 50 \({}^{\circ}\)C, 167.0 m\({}^{2}\)/g for Ca(OH)\({}_{2}\) at RT, and 153.6 m\({}^{2}\)/g for Ca(OH)\({}_{2}\) at 50 \({}^{\circ}\)C. A notable trend emerges when comparing the condition with water at 50 \({}^{\circ}\)C and the simulations carried out with a base at 50 \({}^{\circ}\)C. Interestingly, when considering the cumulative effects of temperature and base, the specific surface area decreases by approximately 15% for NaOH but increases by about 8% for Ca(OH)\({}_{2}\) compared to the base at room temperature. HS2 shows similar reaction kinetics under these conditions. This observation suggests that the effect of the base might be negligible when the temperature effect is predominant. However, in the absence of a temperature effect, a tendency for the specific surface area to increase is observed (173.0 m\({}^{2}\)/g for NaOH and 167.0 m\({}^{2}\)/g for Ca(OH)\({}_{2}\)). The type of base seems also to be an important factor since we observed those differences between HS1 and HS2. These results differ significantly from those of HS1 (182.5 m\({}^{2}\)/g for NaOH and 151.7 m\({}^{2}\)/g for Ca(OH)\({}_{2}\)), indicating that if the specific surface area of HS2 decreases during the combined base and temperature effects, HS2 may interact less with its environment compared to HS1, leading to a reduced ability to release compounds. This could be a part of the explanation about the difference in the soluble compound rate in Van Soest results between HS1 and HS2 (Table 3).