# Cleaner Design and Production of Lightweight Aggregates (LWAs) to Use in Agronomic Application
## 3 Results and Discussion
### Sintered Materials
#### 3.2.3 Mercury Intrusion Porosimetry (MIP)  
The pore volume distribution as a function of their diameter for the aggregates obtained is shown in Figures 4 and 5. The WBC aggregates obtained without the addition of waste were characterized by a multimodal pore diameter distribution with maxima \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Parameters** & **WBC** & **WBBS\({}_{\text{15}}\)** & **WB\({}_{\text{FG}}\)** & **WB\({}_{\text{CBA}}\)** & **RC** & **RCBS\({}_{\text{15}}\)** & **RC\({}_{\text{FG}}\)** & **RC\({}_{\text{CBA}}\)** \\ \hline pH & 9.21 & 7.42 & 6.98 & 8.00 & 7.16 & 7.28 & 6.71 & 7.15 \\ EC (mS/cm) & 3.24 & 1.74 & 1.12 & 1.98 & 1.15 & 1.57 & 0.72 & 1.09 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Chemical properties of LWAs sintered at 1000 \({}^{\circ}\)C compared to WBC (30% white clay–70% black clay) and RC samples containing clays only. Figure 3: LWAs—SEM micrographs (600\(\times\)) of (**a**) WBC, (**b**) RC, (**c**) WBBS\({}_{\text{15}}\), (**d**) RCBS\({}_{\text{15}}\), (**e**) WB\({}_{\text{FG}}\), (**f**) RC\({}_{\text{FG}}\), (**g**) WB\({}_{\text{CBA}}\), and (**h**) RC\({}_{\text{CBA}}\) fired at 1000 \({}^{\circ}\)C.  
between 1000 and 3000 nm. In contrary, RC-derived aggregates showed a monomodal pore diameter distribution with a maximum value at 438 nm. The addition of 15 wt % of BS generated greater porosity and a displacement of the size of the pore towards greater diameters [20,27]. It can be seen that the different pore diameters were in the interval of 100-30,000 nm for WBBS\({}_{15}\) and 30-30,000 nm for RCBS\({}_{15}\). The addition of FG glass or CBA ash did not show any variation in the range of pore diameters with respect to aggregates obtained exclusively with BS. According to those shown in Table 5 the values of open porosity (Po), total intrusion volume (TIV), and total pore area (TPA) of the manufactured aggregates. It can be seen how the volume of Hg introduced into the samples increased with the addition of BS, which  
Figure 4: Pore size distributions from mercury intrusion analysis for WBC, WBBS\({}_{15}\), WBFG, and WBCRBA aggregates. Figure 5: Pore size distributions from mercury intrusion analysis for RC, RCBS\({}_{15}\), RCFG, and RCCRBA aggregates. once again highlights the pore-generating nature of the beer industry waste used. The trend observed in the TIV values was in accordance with the values obtained for the open porosity and WA\({}_{24}\) of the aggregates. Figure 6 shows the relationship between open porosity and water absorption for the two series of aggregates studied. The behavior of both series was similar. The addition of BS produced a considerable increase in the open porosity in the aggregate associated with an increase in the water absorption value. Both parameters acquired the highest values for aggregates manufactured only with clay and this waste (WA\({}_{24}\) = 40.29% and Po = 54.78% for the WCB series; WA\({}_{24}\) = 19.01% and Po = 39.19% for the RC series). However, the vitrification capacity of the mixtures with FG generated the sealing of the superficial material layer, favoring the capacity of swelling, and creating larger pores and lower water absorption capacity [9]. As has been previously observed, the addition of FG caused the descent of porosity in almost 10.00%, which was also related to the water absorption capacity. It can also be seen that the differences in the WA\({}_{24}\) and Po values of the two clay-based mixtures, WBC and RC, were very substantial. The mineralogical composition of the clays (Table 4) showed that WC and BC had calcite (\(CaCO_{3}\)) as the majority phase and dolomite (\(CaMg(CO_{3})_{2}\)) as the minority phase. These calcium and magnesium carbonates undergo a process of thermal decomposition. The temperature at which this phenomenon occurs depends on the chemical composition.