# Teaching Characteristics of Wood Biomass Fly Ash Cement Composites
## Materials and Methods
### Specimen Preparation and Testing Methods  
The leaching tests and sample labels are shown in Table 3. Labels F1, F2, and F3 represent the samples obtained from the eluates of WBA1, WBA2, and WBA3, respectively. Crushed mortar samples M1, M2, and M3 had 15% of their cement replaced with WBA1, WBA2, and WBA3, respectively, and monolithic samples M15-1, M15-2, and M15-3 had 15% of their cement replaced with WBA1, WBA2, and WBA3, respectively. REF was a monolithic sample containing only cement as a binder, while M0 designates the crushed mortar sample without WBA. The WBA leachate (F1, F2, and F3) and crushed cement mortar (M0, M1, M2, and M3) samples were tested according to the standard EN 124 57-2:2005 [71], wherein the liquid to solid phase ratio (L/S) was \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Plant** & **Plant Power (Electric** & **Combustion** & **Furnace** & **Additives Used** \\
**Designation** & **and Thermal Energy)** & **Technology** & **Temperature (°C)** & **during Combustion** \\ \hline
1 & 4.6 MWel &
\begin{tabular}{c} Grate combustor + \\ pulverized fuel \\ combustor \\ \end{tabular} & 700–750 & - \\
2 & 2.75 MWel &
\begin{tabular}{c} Grate combustor \\ \end{tabular} & 800 & - \\
3 & 15 MWth &
\begin{tabular}{c} Grate combustor \\ \end{tabular} & 850 & Quartz sand \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Plant characteristics. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Measured Values from WBA Samples**} & \multirow{2}{*}{**Cement**} & \multicolumn{2}{c}{**Values from the Literature**} \\ \cline{2-5}  & **WBA1** & **WBA2** & **WBA3** & & **Bottom WBA** & **Fly WBA** \\ \cline{2-5}  & **1850** & **314.7** & 139 & 182.4 & 15–1000 & 34–17 470 \\ Cd (mg/kg) & **3.1** & **2.6** & **6** & 0.93 & 0.4–0.7 & 1–60 \\ Cr (mg/kg) & 50 & **123** & 61.7 & 63.9 & \textless{}60 & 18–160 \\ Ni (mg/kg) & 79.6 & **170.3** & 35.2 & 68.7 & 40–250 & 20–102 \\ Pb (mg/kg) & **79.9** & **101.4** & **37.8** & 1.9 & 15–60 & 12–5318 \\ Mn (mg/kg) & **6565** & **1660** & **942** & 617.3 & 2500–5500 & 6000–9000 \\ Co (mg/kg) & **11.2** & **26** & **15.8** & 7.9 & 0–7 & 3–200 \\ Ba (mg/kg) & **588.8** & **1437** & **545** & 236.7 & / & 669–2210 \\ Bi (mg/kg) & **44.8** & _2.8_ & 25.2 & \textless{}0.02 & / & / \\ Sr (mg/kg) & 408.5 & 314.7 & 485 & 1775.4 & / & 667–1065 \\ Cu (mg/kg) & **84.4** & **79.7** & **56.1** & 30.6 & 15–300 & 27–920 \\ Hg (mg/kg) & \textless{}0.003 & 0.01 & **0.189** & 0.042 & 0.4 & 0.1–1.1 \\ HMI & 20.57 & 17.27 & 13.67 & 6.49 & / & / \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of the heavy metals content (mg/kg) in the tested wood biomass ash (WBA) and cement, with heavy metal values for fly WBA and bottom WBA from literature [7, 8, 56, 66, 67, 68, 69]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Testing Method** & **Tested Samples** & **Sample Designation after Testing** \\ \hline EN 12457-2:2005 & \begin{tabular}{c} Eluate of samples WBA1, WBA2 and WBA3 \\ Crushed mortar with 15\% of WBA replacement \\ 1, 2 and 3 and reference mixture \\ \end{tabular} & F1, F2, F3 \\ \
\begin{tabular}{c} M0, M1, M2, M3 \\ \end{tabular} \\ \hline CEN/TS 16637-2 &
\begin{tabular}{c} Monolithic samples with 15\% WBA replacement \\ 1, 2 and 3 and reference mixture \\ \end{tabular} & REF, M15-1, M15-2, M15-3 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Test programme and sample labelling. 10 for the granulated material that was exposed to the more direct action of water. The crushed mortar sample with 15% WBA was prepared according to the standard EN 196-1:2016 [72]. The composition of the mortar and storage of materials before usage followed the standard, which defines that the mass ratio of CEN components, standard sand, cement, and water is 3:1:0.5. The mortar contained \(1350\pm 5\) g of sand, \(450\pm 2\) g of cement, and \(225\pm 1\) g of water; 15% of the cement was replaced with WBA. The mortar was crushed and sieved to a particle size less than 4 mm to produce the crushed mortar samples.