# Effective Mechanical Properties of a Composite Material Reinforced by Oil Shale Ash Particles
## 2 Materials and Methods
### Preparation of the Composite Concrete-OSA Specim  
For the testing of the concrete specimens, 3 groups of specimens were made according to their strength. Dimensions of the specimen are shown in Figure 3.  
Group A had a compressive strength from 72 to 64 MPa, Group B had a compressive strength from 51.8 to 37.7 MPa, and Group C had a compressive strength from 16.7 to 15.5 MPa. In Group A, specimens were made with 0%, 25%, and 30% of OSA by weight. In Group B, specimens were made with 0%, 10%, 25%, 25%, 30%, and 35% of OSA by weight. In Group C, specimens were made with 0%, 10%, 15%, 20%, 25%, 30%, and 35% of OSA by weight. Detailed information about the compositions of the samples is shown in Table 4 (Group A), Table 5 (Group B), and Table 6 (Group C).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**Group A**} & \\ \hline
**Ingredients** & **A0** & **A25** & **A30** \\ \hline Cement, 42.5 & 6.16 & 4.62 & 4.31 \\ OSA & - (0\%) & 1.54 (25\%) & 1.85 (30\%) \\ Water & 3.2 & 3.22 & 3.25 \\ Crushed stone, 4–8 mm & 23 & 23 & 23 \\ Sand, 0.3–2.5 mm & 13.2 & 13.3 & 13.5 \\ Sand, 0–1.0 mm & 2.3 & 2.5 & 2.5 \\ Dolomite sand & 2.1 & 1.8 & 1.6 \\ Plasticizer & 0.09 & 0.16 & 0.22 \\ Microsilica & 0.55 & 0.55 & 0.55 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Recipes for Group A.  
Figure 3: Drawing of an LVS EN 12390-3:2019 specimen.  
The dry concrete elements were mixed in a drum concrete mixer. The lid of the mixer was closed to maintain the correct concentration of the mixture. After adding all the ingredients according to the recipe, water was added to the concrete mixer. The composite concrete-OSA specimens (cubes) were made according to LVS EN 12390-3:2019 with dimensions of 100 \(\times\) 100 \(\times\) 100 mm (Figure 3). To find the modulus of elasticity, Clause 6.2.3.1 of the IS 456:2000 standard was used; based on the known value of the compressive strength, the compressive modulus of elasticity could be obtained. All specimens were aged for 28 days before testing. The specimen mold and shape are shown in Figure 4.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Group C**} \\ \hline
**Ingredients** & **C0** & **C10** & **C15** & **C20** & **C25** & **C30** & **C35** \\ \hline Cement, 42.5 & 5.5 & 4.95 & 4.675 & 4.4 & 4.125 & 3.85 & 3.575 \\ OSA & - (0\%) & 0.55 (10\%) & 0.825 (15\%) & 1.1 (20\%) & 1.375 (25\%) & 1.65 (30\%) & 1.925 (35\%) \\ Water & 5 & 5 & 5 & 5 & 5 & 5 & 5 \\ Crushed stone, 4-8 mm & 1.2 & 1.2 & 1.2 & 1.2 & 1.2 & 1.2 & 1.2 \\ Sand, 0.3–2.5 mm & 21 & 21 & 21 & 21 & 21 & 21 & 21 \\ Sand, 0–1.0 mm & 12.6 & 12.6 & 12.6 & 12.6 & 12.6 & 12.6 & 12.6 \\ Dolomite sand & 4.8 & 4.8 & 4.8 & 4.8 & 4.8 & 4.8 & 4.8 \\ Plasticizer & 0.14 & 0.14 & 0.14 & 0.14 & 0.14 & 0.14 & 0.14 \\ Microsilica & 0.3 & 0.3 & 0.3 & 0.3 & 0.3 & 0.3 & 0.3 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Recipes for Group C.  
Figure 4: Preparation of the composite concrete–OSA samples: (**a**) molding shape for cubic sample preparation; (**b**) composite concrete–OSA testing specimen.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**Group B**} \\ \hline
**Ingredients** & **B0** & **B30** & **B35** \\ \hline Cement, 42.5 & 6.16 & 4.31 & 4 \\ OSA & - (0\%) & 1.85 (30\%) & 2.16 (35\%) \\ Water & 3.4 & 3.4 & 3.4 \\ Crushed stone, 4–8 mm & 16 & 16 & 16 \\ Sand, 0.3–2.5 mm & 16.2 & 16.2 & 16.2 \\ Sand, 0–1.0 mm & 4.4 & 4.4 & 4.4 \\ Dolomite sand & 2.9 & 2.9 & 2.9 \\ Plasticizer & 0.225 & 0.225 & 0.225 \\ Microsilica & 0.65 & 0.65 & 0.65 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Recipes for Group B.