## 2 Experimental Details
### Mix Proportions and Casting of Specimens  
In previous concrete, cementitious materials are mainly used to properly coat and bond aggregates. It was found that the property of the cementitious material and its coating thickness are key factors in evaluating the structural and hydrological properties of the PC [58]. In this study, three matrixes with polypropylene fibers in different mix proportions were selected, as shown in Table 6. Once the matrix was mixed, the fresh properties of the mixture were measured and recorded. Then, matrix specimens (50 \(\times\) 50 \(\times\) 50 mm cube) for the compressive strength test were cast from each mixture. On the other hand, Table 7 shows the mix proportions of the LPC. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Designation**} & \multirow{2}{*}{**W/B**} & **W** & **C** & **SF** & **USP** & **SP** & **VA** & **PP** \\  & & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** & **(kg/m\({}^{\text{3}}\))** \\ \hline CM1 & 0.28 & 425.99 & 1459.37 & 99.50 & 99.50 & 31.70 & 6.65 & 0.90 \\ CM2 & 0.28 & 450.24 & 1673.75 & 0.00 & 0.00 & 16.74 & 1.67 & 0.23 \\ CM3 & 0.31 & 459.29 & 1457.65 & 63.38 & 63.38 & 30.28 & 1.59 & 0.45 \\ \hline \hline \end{tabular}  
* Notes: W/B, water-to-binder ratio; W, water; C, cement; SF, silica fume; USP, ultra-fine silica powder; SP, superplasticizers; VA, viscous agent; PP, polypropylene fiber.  
\end{table} 
Table 6: The mix proportions of the matrix. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Experimental Control Factor**} & \multicolumn{3}{c}{**Levels of Experimental Control Factor**} & **Performance** \\ \cline{2-5}  & **1** & **2** & **3** & **Parameter** \\ \hline Coarse aggregate size, A (mm) & 4.75–9.5 & 9.5–12.5 & 12.5–19.0 & Compressive strength (MPa) \\ Fine aggregate content, B (\%) & 0 & 5 & 10 & Elastic modulus (MPa) \\ Matrix type, C & CM1 & CM2 & CM3 & Flexural strength (MPa) \\ Aggregate-to-binder ratio, D & High & Medium & Low & Splitting tensile strength (MPa) \\ \hline \hline \end{tabular}  
* Notes: CM1, CS:F:USP = 8.8:0.6:0.6; CM2, CS:F:USP = 10:0; CM3, CS:F:USP = 9.2:0.4:0.4.  
\end{table} 
Table 4: The parameters and design levels for the LPC. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Designation**} & \multicolumn{3}{c}{**Experimental Control Factor (Level)**} \\ \cline{2-5}  & **Coarse Aggregate Size** & **Fine Aggregate** & **Matrix Type** & **Aggregate-to-Binder** \\  & **(mm)** & **Content (\%)** & **Ratio (Weight Ratio)** \\ \hline LC1 & 4.75–9.5 (1) & 0 (1) & C:SF:USP = 8.8:0.6:0.6 (1) & 6.2 (1) \\ LC2 & 4.75–9.5 (1) & 5 (2) & C:SF:USP = 10:0 (2) & 5.9 (2) \\ LC3 & 4.75–9.5 (1) & 10 (3) & C:SF:USP = 9.2:0.4:0.4 (3) & 5.6 (3) \\ LC4 & 9.5–12.5 (2) & 0 (1) & C:SF:USP = 10:0 (2) & 5.6 (3) \\ LC5 & 9.5–12.5 (2) & 5 (2) & C:SF:USP = 9.2:0.4:0 (3) & 6.2 (1) \\ LC6 & 9.5–12.5 (2) & 10 (3) & C:SF:USP = 8.8:0.6:0.6 (1) & 5.9 (2) \\ LC7 & 12.5–19 (3) & 0 (1) & C:SF:USP = 9.2:0.4:0.4 (3) & 5.9 (2) \\ LC8 & 12.5–19 (3) & 5 (2) & C:SF:SFP = 8.8:0.6:0.6 (1) & 5.6 (3) \\ LC9 & 12.5–19 (3) & 10 (3) & C:SF:USP = 10:0 (2) & 6.2 (1) \\ \hline \hline \end{tabular}  
* Note: The numbers in parentheses indicate the level of the factor.  
\end{table} 
Table 5: The \(L_{9}\)(3\({}^{\text{4}}\)) orthogonal array for the LPC. Prior to mixing the fiber-reinforced LPC, the aggregates were first processed into the required saturated surface-dry condition. During the mixing process, the cementitious material and the aggregate were mixed evenly, and then the water, superplasticizers, and the viscous agent were added. After being fully mixed, the LPC specimens of each test were cast and compacted with an external vibrator. The compressive strength and elastic modulus of the concrete were tested using cylindrical specimens with a diameter of 100 mm and a height of 200 mm.