## 2 Experimental Details
### Test Methods and Data Analysis  
The matrix rheology test was performed using a Brookfield HBDV-II+Mode viscometer (Middleboro, MA, USA) with a disk-type spindle (#HB04). The matrix fluidity test was based on ASTM C230 [59] and the matrix compressive strength test complied with ASTM C109 [60]. According to ASTM C1688, ASTM C1701, ASTM C39, ASTM C469, ASTM C496, and ASTM C78 [61; 62; 63; 64; 65; 66], the void content, penetration rate, compressive strength, modulus of elasticity, split tensile strength, and flexural strength of concrete specimens were respectively measured.  
In [PERSON]'s experimental design method, the deviation of the experimental value from the expected value was calculated by the so-called loss function. The value of this loss function is usually converted to a signal-to-noise ratio (S/N) [67]. The signal-to-noise ratio (n) is expressed in decibels (dB) and can be defined by the logarithm of the mean square deviation (MSD) around the target value. Performance characteristics can generally be divided into three categories: higher is better, nominal is best, and lower is better. In order to obtain a lightweight PC with high strength, the observed values of various mechanical properties were set to a maximum level. The S/N ratio was calculated according to the following equation [67]:  
\[\eta=-10\times\log_{10}(\text{MSD})=-10\times\log_{10}\left(\frac{1}{n}{\sum_{i =1}^{n}}\frac{1}{y_{i}^{2}}\right) \tag{1}\]  
where \(n\) is the number of repetitions or observations and \(y_{i}\) is an observed data point.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Designation** & **W/B** & \begin{tabular}{c} **W** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **C** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **SF** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **USP** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **SP** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **VA** \\ **(kg/m3)** \\ \end{tabular} & \begin{tabular}{c} **PP** \\ **(kg/m3)** \\ \end{tabular} & \
\begin{tabular}{c} **LCA** \\ **(kg/m3)** \\ \end{tabular} &
\begin{tabular}{c} **FA** \\ **(kg/m3)** \\ \end{tabular} \\ \hline LC1 & 0.28 & 51.76 & 177.32 & 11.96 & 11.96 & 3.85 & 0.81 & 0.11 & 576.33 & 0.00 \\ LC2 & 0.28 & 59.24 & 220.23 & 0.00 & 0.00 & 2.20 & 0.22 & 0.03 & 569.33 & 29.96 \\ LC3 & 0.31 & 69.38 & 220.19 & 9.57 & 9.57 & 4.57 & 0.24 & 0.07 & 556.46 & 61.83 \\ LC4 & 0.28 & 60.35 & 224.36 & 0.00 & 0.00 & 2.24 & 0.22 & 0.03 & 597.48 & 0.00 \\ LC5 & 0.31 & 61.82 & 196.18 & 8.53 & 8.53 & 4.08 & 0.21 & 0.06 & 597.28 & 31.44 \\ LC6 & 0.28 & 60.25 & 206.42 & 14.07 & 14.07 & 4.48 & 0.94 & 0.13 & 592.30 & 65.81 \\ LC7 & 0.31 & 62.57 & 198.59 & 8.63 & 8.63 & 4.13 & 0.22 & 0.06 & 612.18 & 0.00 \\ LC8 & 0.28 & 61.03 & 209.08 & 14.26 & 14.26 & 4.54 & 0.95 & 0.13 & 607.56 & 31.98 \\ LC9 & 0.28 & 61.42 & 228.34 & 0.00 & 0.00 & 2.28 & 0.23 & 0.03 & 612.45 & 68.05 \\ \hline \hline \end{tabular}  
Notes: W/B, water-to-binder ratio; W, water; C, cement SF, silica frame; USP, ultra-fine silica powder; SP, superplasticizers; VA, viscous agent; PP, polypropylene fiber; LCA, lightweight coarse aggregate; FA, fine aggregate.  
\end{table}
Table 7: The mix proportions of the fiber-reinforced LPC.