## 3 Results
### Workability by Type of Foaming Agent
#### 3.1.2 Mechanical Tests from Optimum Mix Proportion  
Test specimens for compressive and flexural strength tests were fabricated using the mix proportions derived from the preceding tests. The mix design for specimen fabrication is shown in Table 4. A specimen with a 100 mm diameter and a 200 mm height was fabricated by referring to KS F 2405 (Concrete Compressive Strength Test Method) to investigate the compressive strength characteristics [21], and a 100 \(\times\) 100 \(\times\) 400 mm\({}^{3}\) specimen was manufactured in accordance with KS F 2566:2014 (Test Method for the Flexural Performance of Fiber-reinforced Concrete) to examine the flexural behavior characteristics [22]. For the test, light transparent concrete in which 5 and 10 mm plastic bars were inserted at 10 mm intervals was manufactured along with the general flexural test specimen to investigate the flexural behavior characteristics of light transparent concrete into which the bars are inserted. The reason that the diameters of the two types of plastic bar (5 and 10 mm) and the intervals between the bars were set to 10 mm is that as the number or diameter of the bars increases, as shown in Figure 6, the ratio of the bars to the total area of the specimens also increases, which in turn affects the light transmittance. On the contrary, the flexural strength of light transparent concrete is inversely proportional to the number of bars and their diameter. Thus, PVA fiber was added to address this. The mixing ratio of the fibers was determined to be 0.2%, which showed excellent consistency in the preceding test for deriving the optimum mix proportion. Figure 7 shows the production process for light transparent concrete. Figure 8 shows examples of the specimen images. The compressive strength test was conducted on the specimen subjected to 28-day curing, and the compressive strength was measured using a universal testing machine with a 1000 kN capacity. With respect to the flexural behavior characteristics, deflection-measuring devices (LVDTs) were attached to both sides of the center of the span to measure the deflection at the center of the specimen, and a data logger (UCAM) was used to measure and record the deflection (Figure 9). For the loading rate, the rate of increase in tensile stress was set at 0.06 \(\pm\) 0.04 MPa per second. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Type** & **Specimen** & \begin{tabular}{c} **WC Ratio** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **Water** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **Binder** \\ **(\%/m)** \\ \end{tabular} & \begin{tabular}{c} **Cement** \\ **(\%/m)** \\ \end{tabular} & \begin{tabular}{c} **Hy Ash** \\ **(\%/m)** \\ \end{tabular} & \begin{tabular}{c} **Lightweight** \\ **Aggregate (kg/m)** \\ \end{tabular} & \begin{tabular}{c} **Foam** \\ **(\%/m)** \\ \end{tabular} & \begin{tabular}{c} **Fiber** \\ **Contents (\%)** \\ \end{tabular} & \
\begin{tabular}{c} **Bar Space** \\ **(mm)** \\ \end{tabular} &
\begin{tabular}{c} **Bar Diameter** \\ **(mm)** \\ \end{tabular} \\ \hline \hline Fcam & F1 & 45 & 294 & 206 & 206 & - & - & 500 & - & 10 & 5,10 \\ \hline Fly ash + Foam + Lightweight Aggregate & F2 & 45 & 170 & 131 & 98 & 33 & 175 & 525 & - & 10 & 5,10 \\ \hline Fly ash + Foam + Lightweight Aggregate & F3 & 45 & 170 & 131 & 98 & 33 & 175 & 525 & 2 & 10 & 5,10 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Proportions of mix for the test of basic properties. Figure 8: Light transmittance according to the diameters and intervals between bars. Figure 6: Economical efficiency and light transmittance according to changes in the number of plastic bars. Figure 7: Production process for light transparent concrete. The results of the compressive strength test that was performed are shown in Figure 10. The compressive strength was considerably high in F1 (5.51 MPa), followed by F2 (2.39 MPa) and F3 (1.91 MPa).