## 2 Experimental Program  
### Material Properties  
Figure 5 shows an overview of the materials selected in this study. As shown in the Figure, a screw iron (SI) rod was employed as a new reinforcing material. Perforated bricks with three holes, produced in Japan, were employed in this study since the local products of the region of South East Asia were not available. It was noted that the main purpose of this study was the application of SI rods to perforated bricks and the investigation of the internal reinforcing effects on structural performance; therefore, the perforated bricks from Japan were adopted at this time. The mortar mix proportion of sand, cement, and water was 11:1:1 (weight ratio). In addition, in order to solve the problem of the integrity and bonding behaviors between the steel bars and mortar, which were raised in the previous study by the author [49], the use of deformed reinforcing bars with screws (threaded reinforcing bars) was first considered. By fixing the bricks at both ends using screw reinforcing bars and nuts, it was thought that the integrity of the members as well as the bonding between the reinforcing bars and mortar could be assured. On the other hand, SI rods, which were  
Figure 4: Brick masonry damage from Central Java Earthquake (2006).  
easily available compared to screw reinforcing bars, were selected as a new reinforcing material. Hence, M14 with a nominal cross-sectional area of 115 mm\({}^{2}\) was used for the SI rods, and the steel plate was attached to both ends of the brick member in some specimens, as explained later. It was noted that the thickness of the steel plate (9 mm) was selected after examining the bearing pressure of the nut and the safety against the punching shear.  
Tables 1-3 show the material test results, and the values are the mean values of 3 samples in each test. For the material tests, a compression test of the brick unit and the 3-layer stacked prism, a push-out test of the 3-layer stacked prism, mortar compression and splitting tests, and a tensile test of the SI rod were carried out. Herein, two types of 3-layer stacked prisms were fabricated, which were the cases with or without the SI rods. A total of three SI rods were inserted into each hole. The compressive strength of the 3-layer stacked prism was 21.1 MPa in the case without SI rods and 23.0 MPa in the case with SI rods. From this result, the effect of the reinforcing rod on the compressive strength was regarded to be slight. On the other hand, from the push-out test, the shear strength was found to be 0.7 MPa when the stacked prism had no SI rods, and the shear strength with SI rods was calculated to be 3.2 MPa. Through these material test results, it was confirmed that the iron rods did not contribute much to the increase in compressive strength but had great effects on the shear strength. The 0.2% offset method was used to determine the yield point of the SI rod because there was no clear yield point from the tensile test.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Brick Unit** & **Mortar** \\ \hline Compressive strength & 39.1 MPa & 15.1 MPa \\ \hline Tensile strength \(\sigma_{T}\) & — & 0.9 MPa \\ \hline \hline \end{tabular}
\end{table}
Table 1: Material characteristics of brick unit and mortar.  
Figure 5: Selected material in this study: (**a**) Perforated brick (mm); (**b**) Screw iron rod (M14); (**c**) Steel end plate; (**d**) Nut; (**e**) Washer.