**3. Test Results**

#### *3.1. Failure Phenomenon and Pattern*

The failure patterns of the five specimens are presented in Figure 8. All the specimens experienced three phases, such as cracking, peak, and failure in the experiment, but the failure process of the specimens W1, W2, and W3 were different from the specimens W4 and W5. Without structural columns, the specimens W1, W2, and W3 (bare walls) reached the ultimate strength and were destroyed immediately after the walls cracked, indicating the specimens had poor ductility and bearing capacity. On the contrary, the specimens W4 and W5 (reinforced walls) reflected better ductility and bearing capacity due to the constraints of the structural columns and ring beams. The analysis of the failure patterns of all the specimens is as follows:

1. In the initial stage of loading, horizontal cracks occurred on both sides of the wall root of the specimen W1 due to the flexural effect. By this time, no obvious cracks occurred in the diagonal

direction because the shear strength of the diagonal direction did not reach the cracked load. As the horizontal load increased, the horizontal cracks propagated rapidly and linked together gradually at the wall root, and the visible flexural e ffect was more apparent under horizontal loading. When the horizontal load reached the ultimate load, the mortar joint between the infill wall and the bottom beam was destroyed completely. Meanwhile, the specimen hardly bore the lateral load, indicating that specimen W1 failed. Therefore, the failure process of W1 was predominantly a ffected by the flexural e ffect;


#### *3.2. Characteristic Load and Displacement*

As can be noticed in Table 4, the ultimate load and the cracking load of the specimens W1 was 98% and 185% lower than that of W2, respectively, which showed that increasing the vertical load could increase the bearing capacity of specimens. The cracking load and the ultimate load of the specimen W2 was higher compared to W3, which indicated that the bearing capacity of specimens was decreased with the increasing aspect ratio.

(**a**) W1 (**b**) W2 

**Figure 8.** *Cont.*


**Figure 8.** Failure mode of specimens: (**a**) W1; (**b**) W2; (**c**) W3; (**d**) W4; (**e**) W5.


**Table 4.** Characteristic load and displacement.

Key: *Pcr* is the cracking point; Δ*cr* is the cracking displacement; *Pu* is the peak load; Δ*u* is the peak displacement.

The ultimate load and the cracking load of W4 and W5 exhibited about a 127%, 127%, 72%, and 114% increase compared with W1, respectively, indicating that the constraint imposed by the structural columns could significantly improve the bearing capacity of the walls. Besides that, the cracking load and ultimate load of the W5 were slightly lower than that of the W4, reflecting the bearing capacity of the ordinary concrete structural column was higher than that of the RAC structural column.

## **4. Test Analysis**
