## 3 Results and Discussion  
### Crack Pattern and Failure Mode  
Figure 6 shows the crack patterns and failure modes of the four tested walls. The drift ratio was computed as the horizontal displacement divided by the actual height of the wall (2790 mm). PCMW was a rectangular wall with a prefabricated construction technique. Several stepped mortar joint cracks were observed at both segments at the load of 420 kN with a 0.09% drift loading cycle. No cracks were seen at the vertical joint. The first major diagonal crack was visible at 6 mm with a 0.21% drift loading cycle and extended to the right toe of the wall. A few stepped mortar joint cracks were seen over the lower five courses above the foundation at a distance about 600 mm from both wall ends. During the loading cycle at 12 mm with a 0.43% drift cycle, the wall reached its lateral capacity of +624 kN and \(-\)675 kN for both directions. As the test continued, progressive penetration of the diagonal cracks extended to the full height of the wall at 18 mm with a 0.64% drift loading cycle. The cracks were distributed on the entire wall. The major diagonal crack became wider and the mortar at the interaction of the bed and head joints expanded outwards, which led to a separation between mortar and units at 24 mm with a 0.86% drift loading cycle. The wall lost 8% of its lateral strength. During the loading cycle at 30 mm with a 1.07% drift top wall displacement, face shell spalling of units along the major diagonal crack occurred. Vertical cracks at the wall tees over the lower three courses above the foundation reinforced concrete beam widened and resulted in a face shell separation. Furthermore, damage in both sides of the segments was more severe than in the vertical joint with respect to the width and quantity of the diagonal cracks. The test ended with the strength decreasing to 74% of peak load. PCMWT was a flanged wall with a prefabricated construction technique. A similar crack pattern was observed in both PCMWT and PCMW. PCMWT showed elastic behavior until the loading reached 660 kN. The first slight cracks were observed in the positive loading direction at a lateral load of +720 kN and a top lateral load of 3.64 mm with a 0.13% drift. The first visible cracks were composed of a combination of several stepped cracks along the mortar bed joints and head joints as well as diagonal cracks penetrating through the masonry units at the lower half of the wall. As the imposed lateral displacement increased, the first major diagonal crack appeared and simultaneously extended to the full height of the wall at the 4 mm with a 0.14% drift loading cycle. With further loading, the wall reached its lateral capacity of 906 kN for the positive direction at 8 mm with a 0.29% drift loading cycle. During this loading circle, horizontal mortar cracks were observed at webs of the flanges up to the fifth course. The wall reached an ultimate resistance of \(-\)857 kN for the negative direction at 12 mm with a 0.43% drift loading cycle. Diagonal cracks parallel to the major ones in both directions were observed and constantly extended  
Figure 5: Loading procedure. to the ends of the walls at approximately 45 degrees. Vertical cracks in both flanged end zones extending to the fourth course were also seen. During the loading cycle at 20 mm with a 0.71% drift top wall displacement, extensive diagonal cracks extended into wall toes and distributed on the entire wall. The crack width continued to increase. The wall lost about 18% of its capacity. The major diagonal crack gradually became distinct with a width of 6 mm at 24 mm with a 0.86% drift loading circle. Spalling of the face shells along the major diagonal crack at both segments occurred as the crack continued to widen. At the end of the test and at 32 mm with 1.14% drift loading cycle, vertical cracks at the flanged end zone and the major diagonal crack became wider. A significant face shell spalling in these regions led to a loss of 38% of the wall capacity. CMW was a rectangular wall with a traditional construction technique.