## 3 Results and Discussion
### Bearing Capacity  
Figure 8 shows the cracking load, yield force, and peak force during loading. When the first horizontal crack appeared in the tensile zone of the specimen, the corresponding horizontal force was called the cracking load. The corresponding horizontal force was the yield load, when the outermost rebar of the specimen yielded. The peak load was the maximum horizontal force that the specimen could resist. It can be seen from Figure 8 that the cracking load of the prefabricated walls were higher than that of the cast-in-place wall, which was mainly because the existence of the sleeve and the grouting material restricted the longitudinal deformation of the concrete. The negative cracking load of specimen LAPC-2 was lower than that of the other two specimens due to the thin concrete cover of the L-shaped-edge member and the influence of loading eccentricity. Figure 8: Comparison of hysteresis curves and skeleton curves of specimens: (**a**) hysteresis curve of LSW; (**b**) hysteresis curve of LAPC-1; (**c**) hysteresis curve of LAPC-2; and (**d**) skeleton curves of the three specimens. The positive yield load of each specimen was less than the negative yield load, and the peak load was not reached during positive loading. This was due to the fact that the L-shaped-edge member had a larger concrete cross-section and more rebars, leading to a higher bearing capacity. For prefabricated components, the existence of the sleeve and the grouting material improved the bearing capacity of the compression area at the bottom of the wall. Due to the large cross-sectional area of the type-II APC sleeve and grouting material in specimen LAPC-2, the concrete in the compression zone was more constrained, so the yield load was higher than that of specimen LAPC-1. Furthermore, due to the longer length of the type-II APC sleeve, the weak section (the top surface of the sleeve) moved up more during failure, so the peak load was higher than that of the other two specimens. Since the stirrups and the horizontally distributed rebars at the bottom of each wall were densified, the densification of the rebars could improve the bearing capacity of the cast-in-place wall and prefabricated walls. However, owing to the effect of the sleeves, the densified rebars had little effect on the bearing capacity of the prefabricated specimens, which caused the yield load and the peak load of specimen LSW and specimen LAPC-1 to be similar. According to the Chinese standard [30], the peak load of the cast-in-place specimen can be calculated as follows:  
\[ \begin{array}{l}N\leq A_{s}^{\prime}f_{y}^{\prime}-A_{s}\sigma_{s}-N_{sw}+ \alpha_{1}f_{c}b_{w}x\\ M\leq A_{s}^{\prime}f_{y}^{\prime}(h_{w0}-a_{s}^{\prime})-M_{sw}+\alpha_{1}f_ {c}b_{w}x(h_{w0}-\frac{x}{2})-N(h_{w0}-\frac{h_{w}}{2})\\ if\ x\leq\xi_{b}h_{w0}\\ \sigma_{s}=f_{y}\\ N_{sw}=(h_{w0}-1.5x)b_{w}f_{sw}\rho_{w}\\ M_{sw}=\frac{1}{2}(h_{w0}-1.5x)^{2}b_{w}f_{sw}\rho_{w}\end{array}  \tag{2}\]  
where \(N\) and \(M\) are axial force and bending moment of cross-section, respectively. \(f_{y}\) and \(f_{y}^{\prime}\) are the tensile strength and compressive strength of reinforcement, respectively. \(A_{s}\) and \(A_{s}^{\prime}\) are the sectional areas of longitudinal reinforcement in tension and compression zones, respectively. \(a_{s}^{\prime}\) is the distance from the resultant force of the compressive reinforcement to the edge of the section. \(b_{w}\) is the thickness of the wall, and \(h_{w0}\) is the effective depth of the section. \(f_{yw}\) and \(\rho_{w}\) are the design value of strength and reinforcement ratio of vertically distributed reinforcements in the wall, respectively. \(\xi_{b}\) is the critical relative compression depth, and \(\xi_{b}=0.518\). \(x\) is the height of the compression zone of concrete. \(\alpha_{1}\) is the coefficient of the rectangular stress diagram, which can be taken as 1 if the concrete strength grade is less than C50.