**5. Conclusions**

The following conclusions can be drawn from the low cyclic experiments on steel frames with infilled cast-in-place RACSWs and prefabricated RACSWs:

(1) The bearing capacity and initial sti ffness were 2.4 and 4.3 times higher in the steel frames with infilled cast-in-place RACSWs than those in the pure steel frame. The displacement ductility factors were from 2.44 to 2.69. The degradation coe fficients of the bearing capacity remained over 0.80 when the horizontal drift angle was 0.02 rad, thereby indicating that the specimens of infilled cast-in-place RACSWs had a high safety reserve.

(2) Compared with the cracking load of the specimen of infilled RACSWs with a 100% replacement rate of recycled coarse aggregate, that of the infilled ordinary concrete wall increased by 37%, the yield load decreased by 22%, and the bearing capacity was nearly the same. These results indicate that the performance of RACSWs was nearly the same as that of an ordinary concrete wall in the structure of steel frames with infilled shear walls.

(3) The yield and peak loads of the specimen decreased by only 13% and 8%, respectively, in the end-plate joints compared with those in the welded–bolted joints. Furthermore, the initial sti ffness was reduced by approximately 13%. The infilled cast-in-place RACSWs relieved the rotation deformation of semi-rigid joints and weakened the influence of the connecting sti ffness of BCJs on the bearing capacity of the structure of infilled cast-in-place RACSWs.

(4) The bearing capacity and initial sti ffness were 1.44 and 2.8 times higher in the steel frames with infilled prefabricated RACSWs than those in the pure steel frame, and the displacement ductility factors were from 3.32 to 3.40. The di fference in bearing capacity of the specimens in the welded–bolted and end-plate joints was only 4%, and the turning capability and ductility were better in the semi-rigid joints than in the rigid joints.

(5) The connectors between the steel frames and prefabricated RACSWs were undamaged during the test, and the shear force was transferred successfully. The cracks in the horizontal direction were formed at the connection between the embedded T-shape connectors and the walls, and shear failure occurred in the specimens. Therefore, the connection construction between the embedded T-shape connectors and walls should be given su fficient attention.

(6) The prefabricated shear walls made of recycled coarse aggregate improved the lateral sti ffness and bearing capacity of the structure of infilled prefabricated RACSWs. The structure of infilled prefabricated RACSWs was characterized by a favorable deformation capability to satisfy the design requirements of structure behavior in the seismic fortification area. The walls and steel frames could be rapidly installed in the construction field. Furthermore, the structure of the infilled prefabricated RACSWs was safe, highly e fficient, convenient to repair and replace after an earthquake, and had a satisfactory engineering application value.

**Author Contributions:** Conceptualization, L.S. and H.G.; methodology, Y.L.; software, Y.L.; validation, L.S., H.G.; and Y.L.; formal analysis, L.S.; investigation, L.S.and H.G.; resources, H.G.; data curation, L.S.; writing—original draft preparation, L.S.; writing—review and editing, L.S. and H.G.; visualization, L.S.; supervision, Y.L.; project administration, H.G.; funding acquisition, H.G. and Y.L.

**Funding:** This research was funded by the National Natural Science Foundation of China No. 51308454. **Conflicts of Interest:** The authors declare no conflicts of interest.
