## 6 Conclusions  
The following observations and conclusions can be drawn from the studies reported in this paper:  
(1) This study adopted a new anchored blind-bolted moment connection to CFST columns, and the anchored blind bolts and a locally strengthened steel tubes were applied to effectively avoid the premature anchorage failure and CFST column damage. The anchored parts of the blind bolts in the concrete were not damaged, providing continuous and reliable effect on the performance of the connections throughout their entire cyclic loading. The steel tube wall and the C-channel can work well together when plug weld was adopted between them. The test observations the proposed joints can be fully utilize the bolt strength and significantly improves the joint performance, especially in terms of strength and strength degradation. (2) Three typical failure modes were found in the experiment for the anchored blind-bolted extended end-plate joints, and the failure mode depended on the weakest component. When the steel tube was not locally strengthened by the C-channel, specimens failed in mode I. These specimens showed obvious strength degradation, but exhibited better rotational capacity, ductility, and energy dissipation capacity. However, those were realized by the crushing of concrete in the columns and the deformation of the steel tube walls. When the steel tube was locally strengthened by the C-channel, specimens failed in mode II and III. Specimens that failed in mode II exhibited higher stiffness and strength. The use of the thick end-plate resulted in premature brittle fracture of the bolt. Specimens that failed in mode III were typical strong column-weak beam joints, and exhibited the highest energy dissipation capacity, which satisfied the seismic requirement for intermediate moment frames. (3) For such joints, the local reinforcement of C-channel and change in the anchorage method had a limited effect on the initial stiffness. Greater end-plate thickness and the use of stiffeners significantly increased the joint stiffness and decreased the rate of stiffness degradation. The use of stiffeners also significantly enhanced the ductility and energy dissipation by moving plastic hinge outward from the joints. (4) The anchored blind-bolted extended end-plates joints to CFST columns can meet the requirements for rotational capacity in both Eurocode-8 and FEMA-350 standards. This type of joint exhibits good rotational capacity and ductility, meeting the seismic design requirements for  
Figure 28: Stress distribution in the concrete. (**a**) Elastic stage; (**b**)Yield stage; (**c**) Ultimate stage; (**d**) Details. structures. According to EC3 Part 1-8, the anchored blind-bolted extended end-plate joints to CFST columns with a strong beam are classified as semirigid and partial-strength joints, whereas those with a weak beam are in the range of semirigid and full-strength joints. (5) The FEA models using ABAQUS/Standard was used to cross-validate the test results. The FEA models could simulate the joint behaviors with a proper accuracy, which demonstrated the reliability of the experimental results and improve the understanding of the connections. The stress distribution and force transfer pattern were investigated. Conceptualization: Y.W. ; methodology, Y.W. ; validation, P.W. and Z.W. ; formal analysis, J.P.; investigation, Y.W. ; resources, P.W. ; data curation, Y.W. ; writing--original draft preparation, Y.W. ; writing--review and editing, Y.W. and P.W. ; visualization, S.C. and J.Q. ; supervision, Z.W. ; project administration, Z.W. ; funding acquisition, Z.W and J.P. All authors have read and agreed to the published version of the manuscript. This study was supported by National Natural Science Foundation of China (Grant No. 51778241; 51638009; 51978279), the Fundamental Research Funds for the Central Universities (Grant No. 2019 MS121; 2019 PY20; 2019 ZD47), Chinese Postdoctoral Foundation of China (Grant No.