Experimental Study On Seismic Behavior Of Cold-formed Steel Reinforced High-strength Concrete Medium-high Wall With Different Types Of Concealed Bracings

With the continuous increase in the height of buildings, the utilization ofhigh-strength concrete has become a trend. Although the structure of steel reinforcedhigh-strength concrete has overcome the disadvantages of high-strength concrete, suchas poor ductility and sudden failure, it’s hard to avoid the problem of larger amount ofsteel and higher cost. Compared with ordinary hot-rolled steel, cold-formed steel hascharacteristics of light weight, high strength, small weight and good seismicperformance. Thus, if the ductility of structures can be ensured by using thecold-formed steel instead of common steel as the concealed bracings of High-strengthConcrete Medium-high Wall, the project cost can be reduced.The author did tests of four cold-formed steel reinforced high-strength concreteshear walls (SRHCW)，with a shear-span ratio of1.8， which had the same edge steeland cold-formed steel，and different types or different steel ratio of concealed bracings.Then the seismic behavior of SRHCW, which had the different steel ratio and differenttypes of concealed bracings, was discussed. On basis of these trials，the main work andachievements of this paper are as follows:①Level cyclic loading experiments were conducted on the cold-formed steelreinforced high-strength concrete (SRHC) shear walls with different layouts ofconcealed bracings under the axial compression ratio of0.24，and the failure modes andfailure mechanism of the cold-formed steel reinforced high-strength concrete(SRHC)shear walls with different layouts of the concealed bracings were obtained.②Since trussed construction was characterized by a clear way of forcetransmission and stress performance, the test riveted their concealed cold-formedsteel bracing with the embedded column type steel in order to form an inner steeltruss. The seismic performance of the shear wall with inner steel truss structure wasanalyzed and concluded, which paved the way for future architectural design.③Comparatively analyzed on the hysteretic curves，skeleton curves，ductility，energy dissipation and rules of strength degeneration.④Discussed on the percentage of shear deformation and bending deformation ofthe total.⑤Comparatively analyzed on the cold-formed stress distribution of cold-formedsteel. ⑥This paper established the mechanical models of elastic stiffness, by comparingthe calculated values with the experimental results, thus made a preliminary study onthe elastic stiffness of cold-formed steel reinforced high-strength concrete shear walls.⑦This paper established the mechanical models of bearing capacity，comparatively analyzed the calculated values with the experimental results and obtainedthe computational formula of flexural bearing capacity of shear wall, thus made apreliminary study of deformation capacity of cold-formed steel reinforced high-strengthconcrete shear walls.The experimental results show that，the seismic capacity of cold-formed steelreinforced high-strength concrete (SRHC) wall with concealed bracing is superior togeneral SRHC shear wall. Therefore, the types of concealed bracings given by thispaper provide a reference to engineering design.