本文根据国内外对钢骨混凝土结构的研究，介绍了钢骨混凝土结构的发展和特点，钢骨与混凝土的共同工作，梁、柱构件的正截面和斜截面受力性能、刚度和裂缝、抗震性能及其有关计算理论，梁柱节点的受力性能和适合我国工程应用的梁柱节点连接构造形式及试验研究，还介绍了钢骨混凝土结构在我国的工程应用情况。

Seven specimens were tested to investigate shear strength of reinforced concrete columns strengthened by wrapping carbon fiber reinforced plastic sheet. All specimens were tested under lateral reversal cyclic loading and a constant axial load. The main parameters considered were CFRP sheet amount, shear span/depth ratio and axial load ratio. Many strain gauges were attached to CFRP sheet to obtain its shear contribution. It was found that the shear behavior of RC part of the strengthened column was almost the same as that of the unstrengthened one. The parameters were found to have an influence on the shear contribution of CFRP sheet, which could be explained by truss-arch shear resistance mechanism. A simple superposition method is suggested to calculate the shear strength of the strengthened column, in which a shear coefficient (ν) is proposed to evaluate the shear contribution of CFRP sheet based on the test results. The calculated results of suggested method are shown to be in reasonable agreement with test ones.

A new type of passive controlled RC shear wall, called dual function slitted shear wall (DFW wall), was proposed by the first author. DFW wall is formed by setting connectors in the vertical slits of RC slitted wall. DFW wall can provide larger stiffness and strength than RC slitted wall under small and moderate earthquake, and performs a ductile flexure failure as RC slitted wall with the failure of connectors under severe earthquake. Experimental studies to investigate the seismic behaviors of DFW wall, including seven wall specimens and thirteen connector specimens, were introduced firstly in this paper. Then an analytical model was proposed to calculate the full skeleton load-displacement relation for DFW wall. The analysis results were found agree well with test ones. A dual seismic structure model was used to study the dynamic response of DFW wall using time history analysis method. The experimental research and analysis demonstrated the dual control functions, and showed that DFW wall has better seismic performance than the corresponding slitted shear wall.

Eight specimens, including two strengthened after loaded to yield level to imitate strengthening with some damage and one strengthened under a sustained axial load to imitate strengthening under service condition, were tested under constant axial load and lateral cyclic load to investigated seismic performance of RC columns strengthened with carbon fiber reinforced polymer sheet (CFRP sheet). The ductility increment with the confinement of CFRP sheet was studied by the strain development and distribution of CFRP sheet. Based on the experimental results, a confinement factor of CFRP and an equivalent transversal reinforcement index were suggested. Thus, the seismic design method of current Chinese seismic design code for RC column can be directly used in determining seismic strengthening amount of CFRP sheet.

Based on the visual graphical procedure of capacity spectrum method (CSM), a new method, called capacity-demand curves method (CDCM), is proposed for performance/displacement seismic design in this paper. The new method can be drawn from CSM but could avoid its disadvantages in difficult determination of demand point and larger error induced for long period system. Then the method is developed to determine the seismic performance/displacement including damage degree of structures and the corresponding probability under multiple earthquake hazard levels. All the procedures are presented in illustrative format which are easy to be understood and the values are easy to be determined. The demand curves, reflecting the relations of elastic and inelastic response, are based on the suggestion of R-μd relations in previous studies, and comparison of different models is discussed.