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To quantify the post-earthquake residual seismic capacity of reinforced concrete (RC) column members, experimental data for 6 column specimens with flexural, flexural-shear and shear failure modes are used to derive residual seismic capacity of damaged RC column members for specified damage states in this work. Besides of the experiment data, some related researches are also investigated to suggest the reduction factors of strength, stiffness and energy dissipation capacity for damaged RC column members, respectively. According to the damage states of RC columns, their corresponding seismic reduction factors are suggested herein. Taking an RC column with the flexural-shear failure for an example, its reductions factors of strength, stiffness and energy dissipation capacity are 0.5, 0.6 and 0.1, respectively. This work also proposes the seismic performance assessment method for the residual seismic performance of earthquake-damaged RC buildings. In the case study, this work selects one actual earthquake-damaged school building to demonstrate the post-earthquake assessment of seismic performance for a damaged RC building.

The main propose of this work is to investigate the shear crack development and suggest the design formulas that can ensure serviceability and reparability for shear-critical high-strength reinforced concrete (HSRC) beam members based on the experimental data of ten full-size simple-supported beam specimens. According to the experimental results, the design formulas that can ensure the serviceability and reparability are recommended for shear-critical HSRC beam members. Additionally, relationship between shear stresses of member and widths of shear cracks are also built for the quantitative analysis of shear crack development. Based on the crack development of each specimen, the average ratio of the residual total shear crack widths to the residual maximum shear crack width for the HSRC beam specimens is approximately 4.5; then, in the crack-based assessment, this work recommends setting the ratio as 4.0 to estimate residual maximum shear cracking. Additionally, the ratio of maximum peak shear crack width to residual maximum crack width, it can be increased by shortening stirrup spacing and increasing stirrup strength, and its overall average value is 2.44. This work suggests the applicable value of a HSRC shear-critical beam to be 2.5. Besides of the post-earthquake damage assessment, these results can also be used to build the performance-based design for HSRC structures.

To quantify the post-earthquake residual seismic capacity of reinforced concrete (RC) column members, experimental data for 6 column specimens with flexural, flexural–shear and shear failure modes are used to derive residual seismic capacity of damaged RC column members for specified damage states in this work. Besides of the experiment data, some related researches are also investigated to suggest the reduction factors of strength, stiffness and energy dissipation capacity for damaged RC column members, respectively. According to the damage states of RC columns, their corresponding seismic reduction factors are suggested herein. Taking an RC column with the flexural–shear failure for an example, its reductions factors of strength, stiffness and energy dissipation capacity are 0.5, 0.6 and 0.1, respectively. This work also proposes the seismic performance assessment method for the residual seismic performance of earthquake-damaged RC buildings. In the case study, this work selects one actual earthquake-damaged school building to demonstrate the post-earthquake assessment of seismic performance for a damaged RC building.

This study tests ten full-size simple-supported beam specimens with the high-strength reinforcing steel bars (SD685 and SD785) using the four-point loading. The measured compressive strength of the concrete is in the range of 70-100 MPa. The main variable considered in the study is the shear-span to depth ratio. Based on the experimental data that include maximum shear crack width, residual shear crack width, angle of the main crack and shear drift ratio, a simplified equation are proposed to predict the shear deformation of the high-strength reinforced concrete (HSRC) beam member. Besides the post-earthquake damage assessment, these results can also be used to build the performance-based design for HSRC structures. And using the allowable shear stress at the peak maximum shear crack width of 0.4 and 1.0 mm to suggest the design formulas that can ensure serviceability (long-term loading) and reparability (short-term loading) for shear-critical HSRC beam members.

The design of headed bars in interior and exterior beam-column joints to ensure satisfactory seismic anchorage performance has recently become a very important issue. This work investigates the seismic anchorage behavior of headed bars using 12 groups of fullsize specimens of exterior and interior beam-column joints and suggests design requirements for headed bars in such joints. On the basis of the experimental investigation, this work comprehended the seismic anchorage behavior of headed bars using full-size specimens of exterior and interior beam-column joints and suggested design requirements for headed bars in such joints. Additionally, the application of headed bars with spliced and butted types on interior beam-column joints is also proved in this work. Therefore, based on the experimental results, the minimal required net spacing of headed bars can be set at 2.2d b , instead of 4.0d b , for seismic designs, and the minimal required anchorage length in ACI 318-11 for non-seismic design members can be used in seismic members.

In the estimation of the losses caused by an earthquake for a reinforced concrete (RC) building, the effect of corrosion of the reinforcing steel incurred by environmental conditions, e.g. carbonation and chloride ions, is seldom mentioned because of the corrosion with uncertainty and time dependence. However, because the structural capacity of a corroded RC building declines over time, one must apply an appropriate method that estimates the structural capacity of an RC building in a corrosive environment. Therefore, this work integrated degradation factors into the structural properties of a corroded RC building. Additionally, by considering life-cycle earthquake events, lifetime losses resulting from earthquakes and corrosion can be derived. This work can help both owners and investors to identify lifetime losses of RC buildings due to seismic structural damage, including the corrosion effect, within a specified service life. Although the case study only addresses a selection of the most appropriate concrete cover depth for an RC building corroded by chloride ions, the proposed procedure can be utilised when making decisions about whether to prevent building deterioration based on economic considerations.

The purpose of this study is to investigate the flexural crack development of high-strength reinforced concrete (HSRC) beams and suggest the design equations of the flexural crack control for HSRC beams. This study conducts two full-size simplysupported beam specimens and seven full-size cantilever beam specimens, and collects the experimental data of twenty full-size simply-supported beams from the past researches. In addition to high-strength reinforced steel bars of specified yielding stresses of 685 and 785 MPa, these specimens are all designed with the high-strength concrete of a specified compressive stress of 70 or 100 MPa. The experimental data is used to verify the application of the flexural crack control equations recommended in ACI 318-14, as reported by AIJ 2010, as reported by JSCE 2007 and as reported by CEB-fib Model Code 2010 on HSRC beam members; then, this study concludes the design equations for the flexural crack control based on ACI 318-14. Additionally, according to the experimental data, to ensure the reparability of an HSRC beam member in a medium-magnitude earthquake, the allowable tensile stress of the main bars can be set at the specified yielding stress of 685 MPa.