In this paper, a prestressed precast reinforced concrete (PC) beam–column connection incorporating posttensioned debonded partial tendons is introduced for PC frame structure. Compared with the conventional cast-in-place frames and many previously proposed connections for PC frames, this connection has the advantage of self-centering and low damage in strong earthquakes. In addition, the debonded partial tendons can reduce the posttensioning demand and further reduce site labor during construction and repair. In order to establish a performance evaluation method for the ultimate flexural limit of the proposed PC connection, an analytical model was developed to accurately reflect the deformation compatibility and force equilibrium conditions of the PC beam and column members, as well as the debonded partial tendons. Based on this, iterative and direct evaluation methods for the strength and deformation of the PC connections, as well as the strains of the debonded tendons, were developed. The proposed methods were verified by cyclic loading test on the beam–column connection subassemblages. It is concluded that the proposed method is sufficiently accurate and simple to be applied in engineering design, and is helpful to guarantee the self-centering and low-damage characteristics of the proposed connection against a strong earthquake.

In order to reduce the self-weight of RC buildings and increase cost-savings, the seismic performance of rectangular hollow sectioned columns was investigated by experimental and analytical studies. Cyclic loading tests were carried out under compression axial force ratios from 0.16 to 0.3, and hysteresis curves, failure patterns, strain distributions of reinforcement, flexural and shear deformations, and energy absorption capacity were discussed in detail. Based on the experiments, under an axial force ratio of 0.16, the structural performances between hollow and solid sectioned columns were found to be almost equivalent. When the axial force ratio increased to 0.3, the structural performance was almost the same until the 2.0% drift angle; however, sudden deterioration of the load-bearing capacity occurred, with concrete compressive failure at the plastic hinge region near the column end. By means of numerical investigations by cross-sectional and FEM analysis, it was found that such brittle failure was induced by the neutral axis location and the concrete stress concentration on the hollow cross-section. Therefore, the appropriate separation of the hollow section from the plastic hinge region is recommended when the neutral axis is located beyond the flange at the ultimate flexural state.

This study focused on perforated bricks, and the structural performance enhancement of brick members by internal reinforcement was experimentally investigated. As a new reinforcing material, screw iron (SI) rods were selected for the internal reinforcement, and they were inserted into the perforated brick. To investigate the most-effective reinforcing method as well as to understand the fundamental structural behaviors, four specimens with different variables were fabricated, and three-point bending tests were carried out. From the experiments, it was found that the maximum strength of the specimen increased by more than two times with internal reinforcement. The internal reinforcement, fixed by nuts at both ends of the specimen to enhance integrity, increased the maximum strength by nine times. Moreover, the deformation capacities of the specimens were also greatly enhanced. The case where the internal SI rods were fixed by nuts without mortar also showed a similar structural performance to the case with mortar. The estimation methods of the maximum strength of the specimens were also discussed, and they showed reasonable agreement with the test results. It was proved that the proposed material and methods enabled effective utilization of the internal reinforcement, and they could contribute to the improvement of structural performances in masonry construction.