The moment capacity and rotational stiffness of wedge joints, which connect vertical and horizontal members of assembled support systems, were evaluated experimentally considering the characteristics of reused members. Since temporary structures, such as supports, tend to be reused, experiments were conducted with reused members, and the normality of the measured data was assessed. The lower and upper limits of the 95% confidence intervals of the moment capacity and rotational stiffness of wedge joints with reused members were determined. Experiments were also conducted on a joint system with new members to analyze the influence of reused members. In integrating both new and reused members, the maximum moments of wedge joints were observed to be normally distributed. The lower limit of the 95% confidence interval of the maximum moment of joints was 0.997 kNm, and the upper limit was 1.074 kNm. The rotational stiffness of the wedge joint was evaluated using a trilinear model. The initial rotational stiffness decreased with continued use of the joint. The average rotational stiffness of the joint, analyzed by combining the results for new and reused members, was found to be 22.475 kNm/rad for the first interval, 4.705 kNm/rad for the second interval, and 1.577 kNm/rad for the third interval. The lower limit of the 95% confidence interval of the initial rotational stiffness was 20.688 kNm/rad, and the upper limit was 24.262 kNm/rad.

The deployment of ultra-high-performance concrete (UHPC) is a strategic response to the urgent need for advanced building materials, particularly for the repair and enhancement of aging infrastructure. Highway bridges, which are constantly subjected to high stress, heavy usage, and corrosive environments, can be ideal candidates for UHPC application. The material’s exceptional abrasion resistance and ability to withstand severe weather conditions make it a compelling choice for projects where frequent renovation or maintenance is impractical. This study presents a risk-based cost–benefit analysis (RCBA) comparing UHPC reinforced bridge columns to conventional concrete reinforced bridge columns, focusing on seismic and corrosion hazards. While UHPC has a significantly higher initial material cost than traditional concrete, a simple comparison of initial costs alone is misleading. The RCBA methodology generally evaluates life-cycle cost, including initial construction, long-term agency costs, and user costs. The central question—whether UHPC’s superior performance justifies its higher initial investment—is addressed through RCBA. The presented RCBA is formulated as the ratio of the total life-cycle cost of conventional concrete to that of UHPC. The benefit is estimated as the difference in cumulative risks between bridges with conventional concrete and UHPC bridge columns, with fragility analysis conducted under seismic and corrosion hazards. The proposed approach is illustrated using an existing bridge located in Republic of Korea.