## 4 Results
### Probabilistic Value of Moment Resistant Capacity  
To evaluate the resistance moment capacity of the joint, the relationship between the moment, which was calculated by multiplying the distance from the loading point to the joint (500 mm as shown in Figure 2) by the load value, and the displacement measured by each LVDT was analyzed, as shown in Figures 9-12. The maximum moment in each specimen is summarized in Table 4.  
From Figures 9 and 10, which show the time history relationship between the resistance moment at the joint and the displacements measured by LVDT1 and LVDT2 installed on the horizontal members, it was found that the resistance moments of specimens with new members were higher than those of specimens with reused members. As the reuse period increased, the magnitude of the displacement increased for a given moment, and the deviation of the moment-displacement curves of the specimens also increased. Moreover, for longer reuse periods, some specimens yielded at relatively low moment values. However, it must be noted that the displacements shown in the figures for the new specimens are small because the capacity of the LVDTs used for displacement measurement was 50 mm, and thus displacements larger than 50 mm could not be measured. LVDTs with a capacity of 100 mm were used for measurement of the displacements of the reused specimens. For new specimens, the maximum displacement will be higher than the measured data. However, it is anticipated that the difference will be small by viewing the trend of moment-displacement curves of specimens with a one-year reuse period. In the specimens with a seven-year reuse period and some specimens with a four-year reuse period, the additional increase of moment was occurred after the yielding. This phenomenon derived from the contact between the joint ring and grove surface. As explained in the failure mode (Figure 6), little space in the grove at the end of horizontal members, where the joint ring was passed, developed the additional resistance in the joint system after yielding the system. Figures 11 and 12, which illustrate the time history relationships between the resistance moment at the joint and the displacements measured by LVDT3 and LVDT4, installed on the vertical member, show that the vertical member exhibited linear behavior until the specimens reached failure and that the slope decreased as the reuse period increased. Moreover, as the reuse period increased, the displacement increased for a given moment, and the deviation of the moment-displacement curves of the specimens also increased. In other words, it appears that an increase in the reuse period decreases the moment capacity and increases the quality deviation. In particular, as the deviation increase of the specimens leads to an increase in the member failure probability, it appears that uneven performance of the joint due to an increase in the reuse period can be a potential cause of the collapse of a support system. Table 4 shows the maximum moment of each specimen. The maximum moment of the specimens with new members ranged from 0.88 to 1.26 kNm, with an average value of 1.13 kNm (standard deviation: 0.11 kNm, coefficient of variance: 0.097). For the specimens with a one-year reuse period, the maximum moment of the joint ranged from 0.86 to 1.08 kNm, with an average of 0.97 kNm and a standard deviation of 0.07 kNm (coefficient of variance: 0.068). The average maximum moment was 0.98 kNm (standard deviation: 0.08 kNm, coefficient of variance: 0.077) for the specimens with a four-year reuse period and 1.07 kNm (standard deviation: 0.17 kNm, coefficient of variance: 0.160) for the specimens with a seven-year reuse period. The average maximum moment of the specimens with new members was the highest. It was 1.16 times higher than that of the specimens with a one-year reuse period, 1.15 times higher than that of the specimens with a four-year reuse period, and 1.06 times higher than that of the specimens with a seven-year reuse period.