We investigated the change in horizontal performance over 30 years in a seismically isolated building using natural rubber bearings, rubber bearings extracted from the building, and monitoring specimens, and found the following.
1. The horizontal load-deformation relationship and its aging change of the rubber bearings extracted from the building and the monitoring specimens matched well, regardless of whether or not they were loaded.
2. The change in stiffness of monitoring specimens over time was greater than the heat aging characteristics.
3. It is important to control the accelerated temperature in heat aging tests.
