A study of aging effects on natural rubber bearing that was installed in a seismically isolated building about 30 years ago was conducted. The dynamic properties of natural rubber bearing, physical properties and chemical properties of rubber were examined and there were no significant changes compared with original properties. The creep deformation of the natural rubber bearing was also measured. It was confirmed that creep deformation corresponded precisely to the prediction formula. It was assumed that aging doesn’t lead to any significant change of the rubber bearing characteristics.
