The authors conducted a study of aging effect on a laminated natural rubber bearing actually used in a seismically isolated building for about twenty years. No obvious change was recognized for fundamental characteristics of the rubber bearing, mechanical characteristics of inner rubber, and adhesive strength between inner rubbers and steel plates.
Also it was found that creep deformation of the rubber bearing corresponded precisely to a prediction formula.
These test results led a conclusion that natural rubber bearings would have considerable durability under long and severe environmental conditions.
