ABSTRACT
In Japan, where earthquakes occur frequently, rubber bearings are used in many road bridges because of their effectiveness in improving the seismic resistance of bridges. NEXCO (Nippon Expressway Company) has adopted the use of rubber bearings as a standard. The rubber bearings have a 10 mm cover rubber on the side surface to protect them from the environment (ultraviolet rays, ozone, etc.). But cracking due to ozone deterioration have been reported in the cover rubber manufactured according to standards prior to 2000. In recent years, ozone cracking has been observed not only in cold regions in Japan, but also throughout the country. Repair methods for ozone cracks include covering the surface of rubber bearings with tape or paint-based repair materials. However, such repair methods have problems, such as floating or peeling of the repair material. In this paper, the applicability of a new and effective repair method, in which vulcanization (reconstruction) of the cover rubber performed in the field, is examined.
