Retest of Neoprene seismic isolation bearings after 30 years

This paper describes the retest of a set of Neoprene (Polychloroprene) steel reinforced elastomeric isolator bearings that were originally tested as part of an experimental program in 1981. The original bearings were tested on a shake table as a demonstration of the feasibility of base isolation for the seismic protection of buildings. Two types of bearings were provided, and not all were used. The unused bearings were stored unloaded at room temperature for over 30years. Although there has been a very substantial improvement in the number and quality of the instrumentation available to the test program over the span of 30years, it is possible to compare the results of relatively similar shake table tests on the bearings. The shake table tests are used to assess the changes in the horizontal stiffness and damping values for the bearings over this period. Copyright (c) 2014 John Wiley & Sons, Ltd.