This paper details the findings of an experimental program that assessed the seismic performances of a novel low-cost base isolation device. The proposed bearings are referred to as recycled rubber–fiber-reinforced bearings (RR-FRBs). Devices composed of a low-cost recycled elastomer and reinforced with fiber sheets were manufactured and tested. The main revolutionary concepts investigated in this study are as follows: low-performance elastomers can be used to produce rubber isolators, and vulcanization can be prevented by bonding different layers with an elastic compound. This study addresses all design and technical aspects related to the implementation of the proposed base isolation system. Shaking table tests showed a significant improvement in the seismic performance of an RR-FRB isolated building with respect to a corresponding fixed-base structure. Copyright © 2014 John Wiley & Sons, Ltd.

In this paper, analysis of the shaking table tests performed on a four storey, large-scale, steel mock-up, equipped with a bracing system including magnetorheological (MR) dampers operating both in passive and semi-active (SA) ON–OFF mode, is presented. The adopted SA control algorithm is derived from an ‘energy-based’ instantaneous optimal control process. After having described the testing set-up and the control algorithm, a critical overview of the experimental results is reported. In particular, by using SA-controlled MR dampers, large response reductions, with respect to the corresponding passive (ON state) control configuration, may be obtained both in terms of relative displacements (drifts) and absolute accelerations. Moreover, it is experimentally confirmed that use of SA control, not only reduces the maximum values of the considered response quantities, but extends the improvements to the complete time-histories. This satisfactory performance is obtained, even if some particular (and undesired) types of behaviour, shown and explained in the paper, have been detected during the test campaign. In order to completely understand the dynamical behaviour of the controlled structure and to predict its response, a detailed analytical model of the controlled mock-up is proposed and validated. Copyright © 2004 John Wiley & Sons, Ltd.