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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.All peak measured quantities for the seven input earthquakes are listed in Table II. The table also shows the peak response of the corresponding 5% damped fixed-base structure. The structure, which was fixed at the base, did not yield during the seismic events. The measurements listed in the table indicate adequate capacity of the proposed technology in reducing the seismic demand on the structure.The response reductions in terms of interstory drift and top floor acceleration for each ground motion are shown in Figure 6. For the seven records, an average reduction of 55% was measured for the roof acceleration (i.e., columns shear), whereas an average reduction of 33% was determined for the interstory drift. The tests indicated different performances of the bearings with increasing energy content of the seismic events at the isolator's frequency. For instance, for both Campania records (CAM and CAT), significant reduction in the top floor acceleration (almost 60%) was observed. Figure 9. Amplification envelopes: isolated building versus 5% damped structure. RECYCLED RUBBER-FIBER-REINFORCED BEARINGS

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Energy dissipating devices, such as metallic ductile dampers, could represent one reliable system for seismic performance upgrading of reinforced concrete (RC) structures. This paper illustrates the significant improvement to the seismic response of RC structures equipped with dissipative bracing systems, such as eccentric braces (EBs) and buckling restrained braces (BRBs). In fact, the results of experimental tests carried out on two similar two‐storey one‐bay RC structures, respectively equipped with EBs and BRBs, are described. Referring to EBs, 3 lateral loading tests have been performed. Each test is characterized by shear links with bolted end‐plate connections. Different design criteria have been applied in the design of the connections. In the first test, capacity design criteria have not been considered. In the second test, a capacity design criterion has been applied, with a link shear over‐strength factor equal to 1.5. In the third test, a design criterion similar to the one adopted for the second test has been implemented, but with a larger over‐strength factor. In case of BRBs, two types of ‘only‐steel’ braces have been tested: one type was made using two buckling‐restraining rectangular tubes that are fully welded together with steel plates; the other type is detachable, being made again with two buckling‐restraining rectangular tubes but joined together by means of bolted steel connections. In both cases, the internal yielding core was a rectangular steel plate. The experimental results of both bracing systems are encouraging about the possibility to use these devices for improving the seismic resistance of existing RC structures. Santrauka Didinant gelžbetoninių pastatų atsparumą seisminiams poveikiams, gali būti naudojami energiją sugeriantys metaliniai slopintuvai. Straipsnyje parodoma, kaip tokios slopinančios sistemos, kaip necentriniai ryšiai ir klupimą suvaržantys ryšiai, gali iš esmės gerinti pastato seisminę elgseną. Pateikiami dviejų panašių vienos angos gelžbetoninių pastatų su minėtaisiais ryšiais eksperimentiniai tyrimų rezultatai. Tyrimai parodė, kad abi suvaržymo sistemos gerina eksploatuojamų gelžbetoninių pastatų atsparumą seisminiams poveikiams.

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