Experimental Tests of a Real Building Seismically Retrofitted by Special Buckling-Restrained Braces

Abstract

Buckling Restrained Braces (BRBs), differently from conventional braces, do not exhibit appreciable difference between the tensile and compression capacity and no strength degradation of brace capacity under compressive and cyclic loading. Since lateral and local buckling behaviour modes are restrained, large inelastic capacities are attainable. Hence, BRBs may represent an efficient and reliable solution for reducing the seismic vulnerability of buildings. Results of experimental tests on the response of a real two‐story reinforced concrete (RC) building equipped with BRBs are presented and discussed. The considered BRBs are a special ‘only‐steel’ version of the more common ‘unbonded braces’. In particular, two different BRBs have been tested. Both of them are detachable “only‐steel” devices, consisting in a rectangular steel plate and a restraining steel sleeve. The latter is composed by two omega shapes which are bolted together. The main characteristic of the braces consists in the possibility to hide them within the space between the facing and the backing of masonry infill walls commonly used for RC buildings.