Abstract:
Understanding the out‐of‐plane response of masonry infill walls and preventing
their progressive collapse mechanisms is very important for earthquake‐prone
countries to prevent loss of life and economic loss. In fact, having a realistic collapse
mechanism assessment allows suitable prevention measures to be adopted. With
this purpose in mind, two full‐scale one‐bay one‐story substructures of reinforced
concrete frames (RCF) with infill walls were tested on a shake table. These 2 specimens
were designed to represent the response of a typical RC Frame at the fifth
floor of an 8‐story building, namely the out‐of‐plane failure of its infill wall under
combined bidirectional seismic load. Both specimens were composed of a singleleaf
clay brick infill wall surrounded by the RC Frame. However, while the first
specimen corresponds to an unreinforced masonry configuration, the second specimen
includes horizontal bed joint reinforcement as a strengthening/retrofitting
technique. The main novelty of this study is the application of a bidirectional and
simultaneous dynamic loading to the specimen, such that in‐plane and out‐of‐plane
effects are evaluated together. This work presents several interesting experimental
results, with particular emphasis on the bearing capacity of the specimens against
out‐of‐plane failure. As expected, the in‐plane capacity of the reinforced infill specimen
is larger than that of the unreinforced infill specimen. Nevertheless, the
out‐of‐plane bearing capacities of the two specimens are very similar, in contrast
to their ductility capacity, which is significantly increased in the reinforced masonry
specimen. The capacities of the two specimens for both in‐plane and out‐of‐plane
directions, as predicted by formulations in the literature, are given. The differences
found between these calculations and the results of the tests are discussed, andmay
possibly be explained by the parameters considered in the different formulations.