Analysis of confined AAC walls under monotonic compression

Abstract

Confined walls are structures frequently encountered in seismic zones. They have been put to numerous tests over time, including entire buildings being tested under cyclic loading. However, the observed trend is that confined masonry structures are also built in areas of little or no seismic activity. The draft 2nd edition of Eurocode 6 even brings about calculation procedures for confined walls erected outside active seismic regions. That said, an insufficient number of tests have still been performed on confined masonry structures under monotonic load, a situation which has a considerable negative impact on the verification process regarding standard recommendations. This paper presents results obtained from tests carried out on 20 walls, both non-confined and with reinforced concrete confinement. The full-scale walls put to tests were built of autoclaved aerated concrete (AAC). They were subjected to one loading cycle until failure. The testing procedure involved numerical simulations and calculations based on data obtained from the strut-and-tie models, as well as calculations carried out in accordance with the procedures laid down in the draft 2nd edition of Eurocode 6. It was demonstrated during the tests that wall confinement has a significant impact on the masonry resistance under monotonic load. The numerical models were used to determine the distribution of stresses in the test walls and to select the effective strut-and-tie model. The authors of the paper also verified the standard recommendations.