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Title |
Seismic Performance of Masonry Walls Strengthened by an Engineered Cementitious Composite Jacket
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Authors |
안강우(Kang-Woo An) ; 채유진(Yu-Jin Chae) ; 엄태성(Tae-Sung Eom) ; 김진우(Jinwoo Kim) ; 김선웅(Seon-Woong Kim) ; 김재환(Jae-Hwan Kim) |
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DOI |
https://doi.org/10.4334/JKCI.2023.35.4.397 |
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Keywords |
비보강조적; 조적벽; ECC 자켓; 강체회전; 내진보강 unreinforced masonry; masonry wall; ECC jacket; rocking; seismic retrofit |
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Abstract |
In this study, the seismic performance of unreinforced and strengthened masonry walls was experimentally evaluated, taking into account the masonry conditions typically found in old buildings in Korea. Masonry conditions unfavorable to seismic performance, such as cavities between interior and exterior masonry layers, poor mortar joints, and the presence of openings, were considered. For strengthening, an engineered cementitious composite (ECC) jacket, using fiber-reinforced mortar with a thickness of 40 mm, was applied on the exterior surface of the masonry walls. Cyclic load tests were conducted on three unreinforced walls and three jacketed walls, focusing on the strengthening effect of the ECC jacket, including failure modes and behavior. Rocking mode was confirmed as the governing behavior mode in both unreinforced and jacketed specimens, while failure modes included joint tensile failure at the brick-mortar interface, toe crushing, and diagonal tensile cracking around the corners of the openings. The presence of openings altered the failure mode of the masonry walls and reduced their seismic performance in terms of strength and ductility. However, the effects of the cavity between masonry layers, poor mortar joints, and eccentric jacketing on seismic performance were found to be minimal or limited. The ECC jacket, which was securely connected to the upper and lower concrete beams using post-installed anchors, showed integrated behavior with the masonry wall. Consequently, the jacketed specimens exhibited improved strength, stiffness, ductility, and energy dissipation capacity.
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