A Large‐Scale Test of a Reinforced Concrete Core Wall Subjected to Three‐Dimensional Loading

ABSTRACT This paper presents a large‐scale quasi‐static test of a reinforced concrete (RC) core wall under high axial compression force and bidirectional lateral cyclic loads. A virtual 33‐story RC frame‐core wall prototype building was designed per the current Chinese codes, and RC core walls at the lower stories were selected as the substructure for experimental testing. Using a 108 MN spatial loading facility, three‐dimensional loading (including axial compressive force, bidirectional shear forces, and bidirectional overturning moments) was applied to the test structure to investigate the spatial resisting mechanism and seismic behavior of the core wall structure. During the test, the core wall specimen sustained brittle failure at 0.9% drift (corresponding to a top lateral drift of 1.34% for the 33‐story prototype structure) due to the large compressive strain demand (−0.008) in the unconfined region of flange walls. Out‐of‐plane diagonal compression cracks penetrated the entire sectional length of the flange wall, but no sliding behavior was observed before significant concrete crushing. Furthermore, the measured vertical strain distribution revealed no obvious shear lag effect in the flange walls, indicating an evident spatial resisting mechanism of the specimen. Current design codes including NZS 3101:2006 (provisions for nominal strength), JGJ 3‐2010, and AIJ standard for the design and calculation of reinforced concrete box‐shaped wall structures underestimated the effective flange width of L‐shaped walls in the test core wall structure. When the core wall test substructure was subjected to DBE‐level and MCE‐level loading in one lateral direction, inducing compression in one coupled wall and tension in the other, the coupled wall under compression subsequently carried 63% and 86%, respectively, of the total base shear force during loading in the perpendicular lateral direction. Such a significant shear force redistribution among various coupled walls in a core wall should be taken into consideration in the design of tall buildings.