Seismic behaviour of thin/slender concrete walls with monolithic emulation base connections tested on shaking table

Abstract

Two geometrically identical slender precast concrete walls with monolithic emulation base connections were constructed and tested under biaxial loading using two clover displacement control patterns on shaking table. Specimen 1 was constructed with 1.27% longitudinal reinforcement bars which exceeding the requirement in BS 8110 and NZ 3101 while Specimen 2 was 0.54% longitudinal reinforcement bars within the range specified in BS 8110 and NZ 3101. Both specimens were subjected to quasi-static bilateral loading which was supplied by hydraulic double actuator. In-plane and out-of-plane drifts were applied to both specimens using Lissajous functions. Specimen 1 was subjected to 0.5%, 1.0% and 1.5% drift within two cycles in each drift. This wall failed in lateral torsional buckling mechanism with ductility of 3. Specimen 2 was tested at 0.5%, 1.0%, 1.5% and 2.0% drift. This specimen started to crack at 0.5% and more cracks were observed at 1.0% drift. This wall failed by low cycle fatigue behaviour associated with compression failure at the bottom of the wall with ductility of 4. It can be concluded that even though the slenderness ratio (height/thickness) is limited to 30 but experimental result showed that slenderness ratio 60:1 is still stable under biaxial loading. Experimental results showed that an increase of longitudinal reinforcement did not attribute to better seismic performance of thin/slender precast wall panels.