Hybrid Simulation Tests of Real-Scale Squat Reinforced Concrete Shear Wall Specimens

Squat reinforced concrete shear walls usually have diagonal shear- or sliding shear-controlled behavior. Due to the lack of experimental data, there is uncertainty on how squat wall design parameters define their behavior modes. Two real-scale tests were conducted at ETH Zurich on specimens of equal geometry and reinforcement, but different axial load ratios (ALR), employing hybrid simulation techniques to apply recorded ground-motion excitation in a quasi-dynamic manner. Specimen HSW01 had an ALR of 4.02%, whereas the ALR for Specimen HSW02 was 8%. Specimen HSW01 failed in sliding shear, exhibited a quasi-ductile behavior, developed a peak resistance of 2,730 kN, and reached a displacement corresponding to a 3% drift ratio without losing the ability to carry its axial load. Specimen HSW02 failed in shear diagonal compression and lost the ability to carry its axial load at a horizontal displacement corresponding to a 2% drift ratio and a peak resistance of 3,360 kN. The crack patterns, crack width, and damage progression observed in both tests are presented. Finally, the results were compared with similar specimens tested using a displacement-driven incremental symmetric quasi-static cyclic test protocol. Hybrid simulations using recorded ground-motion excitation did not affect the failure mode of the specimens but allowed them to sustain larger displacements than those tested cyclically.