Performance of special RC shear walls under lateral cyclic and axial loads

• Published in: Engineering structures 2023-11, Vol.295, p.116813, Article 116813
• Main Authors: Bastami, Morteza, Salehi, Mohsen, Ghorbani, Masoud, Moghadam, Abdoreza Sarvghad
• Format: Article
• Language: English
• Subjects: Axial load; Lateral cyclic load; Special RC shear wall; Special structural wall
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2023.116813

•Increasing the axial load from zero to 10 percent, resulted in an increase in ductility and lateral resistance; however, increasing the axial load to 15 percent reduced ductility by 10 percent.•ASCE41-17 overestimates the displacement corresponding to maximum resistance.•The stiffness calculated using the effective stiffness coefficient proposed by ACI318-19 and ASCE41-17 is greater than the experimental stiffness.•The effective stiffness of the wall increased as the axial load increased.•Following failure types dissipates more energy respectively: tension control flexural, compression control flexural, sliding shear. Reinforced concrete (RC) shear walls are common structural elements, although their cyclic behavior under different combinations of axial and lateral loading requires further study. The boundaries of flexural-dominated walls experience the greatest stress and strain; thus, rebar layouts are vital in this area and have significant effects on the cyclic behavior of a wall. In the current study, three full-scale walls were designed and constructed using the ACI318-19 special structural wall criteria with boundary elements placed at each end of the wall. Cyclic testing was performed on RC shear walls for different lateral and axial load combinations. These large-scale tests showed how axial loads affect the seismic performance of special RC shear walls. The seismic parameters of the force–displacement hysteresis curves, concrete strain, rebar strain, dissipated energy and stiffness are presented and discussed. The experimental findings demonstrate the effect of axial loading on the wall deformation capacity, strength capacity and mode of failure. Experimental backbone curves for numerical models of walls as recommended by ASCE41-17 revealed that the ASCE model overestimates the effective stiffness of walls with axial loads of less than 10% fcAg, A four-line model is proposed to estimate the force–deformation relationship. It is demonstrated that the effective stiffness coefficient should be a function of the axial load ratio.