Evaluation of RC Special Structural Walls Reinforced with Cold-Rolled Ribbed Steel Bar Welded Mesh under Axial and Lateral Loads

Abstract

Cold-rolled ribbed steel bar welded mesh (CRWM) is used to speed construction and improve the quality of the reinforcing. However, the seismic performance of such RC walls is uncertain. The current study assessed the seismic efficacy of these walls by analyzing the effects of different combinations of axial and cyclic lateral loading in a large-scale experimental program. The walls were built with boundary elements at the ends and two layers of mesh placed into the web of the walls. The seismic parameters comprise a force-displacement hysteresis curve, concrete and rebar strains, dissipated energy, and stiffness. The experimental findings show that the axial load had a significant effect on the deformation capacity, strength, and failure mode of the wall. Except for walls with flexural failure, the study revealed that the use of such mesh had a detrimental effect on the cyclic performance of other specimens. In walls exhibiting flexural failure modes, such as C15, the use of CRWM slightly improves ductility compared to the ASCE 41-17 proposed model. The use of such mesh in walls with any type of shear failure mode had a significantly negative influence on the seismic performance of the walls. Among shear failure modes, sliding shear failure is particularly adverse. In such failures, the vertical rebars are subjected to deformation perpendicular to their direction. Because of their brittle nature, they cannot accommodate this deformation and are prone to fracture. Moreover, a comparison of the experimental backbone curve of the walls and the numerical model proposed by ASCE 41-17 revealed that the ASCE model tended to overestimate the effective stiffness of walls with axial loads of less than 10% fc′Ag. The structural integrity of buildings is critical in seismically active areas. This study looks into the use of cold-rolled ribbed steel bar welded mesh (CRWM) in the web of reinforced concrete special structural walls, a technique used in Turkey and China that is also being considered in Iran. Because of a lack of performance data, current building codes, such as ACI 318-19, do not include provisions for CRWM in seismic systems. Our research attempts to fill this gap, which provides empirical data from large-scale experimental tests to evaluate the cyclic performance of walls with CRWM under various axial loads. The findings provide important insights into the behavior, strength, and ductility of such walls, allowing for a better understanding of their use in earthquake-prone areas. The findings are intended to inform and potentially influence building codes and practices, advocating for the use of CRWM where it can improve construction efficiency and seismic resilience. This research not only helps to optimize structural designs but also helps to develop safer, more cost-effective building strategies in seismically active areas.