Advancing seismic resilience: Performance-based assessment of mid-rise and high-rise engineered cementitious composite (ECC) Buildings

Engineering Cementitious Composites (ECC) have received wide attention in recent years due to their enhanced mechanical properties and ductility. These properties offer an opportunity to design structures with significantly improved seismic performance having a low-damage and ductile response. However, existing research studies primarily focus on the performance of ECC at material and member scales, resulting in a knowledge gap regarding its response at the structural level. This study examines the system-level seismic response of buildings designed using ECC and compares their performance with those having conventional reinforced concrete (RC) members. For this purpose, two RC shear wall buildings (7-story and 24-story) were selected as a case study, and their elements were separately designed (for the combined gravity and lateral loads) as RC and ECC elements using the guidelines recommended by the Japan Society of Civil Engineering (JSCE) and ACI (American Concrete Institute)-318-19. The design results show that the requirement of longitudinal steel is reduced by a maximum of 24% in ECC flexural members and by 15% in compression members, in addition to a significant reduction in the required transverse reinforcement as compared to the corresponding RC members. Similarly, owing to improved tensile behavior, the ECC members also exhibited a higher shear capacity than RC members. The detailed nonlinear finite element models of the case study buildings (for both the design cases i.e., ECC and RC) were subjected to monotonic and reversed-cyclic pushover analysis, and nonlinear time history analyses (NLTHA) under a set of selected ground motions. It was observed that ECC structures exhibited significantly improved lateral capacity, revered-cyclic response, and overall seismic performance as compared to the corresponding RC structures. These results demonstrate that ECC can be effectively used to design various members for improved seismic performance of buildings.