Seismic behaviour of interior reinforced-concrete beam–column sub-assemblages with engineered cementitious composites

Abstract

The feasibility of using engineered cementitious composites (ECC) in joint cores of reinforced-concrete (RC) beam–column sub-assemblages as a means to enhance seismic behaviour is evaluated. Four RC beam–column sub-assemblages are constructed and tested under lateral cyclic loading. One RC beam–column sub-assemblage with normal concrete in the joint and one RC sub-assemblage with ECC in the joint are designed to gravity loads; neither type has transverse reinforcement in the joint core. Similarly, one RC sub-assemblage with normal concrete in the joint and one with ECC in the joint are designed for seismic provisions, but the latter has no transverse reinforcement in the joint. The test programme thereby allows direct comparison of the structural performance of ECC joints with concrete joints for beam–column sub-assemblages for both gravity and seismic design situations. Results show that the use of ECC joints significantly changes the behaviour of the joint from brittle to ductile. Both ECC specimens exhibit superior damage tolerance, with limited shear distortion and multiple fine cracks in the joints, even though no transverse reinforcement is provided in the joint. Moreover, specimens with ECC joints demonstrate improved bond behaviour in early loading cycles.

Compression and Flexural Behavior of ECC Containing PVA Fiber

“…A compatible deformation and improved bond-slip behavior were also observed in steel-reinforced ECC (Lee et al, 2016). With all these reliable features, ECC is suitable for earthquake resistance structures, as demonstrated by previous studies (Qudah & Maalej, 2014;Said & Razak, 2016;Lee et al, 2018a). In addition, ECC can be designed to cater to different functionalities, such as self-sensing and self-healing, as it is subjected to different types of loading and different exposure conditions or environments.…”

The Effect of Elevated Temperature on Engineered Cementitious Composite Microstructural Behavior: An Overview

“…The use of ECC has expanded dramatically over the last decade and has been used in a number of systems, such as high-rise buildings (Yang et al, 2021), bridges (Zhang et al, 2021), tunnels (Huang et al, 2021), highways (Guan et al, 2021) and other infrastructures. ECC is suggested in strengthening beam-to-column connections that are recurrently exposed to cyclic loading, a continuous and repeated loading, such as fluctuating stresses, strains, and forces, seismic actions (Lee et al, 2018;Qudah & Maalej, 2014). The ECC-concrete beams with ECC application at the tension region, when subjected to flexural load, displayed a substantial improvement in flexural strength and ductility, proven under both the experimental and theoretical aspects (Yuan et al, 2020;Zhang et al, 2006).…”

The Behavior of Interior Beam-Column Joint Models Using Self-Compacting Concrete with Variations of Shear Reinforcement Subjected to Cyclic Lateral Loads

“…The provisions in designing beam-column joints as parts of earthquake-resistant structures emphasize three main aspects. Those are shear strength, the need for transverse reinforcement, and the behavior of beam and column connections that pass through the joints [9].…”

“…The nature of dynamic loading is loading and unloading [11]. As the horizontal displacement increases, more cracks are formed along with the structural elements, depending on the direction of loading [9]. The propagation of crack causes the degradation of stiffness and strength as well as the number of cyclic loads due to the earthquake.…”