Application of Engineered Cementitious Composites (ECC) in interior beam–column connections for enhanced seismic resistance

• Ultimate load of specimens incorporating ECC was greatly enhanced.
• ECC imparted to the specimens greater ability to resist reverse cyclic loading steps.
• ECC specimens exhibited higher energy absorption capacity compared to the control.
• ECC specimens showed ductile failure mode triggered by plastic hinging in the beams.
• ECC specimens showed reasonable safety against shear stress-induced joint failure.

This study aims to evaluate the feasibility of using ultra-ductile Engineered Cementitous Composites (ECC) as a means to enhance the performance of beam–column connections. Nine one-third scale specimens, consisting of type 2 (ACI352R-02) interior connections at a zone of high seismicity (UBC-zone 3), were tested under reverse cyclic loading, simulating seismic excitation. The joints of these specimens were typical in geometry and main reinforcement detailing to specimens of a prototype building frame designed according to ACI318-08. The primary variables were the amount and arrangement of transverse reinforcements, and the materials within the plastic zone of the connection.The performances of a series of ECC-enhanced beam–column interior connections were compared to that of a control concrete counterpart to evaluate the benefits of using ECC in this type of application. The column load–displacement response (including the ultimate load and ultimate displacement), the (hysteresis) energy absorption capacity, and the cracking response were used as criteria in the comparison.The test results indicated that the use of ECC material in the connection plastic zone as a replacement of concrete and partial replacement of transverse (confinement) reinforcement can significantly enhance the joint shear resistance, energy absorption capacity, and cracking response, thereby, enhancing the joint seismic resistance and reducing reinforcement congestion and construction complexity.