An extensive experimental investigation was performed to understand the seismic behaviour of the beam-column joint when sustainable materials are used. The study focused on the joint between encased concrete-filled steel tubular (ECFST) columns and reinforced concrete (RC) beams, using concrete with fly-ash and steel fibres. Continuity issues in longitudinal reinforcement at the joints were addressed with pre-fabricated steel loops. Seismic characteristics studied include hysteresis behaviour, lateral load capacity, ductility, energy dissipation capacity, rigidity degradation, and brittleness index. Results indicate steel loops and addition of fly-ash and steel fibres substantially improve seismic performance, with minimal compromise in lateral load capacity, reducing CO2 emissions and utilizing industrial waste. © 2020 Elsevier B.V., All rights reserved.