Lateral cyclic performance of bamboo reinforced concrete columns with pilecap systems and incorporated rebar strengthening

This research investigated the effect of strengthening in bamboo-reinforced concrete (CB) columns with pilecap systems by incorporated rebar to improve seismic performance as well as prevent cracking and early failure. The parameters observed were lateral load capacity, drift ratio, relative energy dissipation and collapse patterns. The test specimens consisted of 6 bamboo-reinforced concrete columns with a reinforcement area ratio (ρ b ) of 6 %. Among these specimens, three columns were strengthened with 6 mm steel (B6) and another with 8 mm steel (B8). The control specimens were bamboo-reinforced concrete columns without strengthening (CB) and steel-reinforced concrete columns (CS), with a reinforcement area ratio of 6 % and 1.4 %, respectively. Each column was tested and subjected to cyclic lateral loads according to ACI 375.1–19 and ASTM 2126–19 with a constant axial load of 54.85 kN. B6 and B8 had greater lateral load capacity, stiffness, ductility and drift ratio than CB and CS. B6 and B8 achieved an energy dissipation ratio greater than CB and almost the same as column CS. These results suggest that the connection points of bamboo-reinforced concrete column-foundation or beam-column connections should be reinforced to improve seismic performance. The application of bamboo-reinforced concrete portal structures in simple rural houses will require strengthening at the connection points to ensure livable and technically safe houses. • The rebar strengthening innovation in bamboo-reinforced concrete column-foundation relationship for simple houses. • The strengthening of reinforcement in bamboo-reinforced concrete columns with a reinforcement area ratio ρ b of 6 % can increase horizontal load capacity to approximately 46 % when compared to CS with a steel reinforcement area ratio ρ s of 1.4 %. • The strengthening of reinforcement in bamboo-reinforced concrete columns can increase horizontal load capacity to approximately 65 % when compared to bamboo-reinforced concrete columns without strengthening.