Experimental investigation on axial compression behavior of laminated bamboo lumber short columns confined with CFRP

In order to study the axial compression behavior of short columns confined with carbon fiber reinforced polymers (CFRP), 21 specimens were tested under monotonic loading. Four failure modes were classified based on the test results which were adhesive layer failure, compression failure, buckling failure and local buckling failure. With the improvement of external reinforcement effect, the failure mode changed from compression failure to buckling failure or local buckling failure. With the increase of cloth ratio, the ductility and ultimate bearing capacity of the specimens increased, but not linearly. However, the increase range gradually decreased even the cloth ratio kept increasing. When the cloth ratio reached 2.56%, the ductility reached the maximum. The lateral deformation of laminated bamboo columns was restricted by CFRP during compression, thus lateral strain and Poisson's ratio gradually decreased with the increase of cloth ratio. Stress-strain model and formula for calculating the compressive strength of reinforced columns were proposed which gave a good agreement with the test results.