Ductility Behaviour of Bamboo Reinforced Coconut Shell Concrete Beams

This paper presents the study on the ductility behaviour of bamboo reinforced coconut shell aggregate concrete beams together with normal weight concrete beams (NWCB). The grade of coconut shell aggregate concrete, a lightweight concrete (LWC) produced using coconut shell aggregate got from an agricultural waste as lightweight aggregate, referred to hereafter as CSC was 20N/mm2 at 28 days. The grade for normal weight concrete was 20N/mm2 using conventional stone aggregates. The beams prepared for study were of size 150 mm x 250 mm x 1500 mm and tested in flexure for the behaviour. Two beams were of normal weight concrete with steel reinforcement (NWCB), two beams were of CSC with steel reinforcement (CSCB), two beams were of CSC with split bamboo as reinforcement (BCSC) and two beams were of CSC with split bamboo wrapped with binding wire as reinforcement (BCSCB) - totally eight beams were tested and their behaviour was reported. From the experimental results, it was observed that the load carrying capacity of the NWC beams were higher than that of CSCB, BCSC, and BCSCB beams. The stiffness behaviour of CSCB beam showed similar trend as that of NWC up to failure. Energy absorption for BCSC beams are higher than that of NWCB, beams, CSCB and BCSCB beams. CSCB beams also exhibited a lot of cracking thus the crack width and crack spacing was small. The CSCB, BCSC and BCSCB beams exhibited higher deflection under constant load until failure, compared to NWC beams. Higher concrete strains for the reinforcement in the CSCB shows stronger bond between CSC and the reinforcement.