Structural Behaviour of Bamboo-Reinforced Concrete Beams: A Laboratory Study

The search for cost-effective and locally available alternatives to conventional steel reinforcement has intensified in recent years, with bamboo emerging as a viable candidate in low-cost construction applications across sub-Saharan Africa. This study investigates the structural behaviour of bamboo-reinforced concrete beams under flexural loading through a controlled laboratory experiment. Bamboo culms of the Bambusa vulgaris species, sourced from plantations in Anambra State in the South East geopolitical zone, were prepared as reinforcement members with varying treatment conditions: untreated, varnish-coated, and epoxy-sealed. Twelve beam specimens of 150 mm by 200 mm cross-section and 1,500 mm span were cast and subjected to four-point bending tests after 28-day curing, in accordance with BS EN 12390-5. Load-deflection responses, crack patterns, and ultimate failure loads were recorded and compared against equivalent steel-reinforced beams of identical geometry. Results indicate that epoxy-sealed bamboo-reinforced beams achieved approximately sixty-two percent of the ultimate flexural capacity of steel-reinforced equivalents, while untreated bamboo beams performed significantly lower at forty-one percent due to moisture absorption and slip at the bamboo-concrete interface. Failure modes in bamboo-reinforced beams were predominantly tension-controlled, with no premature compression failure observed. The study concludes that treated bamboo reinforcement offers structural promise for single-storey construction applications where steel supply is limited, provided adequate bonding treatment is applied. Keywords: bamboo reinforcement, concrete beams, flexural behaviour, alternative reinforcement, sustainable construction.