Experimental study of performance of engineered bamboo beams exposed to three-sided standard fire

Abstract

This paper presents a pilot experimental study aimed at evaluating the performance of engineered bamboo beams exposed to and following exposure to three-sided standard fire conditions. Nine tests were carried out including two constant applied load fire tests and seven flexural tests of engineered bamboo beams following exposure to fire. Test parameters include load ratio in fire tests, fire exposure duration, beam geometry and engineered bamboo type. Two engineered bamboo products: laminated bamboo and bamboo scrimber, commonly used in construction were considered. In all cases, regardless of fire exposure, the failure mode was flexural failure associated with tensile fracture of the extreme tension fibre. The stiffness and ultimate loads of engineered bamboo beams were observed to decrease with increased fire time and the strain distribution at the mid-span cross-section remained linear after exposure to the standard fire. The fire resistance of laminated bamboo beams decreased with increased applied load. Charring depth was measured for all beams after tests and equivalent charring rate was calculated. Result shows that laminated bamboo beams had a higher charring rate than the denser bamboo scrimber beams. Both sectional analysis and simplified methods based on the reduced cross-section method are used to determine the fire resistance and ultimate load capacity of the engineered bamboo beams following exposure to fire.