Experimental Study on the Fire Resistance Performance of Bubble Beams under Standard Fire

A bubble system has several benefits, including increased structure efficiency, reduced material consumption, lower overall cost of the structure, decreased construction time, and green technology. This research aims to evaluate the behavior of a reinforced concrete bubble beam exposed to elevated temperatures of 600 °C and 800 °C for 2 hours. It utilizes varying bubble diameters of 90 mm and 120 mm, with the bubbles having been placed in the core of the beams, where the stress in the neutral axis is zero. The experimental results revealed that, after being exposed to fire reaching 600°C for 2 hours, the beams with void diameters of 90 mm and 120 mm presented a reduction in flexural strength of 22.35% and 18.58%, respectively. However, after fire exposure at 800°C for the same time the reduction was 31.76% and 32.74%, respectively. The findings of the experimental study indicated that the beams’ stiffness was decreased under the influence of fire, whereby elevated temperature exposure contributed to larger deformations and the formation of cracks.