Fire behavior of H-shaped steel reinforced reactive powder concrete columns

This paper presents the fire resistance behavior of steel reinforced reactive powder concrete (SRRPC) columns. The main factors of section size, axial load ratios, reinforcement ratios, and heating-surface number on the fire resistance of SRRPC column were considered. The findings showed that surface color of the columns changed from gray to gray white after fire. Vertical and horizontal cracks were found on the surface of the specimens. The quantity of small cracks is greater than that of large cracks, and concrete cracking phenomenon was found in some specimens. The failure time increased by 44.24 % as the section size increased from 180 × 180 mm to 260 × 260 mm. The failure time decreased by 105.12 % as the axial load ratios increased from 0.2 to 0.6. The failure time improved by 8.82 % as the reinforcement ratios increased from 0.479 % to 1.55 %. The failure time decreased by 27.25 % when the heating-surface number increased from 1 to 4. With the increase of axial load ratios, heating-surface number and the decrease of section size, reinforcement ratios, the fire resistance was reduced. The influence degree of each parameter on the fire resistance in descending order are axial load ratios, section size, heating-surface number and reinforcement ratios. Finally, a simplified calculation method of the fire resistance was proposed, which offers a reference for evaluating the fire resistance of SRRPC constructions in fire.