ANALYSIS OF FIRE RESISTANCE PERFORMANCES ON DOUBLE-STEEL-PLATE CONCRETE COMPOSITE WALLS WITH DIFFERENT FIRE PROTECTION MEASURES

Double-steel-plate concrete (DSPC) composite wall is increasingly used in high-rise residential buildings, but there is no corresponding fire protection standard. In the paper, autoclaved lightweight concrete plate (ALC plate) and non-expansive fire retardant coatings were used to protect the structure. By using ABAQUS to establish the DSPC composite wall models under different working conditions, this paper simulated the temperature distribution and deformation of the structure and analyzed its fire resistance, which was under the combined action of axial compression with unilateral ISO-834 standard heating curve. It was found that with the increase of fire time, the temperature gradient became smaller and smaller, and the temperature difference value between middle part of concrete and steel plate of fire surface was more than 67% from 30 min to 180 min; increasing the distance between studs and split bolts would increase axial expansion deformation and axial compression deformation of the wall at the beginning of the fire; when the height-thickness ratio was greater than 16, the change of the height-thickness ratio had no obvious effect on the axial expansion displacement value under 180 min; increasing the axial compression ratio would reduce the axial expansion displacement of the wall at the initial stage of fire, and the axial compression deformation would be increased under the same temperature. Using 20 mm ALC board or 10 mm non-expansive fire-retardant coating to protect the composite wall, the temperature of structure could not reach the critical temperature. The results showed that the thickness of the fire protection layer of the composite shear wall could be further optimized.