Fire resistance performance of multi-ribbed composite walls
To investigate the fire resistance performance of multi-ribbed composite walls,two full-scale multi-ribbed composite walls were subjected to single-and double-sided fire tests,respectively.The temperature fields,displacements,fire resistances and failure modes of the walls were obtained.It is observed from the test that,under single-sided fire,a significant temperature gradient formed inside the wall along the thickness direction.When damaged,the temperatures of the autoclaved aerated concrete blocks and the concrete of the ribbed beams and ribbed columns on the surface unexposed to fire are 90 ℃ and 109 ℃,respectively.The failure mode is compressive-bending instability caused by thermal bending.For the wall under double-sided fire,a low temperature area is formed at the center along the thickness of the autoclaved aerated concrete blocks.When the wall fails,the temperature in this area is 193 ℃.The failure mode is axial compression failure caused by material strength degradation.Therefore,there is a significant temperature gradient between the autoclaved aerated concrete blocks inside the wall and the concrete of the ribbed beams and ribbed columns under both fire conditions.The interfacial cracking between the autoclaved aerated concrete blocks and the concrete of ribbed beams and columns has a negligible effect on the integrity of the walls.Under an axial compression ratio of 0.5,the walls under single-and double-sided fire conditions reach the fire resistances of 181 min and 91 min,respectively.The finite element model of multi-ribbed composite wall was established and a parametric study was conducted considering the axial compression ratios and fire conditions.It is found that the peak of thermal expansion of the multi-ribbed composite wall decreases as the axial compression ratio increases.When subjected to the same axial compression ratio and fire time,the axial thermal expansion of the wall under double-sided fire is larger than that under single-sided fire.
multi-ribbed composite wallsingle-sided firedouble-sided firefull-scale fire testfinite element analysisfire resistance
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维普
