Experimental and numerical investigation on fire performance of hollow-cavity ceramsite concrete wall-panel

To investigate the fire performance of hollow-cavity ceramsite concrete wall-panels (HCCCW), this study conducted one-sided fire tests on four HCCCWs. The experiment yielded results on their thermal response, fire resistance, and out-of-plane deformation, providing insights into the heat transfer mechanism of HCCCWs under one-sided fire exposure. An analysis of the distribution characteristics of section temperature fields and temperature gradients was performed by establishing finite element (FE) models. Based on the validated models, parametric studies were conducted on hollow-cavity area, volume-cavity ratio, ceramsite concrete density, and type of filling material. The results indicate that as the volume-cavity ratio increased from 23.55 % to 35.00 %, the duration of steam escape from the unexposed surface decreased by 43.75 % and the number of cracks on the fire-exposed surface decreased by 58.97 %. In the temperature-time curve for the unexposed surface of HCCCW, both the duration of heat front propagation and temperature plateau increase with a decrease in volumetric cavity ratio and cavity surface area. Compared to heat conduction in ceramsite concrete, cavity radiation significantly improves heat transfer efficiency. Additionally, the temperature at the center of the cavity is approximately 20 % higher than at its midpoint along with webbing. Decreasing hollow-cavity area and volume-cavity ratio or increasing ceramsite concrete density effectively enhances HCCCW's fire resistance. Considering structural weight, material cost, and fire resistance, filling cavities with rockwool proves to be most cost-effective.