Abstract
PurposeConventional plasterboard linings impose a hard limit on the fire resistance of light steel frame (LSF) walls because gypsum rapidly degrades at high temperature. This study analyses whether substituting those linings with 3D-printed concrete (3DPC) can enhance load bearing fire rating (LFR) and insulation fire rating (IFR) under both standard and severe hydrocarbon fire exposures.Design/methodology/approachEighty-eight finite-element models simulated LSF walls combining steel lipped channels and 3DPC facings. Parameters varied were 3DPC thickness (25-100 mm), cavity-insulation type (rockwool or glass fibre) and infill ratio (20-100%). Critical outputs were time to reach steel temperatures of 320 degrees C, 490 degrees C and 640 degrees C (load ratios 0.6, 0.4, 0.2) and time to 160/200 degrees C on the unexposed face.FindingsReplacing 25 mm panels (IFR = 18 min in hydrocarbon fire) with 100 mm 3DPC panels extended insulation fire resistance beyond the 240-min analysis window; under the standard curve, 50 mm panels already sustained the 0.2 load ratio for over four hours. Rockwool increased IFR by up to 55% and added more than 60 min to LFR. Regression models linking thickness, fill, fire severity and insulation type achieved R2 values to 0.992.Originality/valueThis is the first systematic investigation of 3DPC-LSF walls under both rapid-rise hydrocarbon and standard fires. It supplies design-ready regression models and shows that 3DPC walls = 50 mm, especially with rockwool, deliver multi-hour structural and insulation fire resistance, up to 50% higher than plasterboard, making them a viable, fire-robust alternative for fire-safe LSF construction.