Full-scale fire experiments on load-bearing cold-formed steel walls lined with different panels

Cold-formed steel (CFS) wall systems were increasingly used as primary load-bearing structural components in residential and industrial buildings. Previous studies were mainly to investigate the fire performance of non-load bearing CFS wall systems lined with gypsum plasterboards. In order to improve the fire performance of load-bearing CFS wall systems more efficiently, this paper presented a detailed experimental investigation on five full-scale CFS walls lined with double layers of three different fire resistant panels on both sides, including fire-resistant gypsum plasterboard, bolivian magnesium board and calcium silicate board. The results showed a noticeable disadvantage of the calcium silicate board due to explosive spalling at high temperatures, and this might cause severe safety issues in an actual fire situation. For CFS walls lined with gypsum plasterboard as the face layer and bolivian magnesium board as the base layer on both sides, different load ratios may result in different failure modes, and the fire resistance time would be more than 90 min when the load ratio was less than 0.65. It was also demonstrated that the fire performance of bolivian magnesium board was superior to that of the fire resistant gypsum plasterboard, therefore the former may be recommended to be used in CFS structures to replace gypsum plasterboards as the base layer.