Numerical modelling of non-load-bearing light gauge cold-formed steel frame walls under fire conditions

Recently an innovative composite panel system was developed, where a thin insulation layer was used externally between two plasterboards to improve the fire performance of light gauge cold-formed steel frame walls. In this research, finite-element thermal models of both the traditional light gauge cold-formed steel frame wall panels with cavity insulation and the new light gauge cold-formed steel frame composite wall panels were developed to simulate their thermal behaviour under standard and realistic fire conditions. Suitable apparent thermal properties of gypsum plasterboard, insulation materials and steel were proposed and used. The developed models were then validated by comparing their results with available fire test results. This article presents the details of the developed finite-element models of small-scale non-load-bearing light gauge cold-formed steel frame wall panels and the results of the thermal analysis. It has been shown that accurate finite-element models can be used to simulate the thermal behaviour of small-scale light gauge cold-formed steel frame walls with varying configurations of insulations and plasterboards. The numerical results show that the use of cavity insulation was detrimental to the fire rating of light gauge cold-formed steel frame walls, while the use of external insulation offered superior thermal protection to them. The effects of real fire conditions are also presented

Review on Fire Performance of Cellular Lightweight Concrete

Structural fire damage can be identified as a common accidental disaster throughout the world which cause thousands of deaths, injuries and millions in property damage each year. Fire represents one of the most severe conditions to which structures may be subjected. Generally, structural elements will be exposed to very high temperature (1200 ℃) during a fire propagation. Fire safety of a structure is measured in terms of fire resistance, which is the duration that a structural member can exhibit resistance with respect to structural integrity, stability and heat transmission. Concrete generally provides better fire resisting characteristics compared to the other construction materials due to its low thermal conductivity, high heat capacity and slower strength degradation with temperature. Cellular lightweight concrete (CLC) is one of the novel type of concrete which can be identified as a better construction material than conventional concrete due to its numerous advantages. However, limited research work has been carried out to determine the fire performance of CLC. Fire response of structural members depends on the thermal, mechanical and deformation properties of the structural material at elevated temperatures. Even though properties at elevated temperatures for normal weight concrete is available in literature, properties of CLC at elevated temperatures (ambient to 1200 ℃) is not thoroughly investigated. Further, CLC fire rating under natural/parametric fire situations and under hydrocarbon fire situations needs to be studied. EN 1992.1.2 provides minimum thickness requirements under standard fire situations for non-loadbearing and load bearing normal weight concrete walls, but for CLC, these values are not available, hence required to be included. Also, parameters and material property limitations related to spalling effect of CLC during fire exposure has not being investigated. Moreover, residual characteristics of CLC walls after fire situations and ability to withstand a second fire situation needs to be assessed