Comparison of Analytical and Numerical Results for the Charring Rate of the Timber-Concrete Beam

Abstract

Modelling the thermal response of timber is a primary issue for the assessment of the mechanical resistance of timber structures exposed to fire. Therefore, this paper analyses various advanced calculation methods of determining the charring rate. Authors of this contribution use analytical calculation methods according to two different publications and also a numerical calculation by means of program based on Finite Element Method (FEM). Input values of parameters in these calculations were derived from an experiment on a timber-concrete beam, which was realised by two authors of this paper in the past. In conclusion, the values of one-dimensional charring rate of timber calculated by different methods are compared. It is necessary to pay attention to the fact that the resultant values can significantly differ depending on various input values in the analytical calculations. The charring rate increases until a certain time at the beginning of the charring and then it starts to slightly decrease. However, not all of the calculation methods presented in this paper correspond with that.