Zhaohui Huang
Brunel University London, UK
Title: Modelling Reinforced Concrete Structures under Fire Conditions
Biography
Biography: Zhaohui Huang
Abstract
In recent years, a robust finite-element software Vulcan has been developed for three-dimensional modelling of reinforced concrete structures under fire conditions. In this non-linear procedure a reinforced concrete building is modelled as an assembly of finite plain beam–column and slab elements, reinforcing steel bar elements and bond-link elements. Both material and geometric non-linearities are considered in the model. To consider the effects of concrete spalling on the thermal and structural behaviours of concrete structures in fire, a ‘void layer’ and ‘void segment’ are introduced to represent the spalled concrete part within concrete slabs, beams and columns. A critical temperature is used as the concrete spalling criterion. These developments enable the model to simulate quantitatively the effects of concrete spalling on both the thermal and structural behaviours of reinforced concrete structures in fire. Under fire conditions, the formation of large cracks within reinforced concrete floor slabs may significantly reduce the fire resistance of buildings. For modelling integrity failure of reinforced concrete slabs in fire, a nonlinear hybrid FE model has been developed to predict the large cracks formed in RC floor slabs. The developed model was validated using the previous tested results. The nonlinear model developed can be used for assessing the integrity failure of the floor slabs in fire. Also a robust finite element procedure for modelling the localised fracture of reinforced concrete beams at elevated temperatures has been developed. An extended finite element method (XFEM) has been incorporated into the concrete elements in order to capture the localised cracks within the reinforced concrete beams