Finite element analysis of coupled heat and mass transfer in concrete when it is in a fire

Abstract

This paper presents a comprehensive model for simulating coupled heat and mass transfer in concrete when it is subjected to a fire. The model considers not only the transport of dry air, water vapour and liquid water but also the evaporation of liquid water and the dehydration of bound water. It can be applied to multidimensional problems. The governing equations describing this coupled heat and mass transfer phenomenon are solved using finite element methods with a standard Galerkin approximation. Results related to temperature, pore pressure, moisture content, the level of evaporation and dehydration of water within concrete for a standard fire curve are given. The influence of the liquid water transport on the spatial distributions of temperature and pore pressure is investigated through the use of parametric studies. The present results can be used to predict the potential of concrete spalling.

Numerical modeling of supercritical carbonation process in cement-based materials

“…Thus, the enthalpy balance equation of the entire medium, including the convectional and latent heat transfer, is given by (see, for example [31][32][33]). …”

Nonlinear analysis of orthotropic composite slabs in fire

“…The higher temperatures at the thin parts of the slab (see Line 2 of Fig. 1) are defined at six Gauss integration points (1,2,3,7,8,9), and the cooler temperatures at the thick part (see Line 1 of Fig. 1) are assigned to three Gauss integration points (4,5,6).…”

“…The water phase (bound, liquid or gaseous), the dimensions of the structure, the mixture type, concrete porosity and the heating history all affect the temperatures in the slab [2,3]. An added complexity comes from the coupled thermo-hydral-mechanical processes in the heated concrete.…”

An application of a damage constitutive model to concrete at high temperature and prediction of spalling

“…(38)-(41) a system of three differential equations remains which is solved for T, P G , andq V . A full description of the model and its finite element discretisation is given by Tenchev et al (2001a) and some variations in Tenchev et al (2001b), Tenchev et al (2001c), Li et al (2002).…”