Title: Modeling Two-Dimensional Coupled Heat and Mass Transfer Phenomena in Fire-Exposed Concrete

Author(s): Manar A. Al Fadul and Kevin R. Mackie

Publication: Materials Journal

Volume: 117

Issue: 6

Appears on pages(s): 29-42

Keywords: control volume; dehydration; evaporation; finite difference; fire

DOI: 10.14359/51728122

Date: 11/1/2020

Abstract:
A model that simulates the two-dimensional (2-D) coupled heat and mass transfer phenomena in heated concrete is proposed. A fully implicit finite difference (FD) method was used in the discretization of the partial differential equations in both domain and time. The control volume approach was employed in the formulation of the FD equations, ensuring both local and global conservation properties are satisfied by the numerical solution. The solid, liquid, and gaseous (both air and vapor) phases are considered, including evaporation, condensation, and dehydration. The discretized equations of all species along with the temporal discretization of an interior node, surface node, and corner node are presented. Numerical case studies based on an object-oriented code for extremely rapid heating of concrete and nonsymmetric boundary conditions are validated against experimental results. Temperature, pressure, and moisture contours indicate the model’s ability to capture the complex 2-D behaviors of fire-exposed concrete over the entire flow domain.