A moisture-dependent thermomechanical constitutive model for concrete subjected to transient high temperatures

Research output: Contribution to journalArticle


  • Giacomo Torelli
  • Martin Gillie
  • Parthasarathi Mandal
  • Jefri Draup
  • Van Xuan Tran

External departments

  • University of Sheffield
  • New Model in Technology & Engineering (NMiTE)
  • University of Manchester
  • Électricité de France S.A.


Original languageEnglish
Article number110170
JournalEngineering Structures
Early online date28 Feb 2020
Publication statusPublished - 1 May 2020
Externally publishedYes
Publication type

Research output: Contribution to journalArticle


This paper presents a constitutive model for concrete able to capture the effects of the moisture content of the material on its mechanical behaviour under compressive loads and high transient temperatures. The model is the first to account for the experimentally demonstrated effect of moisture content on the two components of thermal strain, Load Induced Thermal Strain (LITS) and Free Thermal Strain (FTS). Both LITS and FTS are formulated as functions of the water content of the material at the beginning of the thermal transient. First, the theoretical formulation and numerical implementation of the model are presented. Then, the model is verified and validated against published transient tests on concrete specimens having different initial moisture contents. Finally, it is employed to assess a representative nuclear pressure vessel subjected to fault conditions. The results show that the model allows the moisture dependent behaviour of concrete heated under mechanical load to be accurately captured. Furthermore, it is shown the introduction of moisture-dependent thermal strain components is crucial to capture the behaviour of nuclear pressure vessels subjected to fault conditions. If the moisture-dependency of thermal strain of concrete is not considered, non-conservative results may be obtained.