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<p>The paper focuses on the curing kinetics of Portland cement as a&#xa0;non-equilibrium condensed matter in the temperature gradient of 65&#xa0;to −20 °C. The finite element method is used for 2D modeling of Portland cement curing based on the modified Wang model and the analysis of cement hydration processes and its physical and mechanical properties during a&#xa0;transition from one stage to another (incubation → diffusion → acceleration → retardation). Localized temperature gradients hinder hydration at the cooled (<i>T</i> = −20 °C) end of the cement rod, where phase transitions are not completed in some regions. Exothermic reactions act as distributed heat sources, creating reflected heat flows (analogs of reaction and diffusion processes in disordered systems). It is found that the maximum von Mises stress (up to 2.5 МPа) occurs at the interface between the cement rod and thermal insulation and in regions with <i>T</i> &lt; 0 °C, where superposition of direct and reflected heat flows leads to critical strains. Stresses exceed the elastic strength of the material that corresponds to the crack nucleation theory in condensed matter with inhomogeneous structure.</p>

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Influence of temperature gradient fields on curing stages of Portland cement

  • 期刊论文

  • 发表日期：

    2025年8月1日

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  • Yu. A. Abzaev,
  • A. A. Klopotov,
  • S. V. Korobkov,
  • V. A. Vlasov,
  • V. A. Ushkov,
  • D. A. Zorin,
  • M. G. Bruyako,
  • M. F. Kuzhin

摘要

The paper focuses on the curing kinetics of Portland cement as a non-equilibrium condensed matter in the temperature gradient of 65 to −20 °C. The finite element method is used for 2D modeling of Portland cement curing based on the modified Wang model and the analysis of cement hydration processes and its physical and mechanical properties during a transition from one stage to another (incubation → diffusion → acceleration → retardation). Localized temperature gradients hinder hydration at the cooled (T = −20 °C) end of the cement rod, where phase transitions are not completed in some regions. Exothermic reactions act as distributed heat sources, creating reflected heat flows (analogs of reaction and diffusion processes in disordered systems). It is found that the maximum von Mises stress (up to 2.5 МPа) occurs at the interface between the cement rod and thermal insulation and in regions with T < 0 °C, where superposition of direct and reflected heat flows leads to critical strains. Stresses exceed the elastic strength of the material that corresponds to the crack nucleation theory in condensed matter with inhomogeneous structure.