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Lecture

WEB A phase-field model for autogenous self-healing of cracks in concrete




Concrete structures are affected by various environmental factors, such as changes in temperature and

humidity, external loads, etc., which cause micro-cracks or damage of different shapes and sizes. This

greatly reduces the durability of concretes [1]. The autogenous self-healing mechanism is one of the

methods to effectively extend the lifespan of concretes. This work aims to investigate the autogenous

self-healing process of small cracks with a width of less than 0.2 mm [2] in concrete using the numerical

method. Autogenous self-healing is consist of the calcium hydroxide dissolution and the precipitation

reaction of calcium carbonate. A phase-field model is developed by incorporating the chemical reaction

kinetics, diffusion and thermodynamics, and numerically implemented by the finite element method

(FEM) within the MOOSE framework [3]. In order to investigate the evolution of the chemistry of the

system, a 1D reaction-diffusion model is employed by means of geochemistry PHREEQC calculation

code [4]. In this model, the carbon dioxide is added to water at a logarithmic partial pressure of -3.4 in

order to model a situation with unlimited supply of calcium hydroxide to the water phase. The simulation

results in PHREEQC was used to feed parameters of the phase-field model. We further investigate the

microscopic crack morphology by performing multiple simulations with the parameter informed from

the experimental tests.


 

Speaker:
Sha Yang
Technische Universität Darmstadt
Additional Authors:
  • Yangyiwei Yang
    Technische Universität Darmstadt
  • Dr. Neven Ukrainczyk
    Technische Universität Darmstadt
  • Dr. Antonio Caggiano
    Technische Universität Darmstadt
  • Prof. Dr. Eddie A.B. Koenders
    Technische Universität Darmstadt