A multi-physics modelling based on coupled diffusion equations to simulate the carbonation process

abstract: Carbonation is widely recognized as a cause of significant pathologies in reinforced concrete structures and different modelling strategies are presented in literature the simulate the phenomenon evolution. In opposition to the deleterious effect in reinforced concrete, for historical mortar made with aerial lime, the carbonation is essential for the hardening process. For both materials, carbonation process presents similarities. This work presents the background/implementation of an algorithm for a multi-physics simulation of the main fields associated with the carbonation process. This modelling was previously validated in literature. A 1D algorithm is implemented, using the Finite Difference Method. Its feasibility is demonstrated through the simulation of results presented in the literature. A parametric study is also shown considering the main parameters involved, important observation regarding the influence of the parameters on the carbonation depth are detailed.

摘要：碳化作用（Carbonation）已被广泛认定为引发钢筋混凝土结构产生严重病害的关键诱因，现有文献已提出多种建模策略以模拟该现象的演化进程。与在钢筋混凝土中产生的有害影响不同，以气硬性石灰制备的历史砂浆，其硬化过程却离不开碳化作用。两类材料的碳化过程具有共通特征。本研究详细阐述了用于模拟碳化过程相关多物理场的算法的背景与实现方案，该建模方法已在既往研究中得到验证。本次研究采用有限差分法（Finite Difference Method）构建了一维算法，通过复现文献中已发表的仿真结果，验证了该算法的可行性。本研究还开展了参数化分析，考量了核心影响参数，并详细阐述了各参数对碳化深度的影响这一重要研究结论。