混凝土结构孔隙侵蚀数值模拟

Numerical simulation of pore erosion in concrete structure

混凝土材料所具有的多孔隙结构是由其本身的物理、化学性质所决定的,而孔隙结构又决定了混凝土整体的强度和渗透性。将混凝土复杂的孔隙结构简化为单根毛细管,根据Fick定律和质量守恒原理推导出混凝土孔隙溶解控制方程,并运用Bear理论中关于多孔介质毛细孔渗透率的研究理论及饱和溶质运移扩散方程建立侵蚀模型。模拟结果表明,该模型能够有效地反映混凝土孔隙中固相钙离子溶解、浓度变化和孔隙边壁侵蚀厚度变化过程。

The concrete material has a porous structure due to its own physical and chemical properties, and the pore structure determines the strength and permeability of concrete. In this paper, the complex porous structure of concrete was simplified to the single capillary. According to the Fick＇s law and mass conservation principle, the dissolution equation of concrete pores was obtained, and the erosion model was established based on the research of capillary permeability of porous medium in Bear theory and saturated solute transport diffusion equations. The simulation results showed that the model can reflect the variations of dissolution and concentration of solid phase calcium ions and erosion thickness of side wall in pores.