Abstract Water migration in the gel pore of the calcium silicate hydrate (C-S-H) influences the durability of cement-based material. The water transport in nanoscale gel pore is dramatically different from transport in capillary pore that is governed by the Lucas-Washburn (L-W) function. Coarse grained molecular dynamics (CGMD) is first utilized to model the capillary transport process of water in the 8 nm channel of C-S-H gel. A new capillary transport model is proposed by modifying the classic L-W function, taking into consideration the effects of dynamic contact angle and inertia force, slip length next to interior walls of gel pore and viscosity variation for liquid ultra-confined in nanopores. Theoretical modification reaches reasonable agreement with CGMD results. The effect of pore size on capillary transport is then simulated to confirm the model's transferability. The new model is helpful to understand the transport behavior of liquid in the gel pore of cement-based material.

中文翻译：

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硅酸钙水合物凝胶孔中毛细管输运的修正 Lucas-Washburn 函数：粗粒分子动力学研究

摘要 水化硅酸钙（CSH）凝胶孔隙中的水迁移影响水泥基材料的耐久性。纳米级凝胶孔中的水传输与由 Lucas-Washburn (LW) 函数控制的毛细孔中的传输显着不同。粗粒分子动力学 (CGMD) 首先被用来模拟水在 CSH 凝胶的 8 nm 通道中的毛细管传输过程。通过修改经典的 LW 函数，提出了一种新的毛细管输运模型，同时考虑了动态接触角和惯性力、凝胶孔内壁附近的滑移长度以及纳米孔中超受限液体的粘度变化的影响。理论修正与CGMD结果达到合理一致。然后模拟孔径对毛细管传输的影响以确认模型的可转移性。新模型有助于理解液体在水泥基材料凝胶孔隙中的输运行为。