| 摘要: |
| 针对材料制备与环境服役过程中水泥基材料的性能演变问题,开展了水泥净浆薄片养护溶蚀全过程中主要物相及微结构演变的定量分析.首先,根据水泥的矿物组成及其水化机理,建立了水泥水化反应的简化模型及其主要水化产物浓度的计算方法;其次,利用Fick定律及质量守恒定律,建立了溶蚀条件下水泥净浆孔溶液中主要离子(K+、Na+、OH-及Ca2+)的传输模型;最后,与已有试验结果对比分析验证了模型的合理性,在此基础上,数值模拟了水泥净浆薄片试件养护溶蚀全过程.结果表明：所建立的模型可定量分析养护溶蚀全过程中水泥净浆孔溶液中主要离子浓度、孔隙率分布及氢氧化钙（CH）、水化硅酸钙（C S H）凝胶浓度的变化规律,且可用于软水环境下水泥基材料抗溶蚀性能的定量设计. |
| 关键词: 水泥净浆 软水溶蚀 水泥水化 离子扩散 数值模拟 |
| DOI：103969/j.issn.1007 9629202005003 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51778297) |
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| Numerical Simulation on Entire Process of Curing and Leaching of Cement Paste |
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LI Xiangnan, ZUO Xiaobao, CUI Dong, YIN Guangji, TANG Yujuan
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Department of Civil Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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| Abstract: |
| In order to investigate the performance evolution of cement based materials from curing to in serviced utilization, a quantitative analysis was performed on the main phase and microstructure evolution of cement paste in the entire process of curing and leaching. Firstly, based on the mineral composition of cement and its hydration mechanism, a simplified model of cement hydration was presented to calculate the concentration of its main products. Secondly, by using Ficks law and the conservation law of mass, the diffusion model of main ions, such as K+, Na+, OH- and Ca2+, in the pore solution of cement paste in soft water was established. Finally, the model was verified via its calculated data and the experimental results in the present literature. On the basis of the above model, numerical analysis was performed to investigate the entire process of curing and leaching of cement paste slice specimen. Results show that the models can quantitatively analyze the ionic concentration in the pore solution, porosity distribution, calcium hydroxide(CH) and calcium silicate hydrate(C S H) gel contents in the entire process, and it can be useful for the quantitative design on the leaching resistance of cement based materials in soft water environments. |
| Key words: cement paste soft water leaching cement hydration ion diffusion numerical simulation |
