基于自然浸泡法的锂渣混凝土对氯离子吸附性能研究

Study on Chloride Ion Adsorption Performance of Lithium Slag Concrete Based on Natural Immersion Method

摘要: 一般认为混凝土结构的水下部分由于长期浸泡使混凝土内部孔隙水饱和。因此，本文针对自然浸泡环境下的混凝土试块，进行了其对氯离子吸附能力的研究。本研究探讨了锂渣掺量、抗压强度、氯盐浓度、侵蚀时间和扩散深度对锂渣混凝土的氯离子吸附性能的影响。结果显示，随着锂渣掺量的提高，不同强度的锂渣混凝土对Cl⁻的吸附能力呈现随机性。但是当锂渣掺量为30%时，低强度锂渣混凝土的吸附能力较好。随着锂渣混凝土强度等级的增大，不同掺量的锂渣掺量混凝土对Cl⁻的吸附能力总体呈下降趋势。随着Cl⁻浓度的增加，不同强度的锂渣混凝土的Cl⁻的吸附能力呈现基本相同的趋势。随着侵蚀时间的增加，锂渣混凝土的Cl⁻的吸附能力先急剧减小，然后趋于平缓。说明锂渣混凝土的早期对氯离子的吸附能力较强，随着试验时间的增长，其吸附能力变弱。随着扩散深度的增加，不同NaCl溶液浓度的Cl⁻的吸附能力的变化趋势有所不同。浸泡于浓度较低的5%和10%的锂渣混凝土对Cl⁻的吸附能力随着锂渣掺量的增加的增多。而浓度较高的20%的锂渣混凝土对Cl⁻的吸附能力与强度有关。基于上述实验结果，本研究对处于自然浸泡环境下锂渣混凝土在工程应用过程中提供了一定的参考意义。

Abstract: It is generally believed that the underwater part of the concrete structure can be saturated with pore water due to long-term immersion. Therefore, the adsorption capacity of chloride ions on concrete samples soaked in natural environment was studied in this paper. The effects of lithium slag content, compressive strength, chloride salt concentration, erosion time and diffusion depth on chloride ion adsorption performance of lithium slag concrete were studied. The results showed that the adsorption capacity of Cl⁻ for lithium slag concrete with different strength was acted of indiscipline with the increase of lithium slag content. However, the adsorption capacity of low strength lithium slag concrete was better when the lithium slag content was 30%. With the increase of strength grade of lithium slag concrete, the adsorption capacity of Cl⁻ to concrete with different lithium slag content was generally decreased. Meanwhile, the adsorption capacity of Cl⁻ of lithium slag concrete with different strength showed basically the same trend with the increase of Cl⁻ concentration. With the increase of erosion time, the adsorption capacity of Cl⁻ in lithium slag concrete decreased sharply first and then tended to be gentle, showing that the adsorption capacity of chloride ion in the early stage of lithium slag concrete was strong. But with the increase of test time, its adsorption capacity became weak. With the increase of diffusion depth, the adsorption capacity of Cl⁻ with different concentrations of NaCl solution was different. It was obtained that the adsorption capacity of Cl⁻ to concrete soaked in 5% and 10% lithium slag with lower concentration was increased with the increase of lithium slag content but the adsorption capacity of Cl⁻ for 20% lithium slag concrete with higher concentration was related to its strength. Based on the above experimental results, this study could provide some reference for the application of lithium slag concrete in the natural immersion environment.