Chen Lijun, Zhao Gang, Li Ying
School of Civil Engineering and Water Resources, Qinghai University, Xining 810016, China.
Key Laboratory of Material and Engineering Safety for Building Energy Conservation in Qinghai Province, Xining 810016, China.
Materials (Basel). 2025 Apr 29;18(9):2018. doi: 10.3390/ma18092018.
The Qinghai-Tibet Plateau features a high-altitude, cold, and arid climate, with harsh environmental conditions. It is also one of the regions in China where chloride-rich salt lakes are abundant. These circumstances pose significant challenges to the durability of concrete. This study explored the impact of recycled fine powders (RFP) on the resistance of concrete to chloride ion erosion. To evaluate this, a 3.5% sodium chloride solution and Qarhan Salt Lake brine were employed as erosion media. The depth and concentration of chloride ion penetration, the free chloride ion diffusion coefficient (D), and the microstructure of the concrete were measured. The results demonstrated that when the replacement rate of RFP was 20%, the concrete displayed excellent resistance to chloride ion erosion in both the sodium chloride solution and the Salt Lake brine. XRD analysis and SEM images revealed that the addition of RFP enabled the concrete to bind more Cl to form Friedel's salt, which filled the pores of the concrete and reduced the diffusion of Cl within the concrete. Moreover, as the soaking time extended continuously, the erosion and damage effects of the Salt Lake brine solution on the concrete were more severe than those of the sodium chloride solution.
青藏高原气候高寒干旱，环境条件恶劣。它也是中国富氯盐湖分布较多的地区之一。这些情况给混凝土的耐久性带来了重大挑战。本研究探讨了再生细粉（RFP）对混凝土抗氯离子侵蚀性能的影响。为此，采用3.5%的氯化钠溶液和察尔汗盐湖卤水作为侵蚀介质。测量了氯离子渗透的深度和浓度、自由氯离子扩散系数（D）以及混凝土的微观结构。结果表明，当RFP的取代率为20%时，混凝土在氯化钠溶液和盐湖卤水中均表现出优异的抗氯离子侵蚀性能。XRD分析和SEM图像显示，RFP的加入使混凝土能够结合更多的Cl形成Friedel盐，填充了混凝土的孔隙，减少了Cl在混凝土内部的扩散。此外，随着浸泡时间的不断延长，盐湖卤水对混凝土的侵蚀破坏作用比氯化钠溶液更为严重。
