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谭小蓉

 

(西安铁路职业技术学院 , 西安   710600)

摘  要: 为研究铁尾矿砂  (IOT) 取代率对铁尾矿砂水泥基复合材料  (IOTCC) 力学性能与耐久性能的影响 , 采用强度试验 、抗氯离子侵蚀试验和碳化深度测试评价其宏观性能 , 并结合核磁共振  (NMR) 和扫描电子显微镜  (SEM) 分析其孔结构与微观形貌 , 揭示碳化作用下材料性能演化机制 。结果表明 : IOT 可作为 IOTCC的细骨料 , 在 25% ~75%取代率范围内均有助于改善材料力学性能 , 其中25%取代率时综合力学性能 、抗氯离子侵蚀性能和抗碳化性能最优 , 且孔隙率最低 。随着碳化时间延长 , IOTCC 孔隙率呈前期快速降低 、后期缓慢下降的变化规律 。综上 , 25%的 IOT 取代率为本研究条件下 IOTCC 细骨料替代的推荐掺量 , 其性能改善主要归因于 IOT 的微填充效应及由此带来的孔结构致密化 。研究成果可为相关工程提供参考。

关键词: 铁尾矿砂 ; 水泥基 ; 力学性能 ; 耐久性 ; 微观特征

中图分类号: TU528. 09      文献标志码: A      文章编号: 1005-8249 (2026) 04-0025-07

DOI:10. 19860/j. cnki. issn1005-8249. 2026. 04. 004

 

Experimental Study on the Mechanical Properties and Durability of

Iron Tailings-Based Cementitious Composites

TAN Xiaorong

(Xi ’an Railway Vocational and Technical Institute, Xi ’an 710600, China )

Abstract : To investigate the effects of iron ore tailings sand (IOT) replacement ratio on the mechanical properties and durability of iron ore tailings cementitious composites (IOTCC) , compressive strength tests, chloride ion penetration resistance tests, and carbonation depth tests were conducted to evaluate their macroscopic performance.  In addition, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) were employed to characterize the pore structure and micro-morphology of IOTCC, thereby revealing the performance evolution mechanism under carbonation. The results show that IOT can be used as a fine aggregate in IOTCC. Within the replacement ratio range of 25% to 75% , IOT contributes to the improvement of the mechanical properties of the composites. Among them, the specimen with a 25% replacement ratio exhibits the best overall mechanical performance, chloride ion penetration resistance, and carbonation resistance, as well as the lowest porosity.  With increasing carbonation age, the porosity of IOTCC decreases rapidly at the initial stage and then declines gradually at later stages. This behavior is mainly attributed to the filling effect of carbonation product CaCO3 on the pores and its inhibition of further CO2 diffusion. Overall, a 25% IOT replacement ratio is recommended for fine aggregate substitution in IOTCC under the conditions of this study, and the performance enhancement is mainly associated with the micro-filling effect of IOT and the resulting densification of the pore structure. The research findings can provide reference for relevant engineering projects.

Key words: iron tailing sand; cementitious; mechanical properties; durability; microscopic characteristics