In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM’s durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca2+ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.

1. Introduction
2. Experimental Procedure
    2.1. Material of experiment
    2.2. Compaction test and mix proportion
    2.3. Testing method
3. Results and Discussion
    3.1. Unconfined compressive strength
    3.2. Splitting strength
    3.3. Compressive rebound modulus
    3.4. Freeze-thaw cycle
    3.5. EDTA titration method
    3.6. Microstructure analysis of CSM
4. Conclusion
Acknowledgement
References
Author Information

• Qifang Ren(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Fan Bu(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Qinglin Huang(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Haijun Yin(Beijing Rechsand Sand Industry Casting Material Co., Ltd., Beijing 100005, China)
• Yuelei Zhu(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Rui Ma(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Yi Ding(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Libing Zhang(Anhui Road and Bridge Engineering Group Co., Ltd., Hefei 230088, China)
• Jingchun Li(Anhui Road and Bridge Engineering Group Co., Ltd., Hefei 230088, China)
• Lin Ju(Anhui Road and Bridge Engineering Group Co., Ltd., Hefei 230088, China)
• Yanyan Wang(Anhui Institute of Building Research and Design, Hefei 230031, China)
• Wei Xu(Anhui Construction & Building Materials Technology Group Co., Ltd., Hefei 230001, China)
• Haixia Ji(School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China)
• Won-Chun Oh(Department of Advanced Materials Science and Engineering, Hanseo University, Seosan 31962, Republic of Korea) Corresponding author