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BULLETIN OF THE CHINESE CERAMIC SOCIETY ›› 2023, Vol. 42 ›› Issue (4): 1333-1343.

Special Issue: 资源综合利用

• Solid Waste and Eco-Materials • Previous Articles     Next Articles

Interaction Mechanism of Carbide Slag Activating Slag-Fly Ash Composite Cementitious Materials

AN Sai1,2, WANG Baomin1, CHEN Wenxiu3, ZHAO Qingxin4   

  1. 1. Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, China;
    2. College of Urban Construction, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China;
    3. Qinhuangdao Quality and Technology Supervision and Inspection Institute, Qinhuangdao 066004, China;
    4. Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province, Qinhuangdao 066004, China
  • Received:2023-01-05 Revised:2023-02-08 Online:2023-04-15 Published:2023-04-25

Abstract: In order to study the resource utilization of slag, fly ash and carbide slag, the hydration product composition and strength characteristics of slag-fly ash composite cementitious materials were studied with carbide slag as alkali activator. The crystal structure, thermochemical properties and microscopic morphology of the composite cementitious materials were analyzed by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric-differential scanning calorimetry (TG-DSC), scanning electronic microscopy-energy dispersive spectroscopy (SEM-EDS), and the interaction mechanism of carbide slag activating slag-fly ash composite cementitious materials was studied. The results show that carbide slag as alkali activator provides a strong alkaline environment for the initial hydration of slag-fly ash composite cementitious materials, and it can also drive the hydration reaction of slag and fly ash. With the increase of slag content, the strength of composite cementitious materials increases first and then decreases. When the mass proportion of fly ash and slag is 4∶6, and the mass addition of carbide slag is 4%, the compressive strength of composite slurry reaches 25.9 MPa under the conditions of 4 d normal temperature curing and 32 h high temperature steam curing. The hydration products of the slag-fly ash composite cementitious system are unevenly distributed, containing C-S-H, C-A-H, C-A-S-H gel and etc. Carbide slag has a good effect as alkali activator in slag-fly ash system.

Key words: carbide slag, slag, fly ash, alkali excitation, cementitious material, micro composition, interaction mechanism

CLC Number: