A binder prepared by low-reactivity blast furnace slags for cemented paste backfill: Influence of super-fine fly ash and chemical additives. (11th April 2022)

• Record Type: Journal Article
• Authors: Zhao, Zhiyun; Guo, Kaihua; Wang, Xiangling
• Is Part Of: Construction & building materials. Volume 327(2022)
• Publication Date: 2022-04-11
• Subjects: Cemented paste backfill -- Low-carbon binders -- Reaction kinetics -- Compressive strength -- Superfine fly ash; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.126988
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: SFA, AlS and CC were used to modify the properties of binder for CPB. The hydration mechanism of the binder was found to be 'NG-I-D'. Enhanced property was due to refined pore structure and increased reaction gels. Excess AlS delayed binder hydration. Abstract: Alternative binders for cemented paste backfill (CPB) are necessary to be prepared considering the high cost and environmental footprint of ordinary Portland cement (OPC). This study focuses on the preparation of a binder using low-reactivity blast furnace slag (BFS). Superfine fly ash (SFA) and chemical additives (aluminum sulfate, AlS and carbide slag, CC) are used to modify the binder properties. Both SFA and chemical additives could promote the binder reaction with the formation of more reaction products. The pore structure was then refined; thereby higher compressive strength was observed. Krstulovic-Dabic (K-D) model was used to characterize the hydration process and all binders hydration mechanism was 'NG-I-D'. The synergistic effect of SFA, AlS, and CC showed the best performance, the compressive strength of the CPB samples could reach 0.24 MPa and 2.73 MPa at 3 and 28 days using the optimal proportion. The excellent performance can be attributed to the physical and chemical effects of the coupling actions of SFA and chemical additives.