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BULLETIN OF THE CHINESE CERAMIC SOCIETY ›› 2026, Vol. 45 ›› Issue (6): 2052-2062.DOI: 10.16552/j.cnki.issn1001-1625.2025.1110

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

Hydration and Hardening Mechanism and Property Optimization of SS-GBFS-Cement-DG Quaternary Cementitious System

WU Yankun1,2(), CHEN Jian1,3,4, HAO Jianshuai2(), FANG Kuizhen2   

  1. 1.China Railway 14th Bureau Group Co.,Ltd.,Jinan 250101,China
    2.School of Civil Engineering,Tsinghua University,Beijing 100084,China
    3.CRCC Underwater Tunnel Engineering Laboratory,Jinan 250101,China
    4.College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China
  • Received:2025-11-12 Revised:2025-12-08 Online:2026-06-15 Published:2026-07-16
  • Contact: HAO Jianshuai

Abstract:

To achieve the high-value resource utilization of bulk industrial solid wastes, this study constructed a quaternary cementitious system centered on the synergy between steel slag (SS) and granulated blast furnace slag (GBFS), activated by cement and desulfurization gypsum (DG). The synergistic hydration mechanism of the quaternary cementitious system under composite activation was revealed through systematic mixture proportion design and micro-characterization techniques such as mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The interwoven formation of hydration products ettringite (AFt) and calcium silicate hydrate (C-S-H) gel continuously consumed Ca(OH)2, thereby driving significant pore refinement and microstructural densification, was elucidated. The optimal mass fractions for each key component is 40% GBFS, 10% cement, and 8%~12% DG. Hydration kinetics analysis indicates that the system exhibits typical three-stage exothermic characteristics: aluminate phase reaction, silicate hydration of cement, and a pronounced secondary reaction stage attributable to the alkaline-sulfate activation of GBFS. The sulfate from DG and alkalinity from cement jointly activated the GBFS and SS, promoting continuous formation of AFt and C-S-H gel while extensively consuming Ca(OH)2. MIP and SEM results further demonstrate significant microstructural densification of the quaternary cementitious system at 28 d: the proportion of harmful pores (>50 nm) decreases markedly, while that of harmless gel pores (<50 nm) increases from 68% to 81%. The C-S-H gel develops from an interlaced distribution into a continuous honeycomb-like structure, tightly interwoven with AFt crystals to form a dense network. This research clarifies the underlying strength development mechanism of the quaternary binder system, driven by synergistic activation and pore structure refinement. It offers a theoretical foundation and technical route for the development of high-performance, low-carbon construction materials.

Key words: steel slag, multi-component cementitious system, mechanical property, microstructure, pore structure characteristic

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