Steel slag for carbon fixation and synthesis of alkali-activated material. (10th October 2022)

• Record Type: Journal Article
• Authors: Sun, Zengqing; Liu, Qingsong; Ma, Shihui; Huang, Xiaoxian; Gan, Min; Ji, Zhiyun; Chen, Xuling; Fan, Xiaohui
• Is Part Of: Construction & building materials. Volume 351(2022)
• Publication Date: 2022-10-10
• Subjects: Steel slag -- Carbon fixation -- Alkali activation -- Reaction mechanism; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.128959
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Alkali-activated material is synthesized using carbonated steel slag. Mix-design dominates the mechanical property of synthesized AAM. Synthesized AAM possesses compact and dense microstructure. CASH is the main reaction product of synthesized AAM. Abstract: In this work, steel slag is utilized for carbon fixation and the obtained carbonated steel slag (CSS) was creatively adopted as solid precursor for the synthesis of alkali-activated materials (AAMs). Physicochemical properties of CSS were fully characterized, influences of mix proportion on strength development of alkali-activated CSS (AACSS) mortar were investigated. To gain insight into the reaction mechanism, special attention is paid on the mineral composition, chemical bond and microstructure of AACSS. Results show that the mechanical properties of AACSS were significantly influenced by mix-design, and the 28 d compressive strength of AACSS mortar ranged from 0.52 MPa to 12.13 MPa. After alkali activation, porous and individual CSS particles were transformed into dense and compact gel-like matrix, with CASH as the main reaction product. Findings from this work contributed to extend the industry chain of steel slag carbon fixation and the sustainable development of cementitious construction materials.