文献类型： 外文期刊

第一作者： Mehdizadeh, Hamideh

作者： Mehdizadeh, Hamideh;Ma, Mengting;Ling, Tung-Chai;Ling, Tung-Chai;Mehdizadeh, Hamideh

作者机构：

关键词： Aqueous carbonation; Basic oxygen furnace slag (BOFS); Cement paste; C -S-H morphology; Carbonated solution

期刊名称：JOURNAL OF BUILDING ENGINEERING （ 影响因子：7.4； 五年影响因子：7.5 ）

ISSN：

年卷期： 2024 年 98 卷

页码：

收录情况： SCI

摘要： Aqueous carbonation (AC) treatment is a promising method for enhancing the cementitious activity of Ca- and Mg-rich solid wastes, such as basic oxygen furnace slag (BOFS), while also reducing carbon emissions. However, the carbonated filtrate (CF) solution generated during the AC process poses significant environmental challenges and limits its large-scale application. This paper, therefore, explores the feasibility of recycling CF in cement paste production as a strategy for managing AC wastewater. The study examines the impact of CF on the physico-mechanical properties, hydration behavior and microstructure of cement pastes (pure and blended with either 10% as-received or carbonated BOFS), compared to those prepared with tap water (TW) and carbonated water (CW). The results indicate that carbonated solutions (CF and CW) promote the hydration of aluminate phase in cement, with a more pronounced effect observed for CW. The solid suspensions in CF, particularly nesquehonite, restrict the growth space for calcium silicate hydrates (C-S-H) in the paste matrix, resulting in the formation of foil-like Type II C-S-H and lowering compressive strength. However, the additional nucleation sites provided by calcite crystals in carbonated BOFS (C-BOFS) accelerate cement hydration in CF-based pastes and mitigate strength loss by promoting the formation of more fibrillary C-S-H. Furthermore, the addition of a superplasticizer reduces interparticle forces in the C-BOFS-CF paste, further enhancing strength development and achieving a 28-day strength comparable to that of the control sample (OPC-TW paste).

分类号：