硅酸盐学报

镁渣对超硫酸盐水泥水化与抗碳化性能的影响

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李想 ¹ , 王栋民 ¹ , 王吉祥 ¹ , 段开瑞 ¹ , 房奎圳 ²

硅酸盐学报 | 低碳水泥与固废资源化利用专题—研究论文 2026,54(5): 1512-1523

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硅酸盐学报 |低碳水泥与固废资源化利用专题—研究论文 2026 , 54 (5) : 1512 -1523

镁渣对超硫酸盐水泥水化与抗碳化性能的影响

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李想¹, 王栋民¹, 王吉祥¹, 段开瑞¹, 房奎圳²

作者信息

^1．中国矿业大学（北京）化学与环境工程学院，北京 100083

^2．清华大学土木工程学院，北京 100084

通讯作者:

王栋民（1965—），男，博士，教授。

王吉祥（1994—），男，博士。

作者简介:

李想（1999—），男，硕士研究生。

Effects of Magnesium Slag on Hydration and Carbonization Resistance of Supersulfate Cement

Xiang LI¹, Dongmin WANG¹, Jixiang WANG¹, Kairui DUAN¹, Kuizhen FANG²

Affiliations

^1.School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China

^2.Department of Civil Engineering, Tsinghua University, Beijing 100084, China

Corresponding Author:

WANG Dongmin (1965-), male, Ph.D., Professor. E-mail: wangdongmin@cumtb.edu.cn

WANG Jixiang (1994—), male, Ph.D. E-mail: wjxiang121@gmail.com

LI Xiang (1999-), male, Master candidate. E-mail: lixiangqlmzls@163.com

出版时间: 2025-08-04 doi: 10.14062/j.issn.0454-5648.20250105

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摘要

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超硫酸盐水泥（SSC）因自身碱度较低而易受CO₂侵蚀。为此，探究了2种富含硅酸钙的镁渣（MS）-MSⅠ（β-C₂S高占比）和MSⅡ（γ-C₂S高占比）对SSC反应速率（凝结时间和反应热）和抗碳化（3%和20% CO₂，体积分数）性能的影响。结果表明，在SSC中掺入富含β-C₂S的MSⅠ延缓了SSC的反应速率、降低了净浆强度，并显著增加了样品在2种碳化浓度下的碳化深度；而富含γ-C₂S的MSⅡ并未影响SSC的反应速率，并降低了碳化深度（20% MSⅡ）；碳化后，掺入MSⅠ和MSⅡ样品的强度均得到了不同程度的提升，后者更为显著。分析认为，尽管MS中硅酸钙自身的碳化增强了掺镁渣SSC在不同碳化龄期下的抗压强度，但相比MSⅡ，X射线衍射与热重结果均表明，MSⅠ中含有的具有水硬性的β-C₂S及少量的Ca（OH）₂抑制了碳化前SSC中石膏的溶解和水化产物的生成，导致了对SSC反应速率、抗压强度和碳化深度的负面影响。因而，就抗压强度和碳化深度而言，掺入含低水硬性硅酸钙的MSⅡ更有利于在不影响SSC自身反应速率的前提下，提升SSC对碳化环境的耐受性。

关键词

硅酸钙 / 镁渣 / 超硫酸盐水泥 / 水化 / 抗碳化性能

Abstract

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Introduction

The low alkalinity makes super-sulfate cement (SSC) vulnerable to being carbonated by CO₂. In this paper, we investigated two magnesium slags, i.e., MSⅠ (the proportion of β-C₂S is higher) and MSⅡ (the proportion of γ-C₂S is higher), and analyzed the impact of CO₂ concentration (i.e., 3% and 20%, in volume) on the SSC from the perspectives of hydration and carbonation. The results show that the addition of MSⅠ (with the higher proportion of β-C₂S) to SSC has a negative impact on the hydration and carbonation resistance due to β-C₂S with a stronger hydration activity, suppressing the hydration of SSC itself and lowering the hydration degree of SSC, reducing the amount of hydrates and further deteriorating the strength and structure development of SSC. The addition of MSⅡ (with the higher proportion of γ-C₂S) has the hydration reaction, and maintains the relative content of hydrates after carbonation and compressive strength increase. This is due to the fact that γ-C₂S significantly enhances the carbonization resistance of SSC.

Methods

The binder consisted of blast furnace slag (BFS), desulfurization gypsum (DGP), red mud (RM), magnesium slag (MSⅠ (with the higher proportion of β-C₂S) and MSⅡ (with the higher proportion of γ-C₂S), and calcium hydroxide. The BFS substitution levels (i.e., 10% and 20%) by MSⅠ and MSⅡ magnesium slag were investigated. The mineral compositions of used magnesium slags were analyzed by X-ray diffraction (XRD). The prepared pastes were cast in the cubic molds with dimensions of 40 mm × 40 mm × 40 mm. After de-molding, the hardened samples were sealed and cured at 25 ℃. After being cured for 28 d, the carbonation test was conducted at different CO₂ concentrations (i.e., 3% and 20%) and a relative humidity of 70%. At the carbonation age of 7, 14 d, and 28 d, the compressive strength, phase composition, and carbonation depth of SCC with and without carbonation were determined by strength test, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and phenolphthalein color test. The microscopic morphologies of SSC before and after carbonation were also analyzed by scanning electron microscopy (SEM). Besides, the early-hydration performance of fresh SSC pastes with MSⅠ and MSⅡ was evaluated via setting time and isothermal calorimetry tests.

Results and discussion

In the hydration stage, the MSⅠ significantly inhibits the hydration rate of SSC. The MSⅠadversely affects the setting time and delays the reaction of SSC. This is because β-C₂S can inhibit the hydration of BFS and reduce the hydration degree of SSC, leading to reduced compressive strength, amounts of hydrates (i.e., ettringite and Calcium aluminum silicate hydrates), and increased carbonation depth after carbonation. The porous and loose microstructures via the SEM images also validate an adverse effect due to the MSⅠ (with the higher proportion of β-C₂S). Also, the addition of MSⅡ does not disrupt the hydration process of SSC and ensure the integrity of hydration phase matrix structure. Meanwhile, a high carbonization activity allows it to react with CO₂ to generate more CaCO₃ and a dense matrix structure, which enhances the carbonation resistance and compressive strength of SSC.

Conclusions

Different types of magnesium slag had different effects on the setting time, reaction rate, and amounts of SSC hydrates. Specifically, the MSⅠ with a higher proportion of β-C₂S and a small amount of Ca(OH)₂ could extend the setting time of SSC, decelerate the hydration rate of the matrix, and markedly reduce the quantity of hydrates. In contrast, the MSⅡ with a high γ-C₂S proportion had a negligible impact on the hydration process of SSC. Furthermore, the XRD patterns and TG results indicated that compared with MSⅡ, the incorporation of MSⅠ hindered the dissolution of gypsum and reduced the generation amount of hydration products, thus decreasing the compressive strength.

Under carbonation environments of different concentrations, the carbonation of calcium silicate in both types of magnesium slags enhanced the compressive strength of magnesium-doped slag-based SSC after carbonation to different extents. Compared with the control group, after 28-d carbonation, SSC doped with MSⅠ exhibited a carbonation depth, which was nearly twice greater than that of the control group (16.3 mm), while the content of hydration products post-carbonation was lower than that of the control group. Conversely, MSⅡ, which was abundant in γ-C₂S, demonstrated a superior protective effect on SSC during the carbonation process. After 28-d carbonation, the carbonation depth was only 6 mm, approximately 20% less than that of the control group. In addition, the content of hydration products post-carbonation remained consistent with the control group, and the strength after carbonation increased significantly.

For the compressive strength of carbonated SSC, the incorporation of slag containing various types of calcium and magnesium silicates could enhance the anti-carbonation performance of magnesium-doped slag SSC to different extents. However, compared to the MSⅡ containing γ-C₂S with a lower hydration activity and the MSⅠ with β-C₂S with a higher hydration activity, the reaction rate of SSC could be reduced. Before the carbonation, only a loose structure with a limited amount of C-A-S-H gel appeared. Conversely, the MSⅡ exhibited a higher proportion of γ-C₂S, which could have a low hydration activity and a high carbonation reactivity. This characteristic minimally affected the reaction rate of SSC, thereby ensuring that SSC doped with the MSⅡ demonstrated an excellent anti-carbonation performance in a carbonation environment. After the carbonation, there was a significant increase in matrix strength, and the microstructure became notably denser.

Key words

dicalcium silicate / magnesium slag / supersulfated cement / hydration / carbonation resistance

引用本文

李想, 王栋民, 王吉祥, 段开瑞, 房奎圳. 镁渣对超硫酸盐水泥水化与抗碳化性能的影响. 硅酸盐学报, 2026 , 54 (5) : 1512 -1523 . DOI: 10.14062/j.issn.0454-5648.20250105

Xiang LI, Dongmin WANG, Jixiang WANG, Kairui DUAN, Kuizhen FANG. Effects of Magnesium Slag on Hydration and Carbonization Resistance of Supersulfate Cement[J]. Journal of the Chinese Ceramic Society, 2026 , 54 (5) : 1512 -1523 . DOI: 10.14062/j.issn.0454-5648.20250105

基金

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国家重点研发项目(2024YFB3714800)
河南省级黄淮实验室创新专项项目(240700003)
鄂尔多斯市博士后科技项目(OPRF2503)

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2026年第54卷第5期

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文章信息

doi: 10.14062/j.issn.0454-5648.20250105

接收时间：2025-02-18
首发时间：2026-09-20
出版时间：2025-08-04

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出版历史

收稿日期：2025-02-18
修回日期：2025-04-20

基金

国家重点研发项目(2024YFB3714800)

河南省级黄淮实验室创新专项项目(240700003)

鄂尔多斯市博士后科技项目(OPRF2503)

作者信息

^1．中国矿业大学（北京）化学与环境工程学院，北京 100083

^2．清华大学土木工程学院，北京 100084

通讯作者:

王栋民（1965—），男，博士，教授。

王吉祥（1994—），男，博士。

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https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20250105

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2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

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