闵前燊,张志鹏,刘志超.α-CS的制备及其碳化硬化性能研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2026060029.

MIN Q S, ZHANG Z P, LIU Z C. Preparation of α-CS and its carbonation-hardening performance[J]. Journal of Henan Polytechnic University(Natural Science)， doi:10.16186/j.cnki.1673-9787.2026060029.

α-CS的制备及其碳化硬化性能研究(网络首发)

闵前燊1，张志鹏3，刘志超1，2

1.武汉理工大学 材料科学与工程学院，湖北 武汉 430070；2.武汉理工大学 硅酸盐科学与先进建材全国重点实验室，湖北 武汉 430070；3.湖北工业大学 材料与化学工程学院，湖北 武汉 430068

摘要: 目的 针对实验室固相合成α-CS熟料时烧成制度对矿相组成的影响，以及α-CS碳化硬化过程与强度形成机制尚需明确的问题，以Ca(OH)₂和SiO₂为原料制备α-CS熟料，研究重复煅烧制度对熟料矿相组成的影响，并揭示高α-CS含量熟料在CO₂养护条件下的碳化硬化行为及其微观作用机制。方法 采用固相烧成法制备不同重复煅烧次数的α-CS熟料，利用X射线衍射分析结合内标法对熟料矿相进行定量表征，并筛选高α-CS含量熟料。通过抗压强度、热重-差热分析、pH、电导率、温度监测、X射线衍射及背散射电子显微分析，表征碳化过程中试样的力学性能、碳化程度、离子溶出与沉淀行为、反应放热特征及硬化产物形貌。结果 重复煅烧显著改变熟料矿相。未重复煅烧中α-CS为34.4%，并含较多C₃S₂与γ-C₂S；重复煅烧1、2次后，α-CS分别升至64.9%，89.7%；增至3次时回落至85.9%，非晶相升至14.1%。取煅烧2次熟料碳化养护，富CO₂下快速硬化，碳化24 h抗压强度118.6 MPa、碳化程度41.5%。碳化初期二者均快速增长；通CO₂后pH速降、电导率先降后升、温度于7 min达峰。产物以文石型CaCO₃和硅胶为主，硬化体残留少量未反应α-CS。结论 CaCO₃和硅胶在颗粒间及孔隙中协同沉积，增强颗粒桥连、降低孔隙率，从而促进硬化体强度发展。研究结果可为α-CS熟料烧成制度优化及其在固碳胶凝材料中的应用提供参考。

关键词:α-CS；煅烧制度；碳化硬化；力学性能；微观结构

doi: 10.16186/j.cnki.1673-9787.2026060029

基金项目:国家重点研发计划(2024YFF0508300)

收稿日期：2026-06-23

修回日期：2026-08-18

网络首发日期：2026-09-09

Preparation of α-CS and its carbonation-hardening performance (Online)

MIN Qianshen1, ZHANG Zhipeng3, LIU Zhichao1, 2

1. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China; 2. State Key Laboratory of Silicate Materials for Architectonics, Wuhan University of Technology, Wuhan 430070, Hubei, China; 3. School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, Hubei, China

Abstract: Objectives To clarify the effects of firing regimes on the phase composition during the laboratory solid-state synthesis of α-CS clinker, as well as the carbonation-hardening process and strength-development mechanism of α-CS, α-CS clinker was prepared from Ca(OH)₂ and SiO₂. The effects of repeated calcination on the phase composition of the clinker were investigated, and the carbonation-hardening behavior and microstructural mechanism of clinker with a high α-CS content under CO₂ curing were elucidated. Methods α-CS clinkers subjected to different numbers of repeated calcination cycles were prepared by a solid-state calcination method. Their phase compositions were quantitatively characterized by X-ray diffraction with an internal standard, and clinker with a high α-CS content was selected. The clinker powder was mixed with water at a water-to-solid ratio of 0.15, compacted into specimens, and cured at room temperature under 99.9% CO₂ at 0.3 MPa. Compressive strength, thermogravimetric-differential thermal analysis, pH, electrical conductivity, temperature evolution, X-ray diffraction, and backscattered electron imaging were used to characterize the mechanical properties, degree of carbonation, dissolution-precipitation behavior, heat-release characteristics, and morphology of the hardening products. Results Repeated calcination significantly altered the phase composition of the clinker. The α-CS content of the B0 sample without repeated calcination was 34.4%, with considerable amounts of C₃S₂ and γ-C₂S remaining. After one and two repeated calcination cycles, the α-CS content increased to 64.9% and 89.7%, respectively. With a further increase in calcination cycles, the α-CS content of the B3 sample decreased to 85.9%, whereas the amorphous-phase content increased to 14.1%. The B2 clinker exhibited rapid hardening under CO₂ curing, reaching a compressive strength of 118.6 MPa and a carbonation degree of 41.5% after 24 h. At the early carbonation stage, both compressive strength and degree of carbonation increased rapidly; after CO₂ introduction, the pH decreased rapidly, electrical conductivity first decreased and then increased, and specimen temperature reached its maximum at 7 min. The carbonation products were mainly CaCO₃, predominantly aragonite, and silica gel, while a small amount of unreacted α-CS remained. Conclusions Under the present experimental conditions, two repeated calcination cycles promoted α-CS formation and produced clinker with a high target-phase content. The carbonation-hardening process of α-CS comprised an initial rapid dissolution-nucleation-precipitation stage and a subsequent slow densification stage controlled by the product layer. The synergistic deposition of CaCO₃ and silica gel in interparticle spaces and pores enhanced particle bridging and reduced porosity, thereby promoting strength development. These results provide a reference for optimizing the firing regime of α-CS clinker and its application in carbonatable binder.

Key words: α-CS; calcination regime; carbonation hardening; mechanical properties; microstructure