Aqueous Carbonation of Steel Slag: Characteristics and Properties of Steel Slag as Supplementary Cementitious Materials

Abstract

To investigate the effects of wet carbonation on the composition of steel slag and the relationship between its carbonation degree and hydration reactivity, this study systematically compares steel slag with low carbonation (1 hour of carbonation) and high carbonation (4 hours of carbonation), focusing on their impact on the hydration process and mechanical properties of cement-based composites. Carbonated steel slag contains a significant amount of calcium carbonate, dicalcium silicate and silica gel, exhibiting excellent cementitious activity and micro-aggregate effects, making it a high-quality supplementary cementitious material for cement-based products. The results indicate that wet carbonation leads to the formation of calcite-type calcium carbonate and silica gel in the steel slag. These components accelerate the generation of hydration products, increase the specific surface area of the slag, and alter its hydration reactivity and pozzolanic activity. Tests showed that when 10% of this carbonated of 1 h steel slag powder was incorporated into cement paste, the 3-day and 28-day compressive strengths reached 25.4 and 42.4 MPa, respectively, demonstrating a significant improvement compared to the non-carbonated steel slag group. Excessive carbonation reduces the early strength (3 days) of cement mortar with high steel slag content. In contrast, steel slag with a low degree of carbonation enhances the later strength (28 days) of the mortar, with this improvement being particularly pronounced at low incorporation levels. Its excellent micro-aggregate filling effect and nucleation action synergistically promote the hydration process, further optimizing the pore structure of the hardened paste. Meanwhile, the introduction of carbonated steel slag effectively regulates the morphology and distribution of hydration products, enhancing the compactness of the interfacial transition zone. XRD and SEM analyses reveal that C-S-H gels and calcium carbonate whiskers interweave to form a dense network structure, significantly improving the integrity of the matrix.

Keywords

steel slag / aqueous carbonation / microstructure / supplementary cementitious materials / cementitious properties

References

[1] Fang Y F, et al.Semi-dry and Aqueous Carbonation of Steel Slag: Characteristics and Properties of Steel Slag as Supplementary Cementitious Materials[J]. Construction and Building Materials, 2024, 425: 135 981.

[2] Liu P, Mo L, Zhang ZEffects of Carbonation Degree on the Hydration Reactivity of Steel Slag in Cement-based Materials[J]. Construction and Building Materials, 2023, 370130 653.

[3] Zhao Y L, Zheng Y, Cui K, et al.Development of Ultrafine and Highly Reactive SCMs via Combined CO₂ and Mechanical Activation of Steel Slag[J]. Chemical Engineering Journal, 2025, 516163 999.

[4] Zhang Y, Shan J, Ma Z, et al.Effects of Ethylenediaminetetraacetic Acid on the Properties of Accelerated Carbonated Steel Slag as Supplementary Cementitious Materials[J]. Construction and Building Materials, 2025, 487142 093.

[5] Liu P, Zhong J, Zhang M, et al.Effect of CO2 Treatment on the Microstructure and Properties of Steel Slag Supplementary Cementitous Materials[J]. Construction and Building Materials, 2021, 309125 171.

[6] Zare P, Narani S S, Abbaspour M, et al.Experimental Investigation of Non-stabilized and Cement-stabilized Rammed Earth Reinforcement by Waste Tire Textile Fibers (WTTFs)[J]. Constr. Build. Mater., 2020, 260120 432.

[7] Li X, Mehdizadeh H, Ling T CEnvironmental, Economic and Engineering Performances of Aqueous Carbonated Steel Slag Powders as Alternative Material in Cement Pastes: Influence of Particle Size[J]. Science of The Total Environment, 2023, 903166 210.

[8] Fang Y, Su W, Zhang Y, et al.Effect of Accelerated Precarbonation on Hydration Activity and Volume Stability of Steel Slag as a Supplementary Cementitious Material[J]. Journal of Thermal Analysis and Calorimetry, 2022, 147(11): 6 181-6 191.

[9] Yang S, Mo L, Lu DEffects of Sodium Aluminate on Fleeting Semi-dry Carbonation and Properties of Steel Slag Powders in Low Concentration CO₂ Atmosphere[J]. Cement and Concrete Composites, 2024, 150105 551.

[10] Yang S, Mo L, Deng MEffects of Ethylenediamine Tetra-acetic Acid (EDTA) on the Accelerated Carbonation and Properties of Artificial Steel Slag Aggregates[J]. Cem. Concr. Compos., 2021, 118103 948.

[11] Yu X, Chen DPreparation and Characterization of Epoxy/slag Composite for Cement Slurry Applications[J]. Journal of Applied Polymer Science, 2016, 13317.

[12] Zhang X, Qian C, Ma Z, et al.Study on Preparation of Supplementary Cementitious Material Using Microbial CO2 Fixation of Steel Slag Powder[J]. Construction and Building Materials, 2022, 326126 864.

[13] Shi Y, Chen H, Wang J, et al.Preliminary Investigation on the Pozzolanic Activity of Superfine Steel Slag[J]. Construction and Building Materials, 2015, 82227-234.

[14] Vossmeyer T, Katsikas L, Giersig M, et al.CdS Nanoclusters: Synthesis, Characterization, Size Dependent Oscillator Strength, Temperature Shift of the Excitonic Transition Energy, and Reversible Absorbance Shift[J]. The Journal of Physical Chemistry, 1994, 98(31): 7 665-7 673.

[15] Luo Z, Wang Y, Yang G, et al.Effect of Curing Temperature on Earbonation Behavior of Steel Slag Compacts[J]. Constr. Build. Mater., 2021, 291: 123 369.

[16] Rui Y, Qian CCO₂-fixing Steel Slag on Hydration Characteristics of Cement-based Materials[J]. Constr. Build. Mater., 2022, 354129 193.

[17] Mahoutian M, Chaallal O, Shao YPilot Production of Steel Slag Masonry Blocks[J]. Canadian Journal of Civil Engineering, 2018, 45(7): 537-546.

[18] Gao M, Wang J, Sha W, et al.Physico-mechanical Properties and Synergistic Hydration Mechanism of Steel Slag-GBFS Based Alkali-activated Composites Incorporated with Silica Fume[J]. Journal of Materials Research and Technology, 2025, 363 327-3 341.

[19] Zhao J, Wang D, Yan P, et al.Self-cementitious Property of Steel Slag Powder Blended with Gypsum[J]. Construction and Building Materials, 2016, 113: 835-842.

[20] Yang S, Mo L, Deng MEffects of Ethylenediamine Tetra-acetic Acid (EDTA) on the Accelerated Carbonation and Properties of Artificial Steel Slag Aggregates[J]. Cement and Concrete Composites, 2021, 118: 103 948.

[21] Mu Y, Liu Z, Wang F, et al.Carbonation Characteristics of γ-dicalcium Silicate for Low-carbon Building Material[J]. Constr. Build. Mater., 2018, 177322-331.

[22] Zhao Y, Chen B, Zhao Y, et al.Properties, Phases and Microstructure Evolution of Blended Cement Containing BOF Slag: Effect of Two-step Carbonation Process[J]. Construction and Building Materials, 2025, 458: 139 704.

[23] Zhong X, Li L, Jiang YElucidating the Dominant and Interaction Effects of Temperature, CO₂ Pressure and Carbonation Time in Carbonating Steel Slag Blocks[J]. Constr. Build. Mater., 2021, 302124 158.

[24] Zhang Y, Li G, Zhang S, et al.Enhancing Mechanical Properties of Carbonated Steel Slag Through Surfactant-assisted CaCO₃ Crystallization[J]. Construction and Building Materials, 2024, 451138 800.

[25] Chang J, Zhang X, Yang G Y, et al.Effects of Pozzolanic Reaction on Carbonation Degree and Strength of Steel Slag Compacts Containing Zeolite[J]. Construction and Building Materials, 2021, 277122 334.

[26] Zhang K, Zeng H, Li N, et al.A Preliminary Exploration of Waste Red-bed as A Supplementary Cementitious Material[J]. Journal of Cleaner Production, 2024, 471143 426.

[27] Yu Q, Liu T J, Cai S, et al.A Review on the Effect from Steel Slag on the Growth of Microalgae[J]. Processes, 2021, 9(5): 769.

[28] Benhelal E, Rashid M I, Holt C, et al.The Utilisation of Feed and Byproducts of Mineral Carbonation Processes as Pozzolanic Cement Replacements[J]. Journal of Cleaner Production, 2018, 186499-513.

[29] Tang P, Li Y, Rong P, et al.Improvement of CO₂ Uptake in Artificial Aggregates Derived from Steel Slag by Introducing Inert Particles: The Role of Regulating CO₂ Transport Channel[J]. Construction and Building Materials, 2025, 482141 708.

[30] Livingston R A, Neumann D A, Allen A J, et al.Application of Neutron Scattering to Portland Cement[J]. Neutron News, 2000, 11(4): 18-24.

[31] Chen R, Li G, Mi Z, et al.Experimental and Simulation Study of Calcium Carbonate Non-uniform Distribution Characteristics of Bio-cemented Sand[J]. Case Studies in Construction Materials, 2024, 21e03 926.

[32] Jinhui T, Min D, Aiguo W, et al.Influence of the Cement Fineness on Strengths of Cement Pastes Containing High Phosphorus Slag[J]. Journal of Materials in Civil Engineering, 2015, 27(12): 04 015 047.

[33] Li J, Ni W, Wang X, et al.Mechanical Activation of Medium Basicity Steel Slag Under Dry Condition for Carbonation Curing[J]. Journal of Building Engineering, 2022, 50104 123.

[34] Liu G, Schollbach K, Li P, et al.Valorization of Converter Steel Slag into Eco-friendly Ultra-high Performance Concrete by Ambient CO₂ Pre-treatment[J]. Constr. Build. Mater., 2021, 280122 580.

[35] Mahoutian M, Shao YProduction of Cement-free Construction Blocks from Industry Wastes[J]. Journal of Cleaner Production, 2016, 1371 339-1 346.

[36] Wang Q, Yang J, Chen HLong-term Properties of Concrete Containing Limestone Powder[J]. Materials and Structures, 2017, 50(3): 168.

[37] Fang Y, Chang JMicrostructure Changes of Waste Hydrated Cement Paste Induced by Accelerated Carbonation[J]. Construction and Building Materials, 2015, 76360-365.

[38] Wang X, Gong C, Lei J, et al.Effect of Silica Fume and Nano-silica on Hydration Behavior and Mechanism of High Sulfate Resistance Portland Cement[J]. Construction and Building Materials, 2021, 279122 481.

[39] Yang H, Monasterio M, Zheng D, et al.Effects of Nano Silica on the Properties of Cement-based Materials: A Comprehensive Review[J]. Construction and Building Materials, 2021, 282122 715.

[40] Berryman E J, Williams-Jones A E, Migdisov A ASteel Slag Carbonation in A Flow-through Reactor System: The Role of Fluid-flux[J]. Journal of Environmental Sciences, 2015, 27266-275.

Rights & permissions

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature