Mechanical, microstructural, and environmental-economic performance of cement-lithium slag stabilized clay as a pavement base

Abstract

The rapid growth in lithium production has led to a substantial accumulation of lithium slag, an industrial by-product. To promote the sustainable recycling of this waste and alleviate environmental concerns, this study explored the feasibility of incorporating lithium slag into cement-stabilized clay for use as a pavement base. The study comprehensively evaluated the mechanical properties, microstructural characteristics, and environmental-economic viability of cement-lithium slag stabilized clay with different lithium slag substitution rates (0, 6.25%, 12.5%, 18.75%, 25%, and 50%). Experimental findings indicated that the unconfined compressive strength (UCS) exhibited a convex trend where it initially rose and subsequently declined as the substitution rate increased, culminating in a peak value at an 18.75% substitution rate. Specifically, after 7 days of curing, the specimen with 18.75% substitution rate demonstrated a distinct strength enhancement of 37.76% over the 0 substitution rate, suggesting its suitability for higher-traffic pavement base. Regarding durability, although the UCS fluctuated (increasing then decreasing) with the number of wetting–drying cycles, the inclusion of lithium slag effectively improved the material’s resistance, with 18.75% again proving to be the optimal substitution rate. Specimen photos post-UCS testing and wetting–drying cycles revealed that cement-lithium slag stabilized clay exhibited the least severe failure characteristics at a 18.75% substitution rate. At the 18.75% substitution rate, reactive SiO₂ and Al₂O₃ in lithium slag underwent pozzolanic reactions with Ca(OH)₂ generated from cement hydration, forming additional C-S–H, networked C-A-S–H, and ettringite crystals, thereby increasing the strength of the stabilized clay. At the 18.75% substitution rate, cement-lithium slag stabilized clay achieved the best balance among compressive strength, environmental benefits, and economic efficiency. These findings offer valuable insights for utilizing cement-lithium slag stabilized clay in road base construction.

Keywords

Lithium slag / Stabilized clay / Unconfined compression strength / Wetting–drying cycles / Microstructure / CO₂ emission

References

[1] Xu D, Cui Y, Li Het al.. On the future of Chinese cement industry. Cement and Concrete Research, 2015, 78: 2-13

[2] Zuberi, M. J. S., & Patel, M. K. (2017). Bottom-up analysis of energy efficiency improvement and CO₂ emission reduction potentials in the Swiss cement industry. Journal of Cleaner Production, 142(4), 4294-4309. https://doi.org/10.1016/j.jclepro.2016.11.178

[3] Moumin G, Ryssel M, Zhao Let al.. CO₂ emission reduction in the cement industry by using a solar calciner. Renewable Energy, 2020, 145: 1578-1596

[4] Hills T, Florin N, Fennell P. Decarbonising the cement sector: A bottom-up model for optimising carbon capture application in the UK. Journal of Cleaner Production, 2016, 139: 1351-1361

[5] Sheshadri A, Marathe S, Sadowski Ł. Development of sustainable, high strength slag based alkali activated pavement quality concrete using agro-industrial wastes: Properties and life cycle analysis. International Journal of Pavement Engineering, 2024, 25(1 2410953

[6] Cheng D, Reiner D, Yang Fet al.. Projecting future carbon emissions from cement production in developing countries. Nature Communications, 2023, 141 8213

[7] Wang Y, Wen Z, Xu Met al.. The carbon-energy-water nexus of the carbon capture, utilization, and storage technology deployment schemes: A case study in China's cement industry. Applied Energy, 2024, 362 122991

[8] Hou H, Feng X, Zhang Yet al.. Energy-related carbon emissions mitigation potential for the construction sector in China. Environmental Impact Assessment Review, 2021, 89 106599

[9] Wang X, Zheng Z, Jia Wet al.. Response mechanism and evolution trend of carbon effect in the farmland ecosystem of the middle and lower reaches of the Yangtze River. Agronomy, 2024, 1410 2354

[10] Singh GB, Prasad VD. Environmental impact of concrete containing high volume fly ash and ground granulated blast furnace slag. Journal of Cleaner Production, 2024, 448 141729

[11] Adil G, Kevern JT, Mann D. Influence of silica fume on mechanical and durability of pervious concrete. Construction and Building Materials, 2020, 247 118453

[12] Wang Q, Yan P, Yang Jet al.. Influence of steel slag on mechanical properties and durability of concrete. Construction and Building Materials, 2013, 47: 1414-1420

[13] He Z, Li L, Du S. Mechanical properties, drying shrinkage, and creep of concrete containing lithium slag. Construction and Building Materials, 2017, 147: 296-304

[14] Zhou, E., Yang, Q., Zuo, X., & Zhang, M. (2025). Shear strength and dynamic deformation characteristics of clay stabilised with lime and lignin. Road Materials and Pavement Design, 1–21. https://doi.org/10.1080/14680629.2025.2475325

[15] Zhou E, Wang M, Liu Pet al.. Application of recycled lignin powder as a sustainable additive for soil improvement against water resistance. Road Materials and Pavement Design, 2024, 265): 1122-1136

[16] Jiang N, Wang Y, Chu Jet al.. Bio-mediated soil improvement: An introspection into processes, materials, characterization and applications. Soil Use and Management, 2021, 38(1): 68-93

[17] Koutous A, Hilali E. Reinforcing rammed earth with plant fibers: A case study. Case Studies in Construction Materials, 2021, 14 e00514

[18] Ahmad F, Rawat S, Yang Ret al.. Effect of metakaolin and ground granulated blast furnace slag on the performance of hybrid fibre-reinforced magnesium oxychloride cement-based composites. International Journal of Civil Engineering, 2025, 23(5): 853-868

[19] Ahmad, F., Rawat, S., Yang, R. C., Zhang, L., & Zhang, Y. X. (2025). Fire resistance and thermal performance of hybrid fibre-reinforced magnesium oxychloride cement-based composites. Construction and Building Materials, 472, 140867. https://doi.org/10.1016/j.conbuildmat.2025.140867

[20] Luo X, Huang L, Chen Zet al.. Alkali-fused lithium slag as a substitute for slag in one-part geopolymers: Mechanism of reactivity enhancement and microstructure. Construction and Building Materials, 2024, 442 137696

[21] Luo X, Huang L, Wei Let al.. A technique for preparing one-part geopolymers by activating alkali-fused lithium slag with solid sodium silicate. Construction and Building Materials, 2024, 435 136817

[22] Gu T, Zhang G, Wang Zet al.. Review: The formation, characteristics, and resource utilization of lithium slag. Construction and Building Materials, 2024, 432 136648

[23] Wang Y, Wang D, Zheng Yet al.. Thermal activation mechanism and activity evaluation of lithium slag: Insights from simulated hydration. Construction and Building Materials, 2024, 411 134615

[24] He Y, Kang Q, Lan Met al.. Mechanism and assessment of the pozzolanic activity of melting-quenching lithium slag modified with MgO. Construction and Building Materials, 2023, 363 129692

[25] Zhang Y, Yao M, Zhai Yet al.. Effect of lithium slag application on saline–alkali soil amelioration and vegetable growth. Sustainability, 2024, 16(8 3428

[26] Ahmad F, Qureshi M, Rawat Set al.. E-waste in concrete construction: Recycling, applications, and impact on mechanical, durability, and thermal properties—a review. Innovative Infrastructure Solutions, 2025, 106 246

[27] Nasir A, Butt F, Ahmad F. Enhanced mechanical and axial resilience of recycled plastic aggregate concrete reinforced with silica fume and fibers. Innovative Infrastructure Solutions, 2025, 101): 4

[28] Ahmad Z, Qureshi M, Ahmad Fet al.. Effect of macro synthetic fiber (MSF) on the behavior of conventional concrete and the concrete containing e-waste aggregates. Materials and Structures, 2025, 587 234

[29] Rahman SA, Shaikh FU, Sarker PK. A comprehensive review of properties of concrete containing lithium refinery residue as partial replacement of cement. Construction and Building Materials, 2022, 328 127053

[30] Rahman SA, Dodd A, Khair Set al.. Assessment of lithium slag as a supplementary cementitious material: Pozzolanic activity and microstructure development. Cement and Concrete Composites, 2023, 143 105262

[31] Ke Y, Li J, Yan Xet al.. Research progress on the activity stimulation of lithium slag in concrete. Sustainability, 2024, 1621 9549

[32] Liang J, Zou W, Tian Yet al.. Effect of high temperature on mechanical properties of lithium slag concrete. Scientific Reports, 2024, 14 11872

[33] Zhou M, Yan J, Fan Jet al.. Insight to workability, compressive strength and microstructure of lithium slag-steel slag based cement under standard condition. Journal of Building Engineering, 2023, 75 107076

[34] Rahman SA, Shaikh FUA, Sarker PK. Fresh, mechanical, and microstructural properties of lithium slag concretes. Cement and Concrete Composites, 2024, 148 105469

[35] Luo, Q., Wu, G., Zhang, X., Mao, Y. & Huang, S. (2017). Effects of lithium slag from yichun lepidolite on the durability of concrete. Journal of Nanchang University(Natural Science), 41(2), 122-124+130. https://doi.org/10.13764/j.cnki.ncdl.2017.02.005

[36] Li Y, Zhu W, Zheng Xet al.. Study on chloride attack resistance of concrete with lithium slag content. Journal of Building Engineering, 2024, 97 110723

[37] Li J, Huang S. Recycling of lithium slag as a green admixture for white reactive powder concrete. Journal of Material Cycles and Waste Management, 2020, 22: 1818-1827

[38] Amin MTE, Sarker PK, Shaikh FUA. Transport properties of concrete containing lithium slag. Construction and Building Materials, 2024, 416 135073

[39] Qin, Y., Chen, J., Li, Z. & Zhang, Y. (2019). The mechanical properties of recycled coarse aggregate concrete with lithium slag. Advances in Materials Science and Engineering, 1, 12. https://doi.org/10.1155/2019/8974625

[40] He Z, Du S, Chen D. Microstructure of ultra high performance concrete containing lithium slag. Journal Of Hazardous Materials, 2018, 353: 35-43

[41] Chen, S., Zhou, Y., Liu, L. & Chen, Z. (2023). Effect of lithium slag on mechanical properties of cement composite soil. Journal of Drainage and Irrigation Machinery Engineering, 41(11), 1142–1147(2023). https://link.cnki.net/urlid/32.1814.TH.20221226.0834.001

[42] Chen Z, Chen S, Liu Let al.. Effects of lithium slag on the frost resistance of cement-soil. Materials, 2022, 15(16 5531

[43] Hu W, Li K, Yin Wet al.. Effects of wetting–drying cycles on the macro and micro properties of the cement-stabilized soil with curing agent. Buildings, 2024, 146 1716

[44] Huang K, Fang Z, Cai Get al.. Macro and microscopic characteristics of soft soil stabilized by Portland cement-soda residue under dry-wet cycling. Construction and Building Materials, 2024, 428 136347

[45] Zheng, X., Liu, S., Cai, G. & Cao, Q. (2016). Experimental study on drying-wetting properties of carbonated reactive MgO-stabilized soils. Chinese Journal of Geotechnical Engineering, 38(2), 297-304, in Chinese. https://link.cnki.net/urlid/32.1124.tu.20150825.1139.012

[46] Zeng L, Bian X, Weng Jet al.. Wetting-drying effect on the strength and microstructure of cement-phosphogypsum stabilized soils. Journal of Rock Mechanics and Geotechnical Engineering, 2024, 163): 1049-1058

[47] Wassermann A, Abdallah A, Cuisinier O. Impact of wetting and drying cycles on the mechanical behaviour of a cement-treated soil. Transportation Geotechnics, 2022, 36 100804

[48] Neramitkornburi A, Horpibulsuk S, Shen SLet al.. Durability against wetting–drying cycles of sustainable lightweight cellular cemented construction material comprising clay and fly ash wastes. Construction and Building Materials, 2015, 77: 41-49

[49] Ministry of Transport of the People’s Republic of China. (2020). Test methods of soils for highway engineering (JTG 3430-2020). China Communications Press.

[50] Ministry of Construction of the People’s Republic of China; General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China. (2007). Standard for engineering classification of soil (GB/T 50145-2007). China Planning Press.

[51] General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. (2017). Methods for chemical analysis of cement (GB/T176-2017). Standards Press of China.

[52] Ministry of Transport of the People’s Republic of China. (2015). Technical guidelines for construction of highway roadbases (JTG/T F20-2015). China Communications Press.

[53] Ministry of Transport of the People’s Republic of China. (2009). Test methods of materials stabilized with inorganic binders for highway engineering (JTG E51-2009). China Communications Press.

[54] ASTM. (2015). Standard test methods for wetting and drying compacted soil-cement mixtures (ASTM D559/D559M-15). ASTM International.

[55] Wang Z, Wang D. Durability of industrial by-products combined with cement-solidified sludge subjected to immersion and cyclic wetting–drying in various fluids. Acta Geotechnica, 2023, 18: 6849-6874

[56] Hoy M, Tran NQ, Suddeepong Aet al.. Wetting-drying durability performance of cement-stabilized recycled materials and lateritic soil using natural rubber latex. Construction and Building Materials, 2023, 403 133108

[57] Zhang W, Xu H, Wang Wet al.. Study on recycling and utilization of phosphogypsum and lithium slag in vertical barrier materials. Construction and Building Materials, 2024, 438 137301

[58] Zhai M, Zhao J, Wang Det al.. Hydration properties and kinetic characteristics of blended cement containing lithium slag powder. Journal of Building Engineering, 2021, 39 102287

[59] Tan H, Li X, He Cet al.. Utilization of lithium slag as an admixture in blended cements: Physico-mechanical and hydration characteristics. Journal of Wuhan University of Technology-Materials Science Edition, 2015, 30: 129-133

[60] Hu P, Guo W, Wei L. Applicability study on modified argillaceous slate as subgrade filling for high-speed railway. Applied Sciences (Basel), 2022, 12(4 2227

[61] Brue F, Davy CA, Skoczylas Fet al.. Effect of temperature on the water retention properties of two high performance concretes. Cement and Concrete Research, 2012, 422): 384-396

[62] Kouby AL, Guimond-Barrett A, Reiffsteck Pet al.. Influence of drying on the stiffness and strength of cement-stabilized soils. Geotechnical and Geological Engineering, 2018, 36: 1463-1474

[63] Yangsukkasem N, Suebsuk J, Kampala Aet al.. Durability against cyclic wetting-drying of cement-stabilized loess subgrade for railway in tropical semi-arid regions. Construction and Building Materials, 2024, 455 139123

[64] Chen S, Chen F, Chen Wet al.. A study on mechanical properties of modified soil–cement mixed with ferronickel slag powder under dry–wet cycles in marine environments. Journal of Marine Science and Engineering, 2023, 11(9 1684

[65] Wang J, Gao C, Tang Jet al.. The multi-scale mechanical properties of calcium-silicate-hydrate. Cement and Concrete Composites, 2023, 140 105097

[66] Hou D, Zhu Y, Lu Yet al.. Mechanical properties of calcium silicate hydrate (C-S-H) at nano-scale: A molecular dynamics study. Materials Chemistry and Physics, 2014, 1463): 503-511

[67] Zaheer MM, Tabish M. The durability of concrete made up of sugar cane bagasse ash (scba) as a partial replacement of cement: A review. Arabian Journal for Science and Engineering, 2023, 48: 4195-4225

[68] Siddique R. Utilization of silica fume in concrete: Review of hardened properties. Resources, Conservation and Recycling, 2011, 55(11): 923-932

[69] He Z, Li L, Du S. Creep analysis of concrete containing rice husk ash. Cement and Concrete Composites, 2017, 80: 190-199

[70] Roosz C, Vieillard P, Blanc Pet al.. Thermodynamic properties of C-S-H, C-A-S-H and M-S-H phases: Results from direct measurements and predictive modelling. Applied Geochemistry, 2018, 92: 140-156

[71] Hay R, Li J, Celik Ket al.. Phase evolution, micromechanical properties, and morphology of calcium (alumino)silicate hydrates C-(A-)S-H under carbonation. Cement and Concrete Research, 2022, 152 106683

[72] Plassard C, Lesniewska E, Pochard Iet al.. Investigation of the surface structure and elastic properties of calcium silicate hydrates at the nanoscale. Ultramicroscopy, 2004, 100(3–4): 331-338

[73] Thomas JJ, Jennings HM, Allen AJ. Relationships between composition and density of tobermorite, jennite, and nanoscale CaO-SiO₂-H₂O. The journal of physical chemistry C, 2010, 114(17): 7594-7601

[74] Pelisser F, Gleize PJP, Mikowski A. Effect of the Ca/Si molar ratio on the micro/nanomechanical properties of synthetic C-S-H measured by nanoindentation. The journal of physical chemistry C, 2012, 116(32): 17219-17227

[75] Geng G, Myers RJ, Qomi MJet al.. Densification of the interlayer spacing governs the nanomechanical properties of calcium-silicate-hydrate. Scientific Reports, 2017, 7 10986

[76] Abdolhosseini Qomi MJ, Krakowiak KJ, Bauchy Met al.. Combinatorial molecular optimization of cement hydrates. Nature Communications, 2014, 5 4960

[77] Manzano H, Dolado JS, Ayuela A. Elastic properties of the main species present in Portland cement pastes. Acta Materialia, 2008, 57(5): 1666-1674

[78] Geng G, Myers RJ, Li Jet al.. Aluminum-induced dreierketten chain cross-links increase the mechanical properties of nanocrystalline calcium aluminosilicate hydrate. Scientific Reports, 2017, 7 44032

[79] Yuan L, Liu L, Sun Let al.. Feasibility study of lithium slag as cementitious material with high-content application in cement stabilized macadam bases. Construction and Building Materials, 2024, 457 139224

[80] He M, Yang Z, Li Net al.. Strength, microstructure, CO₂ emission and economic analyses of low concentration phosphoric acid-activated fly ash geopolymer. Construction and Building Materials, 2023, 374 130920

[81] O’Born, R., Brattebø, H., Iversen, O. M. K., Miliutenko, S., & Potting, J. (2016). Quantifying energy demand and greenhouse gas emissions of road infrastructure projects: An LCA case study of the Oslo fjord crossing in Norway. European Journal of Transport and Infrastructure Research,16(3). https://doi.org/10.18757/ejtir.2016.16.3.3152

[82] Kalateh-Ahani M, Sarani A. Performance-based optimal design of cantileverretaining walls. Periodica Polytechnica Civil Engineering, 2019, 63(2): 660-673

[83] Pandey SP, Yu H, Lau Cet al.. New coal char-based building products: Manufacturing, engineering performance, and techno-economic analysis for the USA market. Sustainability, 2024, 16(5 1854

[84] Yuan L, Liu L, Sun Let al.. Composite utilization of lithium slag and feldspar powder in cement stabilized macadam: Mix design, durability, and microstructure. Construction and Building Materials, 2025, 489 142412

[85] Cao X, Guan B, Yu Jet al.. Mechanical properties and heavy metals immobilization of lithium slag stabilized by magnesium slag as road subbase material. Journal of Cleaner Production, 2025, 505 145484

[86] Lemougna PN, Yliniemi J, Ismailov Aet al.. Recycling lithium mine tailings in the production of low temperature (700–900 C) ceramics: Effect of ladle slag and sodium compounds on the processing and final properties. Construction and Building Materials, 2019, 221: 332-344

[87] Shen S, Tian J, Zhu Yet al.. Synthesis of industrial solid wastes based geopolymer foams for building energy conservation: Effects of metallic aluminium and reclaimed materials. Construction and Building Materials, 2022, 328 127083

[88] State Environmental Protection Administration of of the People’s Republic of China.; State Bureau of Technical Supervision of the People’s Republic of China. (1996). Integrated wastewater discharge standard (GB 8978-1996). China Environmental Science Press.

[89] State Environmental Protection Administration of of the People’s Republic of China; General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China. (2007). Identification standards for hazardous wastes-Identification for extraction toxicity (GB 5085.3-2007). China Environmental Science Press.

[90] Dai BB, Zou Y, He Yet al.. Solidification experiment of lithium-slag and fine-tailings based geopolymers. Sustainability, 2023, 155 4523

[91] Fan J, Yan J, Zhou Met al.. Heavy metals immobilization of ternary geopolymer based on nickel slag, lithium slag and metakaolin. Journal of Hazardous Materials, 2023, 453 131380

[92] Raza MU, Butt F, Ahmad Fet al.. Seismic safety assessment of buildings and perceptions of earthquake risk among communities in Mingora, Swat, Pakistan. Innovative Infrastructure Solutions, 2025, 104): 1-18

Funding

Zhenjiang Science and Technology Program(CS2024002)

RIGHTS & PERMISSIONS

The Author(s)