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BULLETIN OF THE CHINESE CERAMIC SOCIETY ›› 2026, Vol. 45 ›› Issue (8): 2760-2769.DOI: 10.16552/j.cnki.issn1001-1625.2026.0120

• Solid Waste and Eco-Materials • Previous Articles     Next Articles

Mechanisms of Alkali-Silica Reaction Inhibition in Concrete Using Composite Solid-Waste Mineral Admixtures as Fly-Ash Replacements

XU Qing1(), YANG Shuqing1(), FENG Wei2, LI Lin3, CUI Hongzhi1   

  1. 1.Key Laboratory of Coastal Urban Resilient Infrastructures,Ministry of Education,College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China
    2.Key Laboratory of Water Engineering Materials,Ministry of Water Resources,China Institute of Water Resources and Hydropower Research,Beijing 100038,China
    3.Sichuan Port and Shipping Investment Group Co. ,Ltd. ,Leshan 614000,China
  • Received:2026-02-02 Revised:2026-02-25 Online:2026-08-15 Published:2026-09-01
  • Contact: YANG Shuqing

Abstract:

To address the challenges associated with the uneven regional distribution of fly ash resources and the limited availability of a stable local supply for dam construction, this study developed a composite solid-waste mineral admixture derived by solid wastes from engineering-side areas as a substitute for fly ash to mitigate alkali-silica reaction (ASR) in concrete while enabling in situ resource utilization of solid wastes. The reaction activity and mitigation effectiveness were evaluated through activity index, hydration heat, and expansion rate, while the underlying suppression mechanisms were elucidated by combining pore-solution ionic analysis with backscattered electron scanning electron microscopy. The influence on material performance was further assessed using compressive strength testing, mercury intrusion porosimetry, and thermogravimetric analysis. The results demonstrate that the composite solid-waste mineral admixture exhibits a lime consumption activity of up to 52.3%, comparable to that of fly ash. A composite solid-waste mineral admixture replacement level of not less than 20% is sufficient to control ASR expansion below the specified limit. Pore-solution ionic analysis result reveals a mitigation mechanism characterized by the reduction of alkali metal ions and the modulation of aluminum species. Thermogravimetric and porosity results indicate that, under the same mix proportion, Ca(OH)2 is continuously consumed and the pore structure gradually densifies with curing age. Overall, this study provides a low-carbon mitigation strategy for ASR control in concrete in regions with constrained fly ash supply.

Key words: composite solid-waste mineral admixture, alkali-silica reaction, issueary cementitious material, pore structure, fly ash replacement, mortar-bar expansion

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