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Material-Related Carbon and Functional Performance of D800 Non-Autoclaved Foam Concrete Modified with Fly Ash and Microsilica

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Author Affiliations

  • 1Department of Construction of Buildings and Industrial Structures, Tashkent State Transport University, Tashkent, Uzbekistan
  • 2Department of Construction of Buildings and Industrial Structures, Tashkent State Transport University, Tashkent, Uzbekistan

Int. Res. J. Environment Sci., Volume 15, Issue (4), Pages 85-95, October,22 (2026)

Abstract

The present study evaluates the environmental and functional performance of D800 non-autoclaved foam concrete in which Portland cement was partially replaced by fly ash and microsilica. A modified binder containing 15% fly ash and 5% microsilica was selected through preliminary screening and compared with a reference composition. The experimental program included density, compressive and flexural strength, thermal conductivity, and SEM observations. Environmental performance was assessed by a comparative material-related global warming potential (GWP) calculation using EPD- and LCI-based emission factors, together with performance-normalized carbon intensity and sensitivity analysis for the environmental burdens assigned to the secondary mineral components. The modified mixture reduced Portland-cement consumption by 20% and incorporated 83 kg/m³ of secondary industrial materials. Its 28-day compressive strength increased from 3.00 to 4.20 MPa, while thermal conductivity decreased from 0.270 to 0.221 W/(m•K). Material-related GWP declined from 355.16 to 311.09 kg CO₂-eq/m³, corresponding to a reduction of 12.4%, whereas carbon intensity decreased by 37.4%. Under a conservative sensitivity scenario, the modified mixture still maintained lower GWP and carbon intensity than the reference. These findings show that the proposed modification strategy improves resource efficiency without compromising functional performance. Overall, the optimized foam-concrete system incorporating fly ash and microsilica as partial cement replacements reduced cement demand and material-related carbon burden while maintaining improved mechanical and thermal performance relative to the reference composition.

References

  1. United Nations Environment Programme (2026)., Global Status Report for Buildings and Construction 2025–2026., UNEP and Global ABC.
  2. International Energy Agency (2023)., Cement: Net Zero Emissions Guide., International Energy Agency, Paris.
  3. Amran, Y. H. M., Farzadnia, N., & Abang Ali, A. A. (2015)., Properties and applications of foamed concrete; a review., Construction and Building Materials, 101, 990–1005.
  4. Fu, Y., Wang, X., Wang, L., & Li, Y. (2020)., Foam concrete: A state-of-the-art and state-of-the-practice review., Advances in Materials Science and Engineering, 2020, 6153602.
  5. Liu, J., Liu, Y., Ma, X., Xu, H., Wu, X., Liu, M., & Zhuge, Y. (2025)., Thermal performance optimisation of foam concrete for energy-efficient construction: A state-of-the-art review., Journal of Building Engineering, 112, 113899.
  6. Mohamad, A., Khadraoui, F., Boutouil, M., & Chateigner, D. (2023)., Influence of pozzolans and hemp shives on the properties of non-autoclaved foamed concrete., Materials, 16(2), 591.
  7. Gökçe, H. S., Hatungimana, D., & Ramyar, K. (2019)., Effect of fly ash and silica fume on hardened properties of foam concrete., Construction and Building Materials, 194, 1–11.
  8. Khan, A., Ali, A., Mehboob, S. S., Tayyab, A., Khan, D., Mursaleen, M., Rezzoug, A., & Ltifi, M. (2026)., Multi-objective optimization of thermal and mechanical properties of lightweight foam concrete with binary blend of fly ash and silica fume., Journal of Building Engineering, 120, 115387.
  9. Yaseen, N., Alcivar-Bastidas, S., Irfan-Ul-Hassan, M., Petroche, D. M., Qazi, A. U., & Ramirez, A. D. (2024)., Concrete incorporating supplementary cementitious materials: Temporal evolution of compressive strength and environmental life cycle assessment., Heliyon, 10(3), e25056.
  10. Rahla, K. M., Mateus, R., & Bragança, L. (2019)., Comparative sustainability assessment of binary blended concretes using supplementary cementitious materials (SCMs) and ordinary Portland cement (OPC)., Journal of Cleaner Production, 220, 445–459.
  11. Damineli, B. L., Kemeid, F. M., Aguiar, P. S., & John, V. M. (2010)., Measuring the eco-efficiency of cement use., Cement and Concrete Composites, 32(8), 555–562.
  12. International Organization for Standardization 14040 (2006)., Environmental management-Life cycle assessment - Principles and framework (ISO 14040:2006)., International Organization for Standardization, Geneva, Switzerland.
  13. International Organization for Standardization 14044 (2006)., Environmental management-Life cycle assessment-Requirements and guidelines (ISO 14044: 2006)., International Organization for Standardization, Geneva, Switzerland.
  14. International Organization for Standardization (2018)., Greenhouse gases — Carbon footprint of products — Requirements and guidelines for quantification (ISO 14067:2018)., International Organization for Standardization, Geneva, Switzerland.
  15. International Organization for Standardization (2017)., Sustainability in buildings and civil engineering works — Core rules for environmental product declarations of construction products and services (ISO 21930:2017)., International Organization for Standardization, Geneva, Switzerland.
  16. European Committee for Standardization. (2019)., Sustainability of construction works — Environmental product declarations — Core rules for the product category of construction products (EN 15804:2012+A2:2019)., European Committee for Standardization, Brussels, Belgium.
  17. Wernet, G., Bauer, C., Steubing, B., Reinhard, J., Moreno-Ruiz, E., & Weidema, B. (2016)., The ecoinvent database version 3 (Part I): Overview and methodology., The International Journal of Life Cycle Assessment, 21(9), 1218–1230.
  18. LİMAK Cement Industry and Trade Inc. (2025)., CEM PLUS+ {CEM II/A-LL 42.5 N}: Environmental Product Declaration., International EPD System, EPD-IES-0026521:001.
  19. SCR-Sibelco NV. (2026)., Silica Sand Dry (Bulk): Environmental Product Declaration., International EPD System, EPD-IES-0030293:001.
  20. Masheed Trading & Transportation Co. Ltd. (2026)., Fly Ash: Environmental Product Declaration., International EPD System, EPD-IES-0032541:001.
  21. Masheed Trading & Transportation Co. Ltd. (2026)., Micro Silica: Environmental Product Declaration., International EPD System, EPD-IES-0032939:002.
  22. ADING-BULGARIA EOOD. (2025)., Admixture for Concrete “Superfluid 21AM”: Environmental Product Declaration., International EPD System, EPD-IES-0025863:002.
  23. Mapei S.P.A. (2024)., Mapescreed Foamer L: Environmental Product Declaration., International EPD System, EPD-IES-0010978:001.
  24. Siam City Cement (Vietnam) Ltd. (2026)., INSEE LAVILLA: Environmental Product Declaration., International EPD System, EPD-IES-0031428:001.
  25. Al Rashed Cement Company (2025)., Micro Silica: Environmental Product Declaration., International EPD System, EPD-IES-0020838:002.
  26. Wang, N., Sun, X., Zhao, Q., Yang, Y., & Wang, P. (2020)., Leachability and adverse effects of coal fly ash: A review., Journal of Hazardous Materials, 396, 122725.