PSI - Issue 82

Samia M. Mohamed et al. / Procedia Structural Integrity 82 (2026) 213–219 S. M. Mohamed et al. / Structural Integrity Procedia 00 (2026) 000–000

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Fig. 4. Cumulative release of: a) Ca, b) Si, c) Pb, and d) V (Sun et al., 2022)

3. Conclusions This work highlights the key parameters that influence the leaching behavior of alkali-activated materials obtained from industrial byproducts such as GGBS, FA, and RM. GGBS-based AAMs have low leaching levels due to their compact microstructure and the development of stable C-A-S-H gels, especially when activated with sodium silicate. Systems based on fly ash are good at immobilizing cationic metals like Pb, Zn, and Cu. However, they often release more oxyanions like As and Cr(VI), particularly in extremely acidic or alkaline environments. Because of their intrinsic high alkalinity and amphoteric metal concentration, red mud-based AAMs exhibit complex leaching tendencies, with vanadium and chromium offering particularly difficult issues. Using activators such as Na 2 SiO 3 or hybrid systems, together with blending RM with GGBS or FA, greatly enhances heavy metal immobilization. References Bernal, S.A., Provis, J.L., Fernández-Jiménez, A., Krivenko, P. V., Kavalerova, E., Palacios, M., Shi, C., 2014a. Binder Chemistry – High Calcium Alkali-Activated Materials. pp. 59–91. Bernal, S.A., San Nicolas, R., Provis, J.L., Mejía de Gutiérrez, R., van Deventer, J.S.J., 2014b. Natural carbonation of aged alkali-activated slag concretes. Mater Struct 47, 693–707 Bobirică, C., Orbeci, C., Bobirică, L., Palade, P., Deleanu, C., Pantilimon, C.M., Pîrvu, C., Radu, I.C., 2020. Influence of red mud and waste glass on the microstructure, strength, and leaching behavior of bottom ash-based geopolymer composites. Sci Rep 10. Botti, R., Innocentini, M.D.M., Faleiros, T.A., Paschoalato, C.F.P.R., Mello, M.F., Franchin, G., Colombo, P., 2022. Leachability and basicity of Na‐ and K‐based geopolymer powders and lattices used as biodiesel catalysts. Int J Appl Ceram Technol 19, 794–802. Chen, Y.C., Ding, Y.C., Lee, W.H., Liu, X., Li, S., Xie, H., Luo, Q., 2022. The Study on the Properties and TCLP of GGBFS-Based Heavy Metal-Contaminated Soil Geopolymer. Crystals (Basel) 12. Duxson, P., Provis, J.L., Lukey, G.C., van Deventer, J.S.J., 2007. The role of inorganic polymer technology in the development of ‘green concrete.’ Cem Concr Res 37, 1590–1597. Gijbels, K., Landsberger, S., Samyn, P., Iacobescu, R.I., Pontikes, Y., Schreurs, S., Schroeyers, W., 2019. Radiological and non-radiological leaching assessment of alkali-activated materials containing ground granulated blast furnace slag and phosphogypsum. Gong, K., Cheng, Y., Daemen, L.L., White, C.E., 2019. In situ quasi-elastic neutron scattering study on the water dynamics and reaction mechanisms in alkali-activated slags. Physical Chemistry Chemical Physics 21, 10277–10292. Guo, B., Liu, B., Yang, J., Zhang, S., 2017. The mechanisms of heavy metal immobilization by cementitious material and thermal treatments. Hardjito, D., Wallah, S.E., Sumajouw, D.M.J., Rangan, B.V., 2004. On the Development of Fly Ash-Based Geopolymer Concrete. ACI Hyeok-Jung, K., Kang, S., Choe, G., 2018. Effect of Red Mud on Strength and Efflorescence in Pavement using Alkali-Activated Slag Cement. Ivan, E., Allouche, E.N., Eklund, S., Joshi, A.R., Kupwade-Patil, K., 2012. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash. Waste Management 32, 1521–1527. Izquierdo, M., Querol, X., Davidovits, J., Antenucci, D., Nugteren, H., Fernández-Pereira, C., 2009. Coal fly ash-slag-based geopolymers: Microstructure and metal leaching. J Hazard Mater 166, 561–566. Juenger, M.C.G., Winnefeld, F., Provis, J.L., Ideker, J.H., 2011. Advances in alternative cementitious binders. Cem Concr Res 41. Jun, Y., Kim, J.H., Han, S.H., Kim, T., 2021. Influence of seawater on alkali-activated slag concrete. Mater Struct 54, 121.