aesafhi

• Safhi, Amine el Mahdi; Mejjad, Nezha; Ghribi, Mounir; Pilehvar, Shima & Kioumarsi, Mahdi (2026). Benchmarking sustainable blue economy in Canada and Norway: A comparative KPI-based assessment. Marine Policy. ISSN 0308-597X. 195. doi: 10.1016/j.marpol.2026.107298. Full text in Research Archive
• Aliyari, Mostafa; Safhi, Amine el Mahdi; Pilehvar, Shima; Nehdi, Moncef L. & Kioumarsi, Mahdi (2026). High-fidelity data-driven multi-objective design of class F fly ash–geopolymer concrete. Powder Technology. ISSN 0032-5910. 469(2). doi: 10.1016/j.powtec.2025.121900. Full text in Research Archive Show summary

  Class F fly-ash geopolymers (FA-GPCs) can slash the CO₂ burden of structural concrete, yet their mix design still relies on costly trial-and-error. The first geometry-normalized database of FA-only geopolymer concretes was assembled—799 mixes from 67 publications, every reported strength converted to the 150 Ø 300 mm cylinder equivalent—and interrogate it with a three-scenario, data-availability workflow. Eighteen machine-, deep- and hybrid-learning models are benchmarked; a Voting ensemble predicts 7–28 days compressive strength with an R2 of 0.962, while an LSTM + XGBoost hybrid forecasts mix-specific CO₂ footprints at an R2 of 0.996. SHAP analysis reveals that the Si/Al ratio and initial curing temperature dominate early-age strength, whereas total Na₂SiO₃/NaOH and Na₂O/binder ratios control embodied carbon, underscoring an inherent strength–footprint trade-off. These surrogate models feed a multi-objective optimizer (NSGA-II, confirmed superior to NSGA-III and MOEA/D) that explores the 1st–99th-percentile bounds of 11 mix variables. The resulting Pareto fronts deliver eco-efficient recipes reaching 65 MPa at ≤30 kg CO₂/m3 (at 90-d curing age) and extend to 87 MPa under relaxed carbon targets. Compared with state-of-the-art optimization that rely on mixed precursors or un-normalized data, the proposed pipeline widens the design space, lifts strength by 10–20 MPa and trims CO₂ by up to 70 %. The framework— in this order: data curation, geometry correction, scenario-specific ML, evolutionary optimization—cuts trial batching efforts and offers practitioners ready-to-deploy, class F FA-GPC mixtures while providing a transparent template for other alkali-activated binders which was confirmed by an experimental validation.

• Zri, Abdeljalil; Abriak, Nor-Edine; Safhi, Amine el Mahdi; Pilehvar, Shima & Kioumarsi, Mahdi (2025). Performance Limits of Hydraulic-Binder Stabilization for Dredged Sediments: Comparative Case Studies. Buildings. 15(14). doi: 10.3390/buildings15142484. Full text in Research Archive Show summary

  Maintenance dredging produces large volumes of fine sediments that are commonly discarded, despite increasing pressure for beneficial reuse. Lime–cement stabilization offers one pathway, yet field performance is highly variable. This study juxtaposes two French marine dredged sediments—DS-F (low plasticity, organic matter (OM) ≈ 2 wt.%) and DS-M (high plasticity, OM ≈ 18 wt.%)—treated with practical hydraulic road binder (HRB) dosages. This is the first French study that directly contrasts two different DS types under identical HRB treatment and proposes practical boundary thresholds. Physical indexes (particle size, methylene-blue value, Atterberg limits, OM) were measured; mixtures were compacted (Modified Proctor) and tested for immediate bearing index (IBI). IBI, unconfined compressive strength, indirect tensile strength, and elastic modulus were determined. DS-F reached IBI ≈ 90–125%, UCS ≈ 4.7–5.9 MPa, and ITS ≈ 0.40–0.47 MPa with only 6–8 wt.% HRB, satisfying LCPC-SETRA class S2–S3 requirements for road subgrades. DS-M never exceeded IBI ≈ 8%, despite 3 wt.% lime + 6 wt.% cement. A decision matrix distilled from these cases and recent literature shows that successful stabilization requires MBV < 3 g/100 g, plastic index < 25%, OM < 7 wt.%, and fine particles < 35%. These thresholds permit rapid screening of dredged lots before costly treatment. Highlighting both positive and negative evidence clarifies the realistic performance envelope of soil–cement reuse and supports circular-economy management of DS.

• Safhi, Amine el Mahdi; Aliyari, Mostafa; Pilehvar, Shima; Nehdi, Moncef & Kioumarsi, Mahdi (2025). Systematic data-driven meta-analysis of class F fly-ash geopolymer concrete. Open Ceramics. 24. doi: 10.1016/j.oceram.2025.100861. Full text in Research Archive Show summary

  Geometry-dependent strength reporting has hindered reliable design of Class F fly-ash geopolymer concrete (FA-GPC). In this study, compressive-strength (CS) results from about 800 mixtures were normalized to the reference 150Ø300 mm cylinder, permitting direct cross-comparison of specimen geometries extracted from 67 peer-reviewed papers. The harmonized dataset bundles oxide chemistry, mix proportions, activator composition, curing schedules, fresh-state metrics, multi-age strengths, and cradle-to-gate CO₂ inventories. Normalized CS across 1–365 days spans 5.8–85.0 MPa, and CO₂ intensities range 66–895 kg CO₂/m³ (mean 160 ± 91). Data mining isolates practical activation windows—NaOH 10–12 M, silica modulus 1.5–2.3, curing ≤ 75 °C—that consistently deliver 28-d CS ≥ 50 MPa at ∼160 kg CO₂/m³. Compared to strength-matched OPC concretes, these mixes reduce embodied carbon by ∼45–55 % (median ≈ 50 %). Strength–carbon design maps and the open dataset enable practitioners to target structural classes under explicit CO₂ budgets and provide a reproducible springboard for machine learning-based prediction, life-cycle assessment, and optimization of alkali-activated concretes and geopolymers.

• Safhi, Amine el Mahdi; Pilehvar, Shima & Kioumarsi, Mahdi (2025). Review of advances and challenges in alkali-activated materials from dredged sediments. Open Ceramics. 23. doi: 10.1016/j.oceram.2025.100824. Full text in Research Archive Show summary

  Dredging worldwide generates over 1 billion m³ of sediments annually, creating disposal and environmental challenges. Alkali-activated materials (AAMs) offer a circular pathway by converting dredged sediments (DS) into sustainable binders and aggregates. This review synthesizes 32 studies on DS-based AAMs, detailing sediments chemistry, pretreatment routes, mix-design strategies, performance, and field cases. Calcination or mechanochemical activation elevates DS reactivity, producing binders that achieve 28-day compressive strengths of 15–40 MPa and durable matrices resistant to sulfate, freeze–thaw, and carbonation. Processed DS sands can fully or partially replace natural fine aggregates while maintaining ≥25 MPa concrete strength. AAM matrices immobilize heavy metals, keeping leachate below inert-waste thresholds. Key knowledge gaps remain in standardized mix design, long-term durability, and regulatory acceptance. The review outlines research and policy priorities to scale DS-AAM technologies for low-carbon infrastructure.

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