Keshta et al. (2025) — A Comparative Study of the Behavior of Engineered Cementitious Composites and Engineered Geopolymer Composites Containing Metakaolin and Magnetized Water

Citation

Keshta, M. M., Eltawil, K. A., Elshikh, M. M. Y., & Youssf, O. (2025). A comparative study of the behavior of engineered cementitious composites and engineered geopolymer composites containing metakaolin and magnetized water. Innovative Infrastructure Solutions, 10(1), 6.

DOI: 10.1007/s41062-024-01802-0
Atlas layer: extension
Related Victor Li book chapter: Chapter 9: Green ECC (Comparative Benchmark of ECC vs. EGC) & Chapter 10: Long-Term Marine Durability
Source PDF: keshta-2025-a-comparative-study-of-the.pdf
Extracted text: full_text/keshta-2025-a-comparative-study-of-the_full_text.md
Source note: source_notes/keshta-2025-a-comparative-study-of-the_source_note.md

Why this paper matters

Provides a direct side-by-side comparison of 14 cement-based (ECC) and alkali-activated geopolymer (EGC) mixtures incorporating metakaolin (up to 80 %) and magnetized water, demonstrating that EGC achieves up to 7.3 times higher slump flow, up to 90 % higher compressive strength, and gains 16 % strength under seawater curing compared to cementitious ECC.

Main contribution

Conducts a comprehensive comparative evaluation across 14 companion mixtures (7 ECC vs. 7 EGC) with metakaolin substitutions (0 %, 20 %, 40 %, 60 %, 80 % by volume) and magnetized water (MW).
Evaluates fresh properties, compressive strength, flexural strength, water absorption, sorptivity, and microstructural SEM/EDX mapping.
Investigates tap water versus raw seawater curing regimes on mechanical development over 28 and 90 days.
Discovers that magnetized water breaks hydrogen bond clusters, accelerating aluminosilicate dissolution and boosting compressive strength by 15–25 %.
Reveals that seawater curing increases EGC compressive strength by up to 16 % (activating geopolymer polycondensation), while deteriorating traditional cement-based ECC.

Evidence summary

Binder Formulations:
ECC: OPC + GGBFS (50:50) with Metakaolin (MK) replacing binder at 0 %, 20 %, 40 %, 60 %, 80 % by volume.
EGC: Class F Fly Ash + GGBFS (50:50) activated with liquid $\text{NaOH} + \text{Na}_2\text{SiO}_3$ with identical MK replacement levels.
Water & Fibers: Magnetized water (MW, permanent magnetic field 1.4 Tesla) vs. tap water (TW); 2.0 vol. % PVA fibers ($l_f = 12\text{ mm}, d_f = 40\ \mu\text{m}, \sigma_f = 1600\text{ MPa}$).
Mechanical & Physical Performance (28 days):
Slump flow: EGC exhibited 3.2 to 7.3 times higher slump flow than sticky ECC.
Compressive strength: EGC reached 42.5 to 62.5 MPa, up to 90 % higher than companion ECC mixes (25.4 to 36.8 MPa).
Seawater curing: EGC gained +16 % in compressive strength; ECC exhibited strength loss and surface efflorescence.
Flexural strength: EGC achieved 8.5 to 11.2 MPa with multiple micro-cracking deflection hardening.
Microstructural Observations (SEM/EDX): EGC exhibits low Ca/Si ratios and uniform N-A-S-H / C-A-S-H gel matrices, with magnetized water increasing gel compactness and reducing interfacial micro-porosity.

Linked Atlas nodes

04_material_systems/geopolymer_ecc.md
04_material_systems/green_ecc.md
04_material_systems/pva_ecc.md
05_experiments/flexural_testing.md
02_concepts/circular_economy_materials.md

Relationship to Victor Li book

Extends Victor Li (2019) Chapter 9 (Green ECC) and Chapter 10 (Durability).
Provides quantitative empirical benchmarks directly comparing the physical, mechanical, and marine durability responses of standard Portland cement ECC against geopolymer EGC under identical fiber volume fractions and replacement geometries.

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`04_material_systems/geopolymer_ecc.md`	EGC achieves up to 7.3 times higher slump flow and up to 90 % higher compressive strength than companion cementitious ECC	Direct 14-mix comparative testing of fresh slump flow, ASTM compression, and flexural bending	Section 3.1 & 3.2, Fig. 4-8, Table 4	verified_from_pdf
`04_material_systems/green_ecc.md`	Seawater curing increases compressive strength of slag/FA EGC by up to 16 %, contrasting with strength regression in OPC-ECC	28-day and 90-day comparative water vs seawater curing immersion trials	Section 3.3, Fig. 9 & 10, Table 5	verified_from_pdf

Verification status

PDF preserved: yes (keshta-2025-a-comparative-study-of-the.pdf)
Text extracted: yes (full_text/keshta-2025-a-comparative-study-of-the_full_text.md)
DOI verified: yes (10.1007/s41062-024-01802-0)
Metadata verified: yes (Innov. Infrastruct. Solut., Vol. 10, Art. 6, 2025)
Claim-evidence matrix ready: yes

Cautions

Metakaolin replacement beyond 40 % by volume increases slurry viscosity and requires superplasticizer adjustment to prevent fiber clumping.
Water absorption and sorptivity rates of EGC were slightly higher than dense OPC-ECC, requiring careful mix proportioning for waterproof barrier applications.