Mahmoud et al. (2026) — Performance of Sustainable ECC and EGC in Hybrid Concrete Beams: Experimental Evaluation and Finite Element Validation

Citation

Mahmoud, I. A., Youssf, O., & Nabil, A. (2026). Performance of sustainable ECC and EGC in hybrid concrete beams: experimental evaluation and finite element validation. Innovative Infrastructure Solutions, 11(1), 23.

DOI: 10.1007/s41062-025-02369-0
Atlas layer: core
Related Victor Li book chapter: Chapter 5: Constitutive Modeling & Chapter 9: Green ECC (Mineral Waste Upcycling) & Chapter 10: Structural Applications (Hybrid RC Beams, pp. 343–384)
Source PDF: mahmoud-2026-performance-of-sustainable-ecc-and-egc.pdf
Extracted text: full_text/mahmoud-2026-performance-of-sustainable-ecc-and-egc_full_text.md
Source note: source_notes/mahmoud-2026-performance-of-sustainable-ecc-and-egc_source_note.md

Why this paper matters

Evaluates full-scale hybrid reinforced concrete beams ($150 \times 300 \times 2000\text{ mm}$) incorporating sustainable ECC and EGC tensile replacement layers made with ceramic powder, basalt powder, and metakaolin, proving that ceramic powder EGC layers enhance ultimate load by 14.5 % and ductility by 21 %, validated by 3D ABAQUS finite element modeling.

Main contribution

Fabricates and tests 8 full-scale hybrid RC beams ($150 \times 300 \times 2000\text{ mm}$) incorporating sustainable ECC and EGC layers in the bottom tensile zone under four-point bending.
Formulates green ECC and EGC mixtures incorporating ceramic powder (CP), basalt powder (BP), GGBFS, and metakaolin (MK) as partial cement/precursor substitutes.
Demonstrates that ceramic powder (CP) in EGC layers boosts beam ultimate load capacity by 14.5 % and displacement ductility by 21.0 % over control RC beams.
Demonstrates that metakaolin (MK) in ECC layers increases beam flexural ductility by 24.0 %, while CP boosts initial elastic stiffness by 21.0 %.
Establishes and validates an ABAQUS 3D finite element simulation using Concrete Damaged Plasticity (CDP), performing parametric studies on layer thickness (enhancing capacity by 6.7 %) and reinforcement ratios.

Evidence summary

Beam Geometry & Layers: $150 \times 300 \times 2000\text{ mm}$ (clear span 1800 mm); bottom tension zone (50–100 mm depth) replaced with ECC or EGC.
Mix Formulations:
ECC: OPC + GGBFS + Ceramic Powder (CP) / Basalt Powder (BP) / Metakaolin (MK) + 2.0 vol. % PVA fibers.
EGC: Class F Fly Ash + GGBFS + CP / BP / MK activated with sodium silicate + sodium hydroxide.
Structural Flexural Performance:
Ultimate load ($P_u$): Control RC = 112.5 kN; CP-ECC Beam = 120.4 kN (+7.0 %); CP-EGC Beam = 128.8 kN (+14.5 %).
Ductility index ($\Delta_u/\Delta_{cr}$): CP-ECC (+11.7 %), MK-ECC (+24.0 %), CP-EGC (+21.0 %).
Elastic stiffness: CP-ECC (+21 %), BP-EGC (+10 %), MK-EGC (+9 %).
Crack control: ECC/EGC layers prevented localized tensile flexural cracks, redistributing strain into multiple fine micro-cracks ($< 0.1\text{ mm}$).
FEM Validation (ABAQUS CDP): Strong numerical-experimental correlation with $< 5\%$ error in peak load and stiffness.

Linked Atlas nodes

02_concepts/strain_hardening_criteria.md
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
04_material_systems/link_slab.md

Relationship to Victor Li book

Extends Victor Li (2019) Chapter 5 (Constitutive Modeling), Chapter 9 (Green ECC), and Chapter 10 (Structural Design Guidelines).
Demonstrates the practical structural layering strategy proposed by Victor Li: placing ductile ECC/EGC solely in the critical high-tension cover zone optimizes material efficiency, maximizes structural ductility, and provides significant carbon savings over full-depth composite casting.

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`04_material_systems/link_slab.md`	Replacing the bottom tension zone of RC beams with a ceramic powder EGC layer enhances ultimate load by 14.5 % and ductility by 21 %	Four-point bending tests on 8 full-scale $150 \times 300 \times 2000\text{ mm}$ beams	Section 3.1 & 3.2, Fig. 6-11, Table 4	verified_from_pdf
`04_material_systems/green_ecc.md`	Metakaolin and ceramic powder green ECC/EGC layers increase hybrid beam flexural ductility by 21–24 % and stiffness by up to 21 %	Experimental load-deflection responses and ABAQUS CDP numerical modeling	Section 3.2 & 4.2, Fig. 12-16, Table 5	verified_from_pdf

Verification status

PDF preserved: yes (mahmoud-2026-performance-of-sustainable-ecc-and-egc.pdf)
Text extracted: yes (full_text/mahmoud-2026-performance-of-sustainable-ecc-and-egc_full_text.md)
DOI verified: yes (10.1007/s41062-025-02369-0)
Metadata verified: yes (Innov. Infrastruct. Solut., Vol. 11, Art. 23, 2026)
Claim-evidence matrix ready: yes

Cautions

Omitting longitudinal steel reinforcement in hybrid beams severely reduces load-bearing capacity by 41 % to 60 %; ECC/EGC layers enhance ductility and crack distribution but should work synergistically with steel rebars in primary load-carrying flexural members.
Strong interfacial bonding between conventional concrete and the ECC/EGC layer is essential to avoid horizontal shear slip along the cold joint.