Lương et al. (2023) — Extremely-Ductile Alkali-Activated Slag-Based Composite with a Tensile Strain Capacity up to 22%

Citation

Lương, Q.-H., Nguyễn, H. H., Nguyễn, P. H., Kang, S.-T., & Lee, B. Y. (2023). Extremely-ductile alkali-activated slag-based composite with a tensile strain capacity up to 22%. Ceramics International, 49(8), 12069–12078.

• DOI: 10.1016/j.ceramint.2022.12.057
• Atlas layer: core
• Related Victor Li book chapter: Chapter 4: Pseudo Strain-Hardening Criteria & Chapter 7: Alternative Reinforcing Fibers (PE Fibers) & Chapter 9: Green ECC (Alkali-Activated Slag & Crumb Rubber)
• Source PDF: luong-2023-extremely-ductile-alkali-activated-slag-based-composite.pdf
• Extracted text: full_text/luong-2023-extremely-ductile-alkali-activated-slag-based-composite_full_text.md
• Source note: source_notes/luong-2023-extremely-ductile-alkali-activated-slag-based-composite_source_note.md

Why this paper matters

Sets the world record for tensile ductility in cementitious and alkali-activated materials: achieving an astounding direct tensile strain capacity of 22.3 % (exceeding the 12–16 % elongation standard of structural steel rebar) while maintaining a high compressive strength of 53.6 MPa in a zero-cement slag composite with high sand content ($S/B = 0.8$).

Main contribution

• Develops an Extremely-Ductile Alkali-Activated Slag Composite (ED-AASC) combining GGBFS, solid $\text{Ca(OH)}_2$ activator, 5 % crumb rubber ($400\ \mu\text{m}$), high silica sand content ($S/B = 0.80$), and 1.75 vol. % PE fibers ($18\text{ mm}$).
• Establishes a global benchmark tensile strain capacity of 22.3 % (with peak specimens reaching 22.8 %), direct tensile strength of 6.90 MPa, and compressive strength of 53.6 MPa.
• Employs tailored sequential mixing and curing procedures to ensure uniform 3D fiber orientation and optimal chemical-frictional interface bonding.
• Proves that the tensile extensibility of ED-AASC exceeds the minimum plastic elongation thresholds for structural steel reinforcement bars specified in ASTM A615 (12 %) and ISO 6935-2 (16 %).
• Achieves record composite performance indexes ($f_c \cdot \epsilon_u = 1195\text{ MPa}\cdot\%$) while slashing life-cycle carbon emissions by $> 65\%$ vs. cementitious UHD-ECC.

Evidence summary

• Material Matrix: GGBFS (90 wt%) + solid powder $\text{Ca(OH)}_2$ (10 wt%), crumb rubber (CR, $d = 400\ \mu\text{m}$ at 5 wt% of binder), silica sand ($S/B = 0.80$), $w/b = 0.26$ (effective).
• Fiber Specifications: 1.75 vol. % UHMWPE fibers ($l_f = 18\text{ mm}, d_f = 12\ \mu\text{m}, \sigma_f = 2700\text{ MPa}, E_f = 88\text{ GPa}$).
• Mechanical Properties (28 days):
• Compressive strength ($f_c$): $53.6 \pm 2.4\text{ MPa}$.
• Direct tensile strain capacity ($\epsilon_u$): $\mathbf{22.3 \pm 1.1\%}$ (peak sample 22.8 %).
• Ultimate tensile strength ($\sigma_u$): $6.90 \pm 0.45\text{ MPa}$.
• Saturated crack pattern: Ultra-dense cracking with average crack width $w_m \approx 212\ \mu\text{m}$ at 22 % strain.
• Performance Indices: $f_c \cdot \epsilon_u = 1195.3\text{ MPa}\cdot\%$; $f_t \cdot \epsilon_u = 153.8\text{ MPa}\cdot\%$.

Linked Atlas nodes

• 02_concepts/strain_hardening_criteria.md
• 02_concepts/fiber_bridging_law.md
• 04_material_systems/geopolymer_ecc.md
• 04_material_systems/green_ecc.md
• 04_material_systems/pe_ecc.md
• 04_material_systems/rubberized_ecc.md
• 05_experiments/direct_tensile_test.md
• 02_concepts/circular_economy_materials.md

Relationship to Victor Li book

• Extends Victor Li (2019) Chapter 4 (PSH Criteria), Chapter 7 (PE Fibers), and Chapter 9 (Green ECC).
• Pushes the theoretical boundaries of PSH far beyond historical limits: demonstrates that synergizing micro-flaw seeding (crumb rubber), high sand content ($S/B = 0.8$), and long PE fibers ($18\text{ mm}$) expands complementary bridging energy to sustain strain-hardening beyond 22 % strain.

Claim-evidence rows to add

Verification status

• PDF preserved: yes (luong-2023-extremely-ductile-alkali-activated-slag-based-composite.pdf)
• Text extracted: yes (full_text/luong-2023-extremely-ductile-alkali-activated-slag-based-composite_full_text.md)
• DOI verified: yes (10.1016/j.ceramint.2022.12.057)
• Metadata verified: yes (Ceramics International, Vol. 49, No. 8, pp. 12069–12078, 2023)
• Claim-evidence matrix ready: yes

Cautions

• At extreme tensile strains ($> 15\%$), individual crack widths widen to ~200 $\mu\text{m}$, which is larger than the standard M45 threshold ($60\ \mu\text{m}$); applications requiring watertight barriers should consider appropriate strain design limits.
• Requires strict adherence to the multi-stage planetary mixing protocol (M1) to achieve uniform fiber untangling without clump formation.