Nguyen et al. (2026) — Ice-Cooled Ambient-Cured Ultra-High Performance Engineered Geopolymer Composites (I-UHPEGC)

Citation

Huy Hoang Nguyen, Quang-Hiếu Lương, Phuong Hoang Nguyen, Youngsang Kim, Bang Yeon Lee (2026). Ice-cooled ultra-high performance engineered geopolymer composites for ambient temperature curing: Formulation, properties, and microscale investigation. Developments in the Built Environment, 27, 100972.

• DOI: 10.1016/j.dibe.2026.100972
• Atlas layer: extension
• Related Victor Li book chapter: Chapter 9: Green ECC & Chapter 4: Micromechanics-Based Material Design
• Source PDF: primary_data/nguyen-2026-ice-cooled-ultra-high-performance-engineered-geopolymer.pdfIJP09026E_Ice cooled UHPEGC_DIBE.pdf`
• Extracted text: secondary_data/full_texts/nguyen-2026-ice-cooled-ultra-high-performance-engineered-geopolymer_full_text.mdsecondary_data/full_texts/IJP09026E_Ice cooled UHPEGC_DIBE_full_text.md`
• Source note: secondary_data/source_notes/nguyen-2026-ice-cooled-ultra-high-performance-engineered-geopolymer_source_note.mdsecondary_data/source_notes/IJP09026E_Ice cooled UHPEGC_DIBE_source_note.md`

Why this paper matters

Resolves the critical flash-setting ($<30\text{ min}$) and mandatory heat-curing barriers of ultra-high-performance geopolymer composites by replacing 60.5 wt% of the mixing water with crushed ice as a thermodynamic latent heat sink. This cools the initial slurry to 3.4 °C, extending the final setting time by 5.3 times (to 172 min) and enabling ambient-cured I-UHPEGC ($w/b = 0.19$, 1.0–1.5 vol. % PE) to simultaneously achieve an outstanding compressive strength of $142\text{ MPa}$, tensile strength of $10.88\text{ MPa}$, and direct tensile strain capacity of $10.63\text{--}12.36\text{ \%}$ with tight crack widths of $77.0\ \mu\text{m}$, establishing an unprecedented energy performance margin of $PSHE = 9.74\text{--}12.85$.

Main contribution

• Thermodynamic Ice-Cooling Mechanism: Substituted 60.5 wt% mixing water with ice, extending final setting time 5.3-fold (to 172 min in W-V0.5) and eliminating flash-setting without retarders.
• Ambient-Cured Ultra-High Strength and Ultra-High Ductility:
• W-V1.0 (1.0 % PE, water-cured): $f_c = \mathbf{142\text{ MPa}}$, $\sigma_{tu} = \mathbf{8.97\text{ MPa}}$, $\epsilon_{ts} = \mathbf{10.63 \pm 0.21\text{ \%}}$.
• W-V1.5 (1.5 % PE, water-cured): $f_c = 125\text{ MPa}$, $\sigma_{tu} = \mathbf{10.88\text{ MPa}}$, $\epsilon_{ts} = \mathbf{9.87\text{ \%}}$, 102.7 cracks ($w_c = 77.0\ \mu\text{m}$).
• A-V1.5 (1.5 % PE, air-cured): $f_c = 125\text{ MPa}$, $\sigma_{tu} = \mathbf{10.87\text{ MPa}}$, $\epsilon_{ts} = \mathbf{12.36 \pm 0.20\text{ \%}}$.
• Comprehensive Performance Index ($P_{index}$) Breakthrough: I-UHPEGC outperformed all existing high-performance EGCs by up to 9 times in $P_{index} = f_c \times \epsilon_{tsc} / \omega_c$.
• Micromechanical & Mineralogical Verification: Single fiber pullout confirmed pure frictional slip ($\tau_0 = 0.92\text{--}1.89\text{ MPa}, G_d = 0$) verifying $PSHS = 1.66\text{--}1.71$ and $PSHE = 9.74\text{--}12.85 \gg 2.7$; EDS confirmed dominant C-(N)-A-S-H gel precipitation.

Evidence summary

• Flowability & Setting Time:
• W-V0.5: Flow $180.5\text{ mm}$, Initial setting $130\text{ min}$, Final setting $172\text{ min}$ (Figs. 6–7, Page 5).
• Compressive Strength:
• 28-day $f_c$: W-V0.5 ($140\text{ MPa}$), W-V1.0 ($142\text{ MPa}$), W-V1.5 ($125\text{ MPa}$), A-V1.5 ($125\text{ MPa}$), H-V1.5 ($128\text{ MPa}$) (Figs. 8–9, Pages 5–6).
• Direct Uniaxial Tensile Properties & Cracking:
• W-V1.0: $\sigma_{1c} = 5.07\text{ MPa}$, $\sigma_{tu} = \mathbf{8.97\text{ MPa}}$, $\epsilon_{ts} = \mathbf{10.63 \pm 0.21\text{ \%}}$, 60.5 cracks, $w_c = 140.7\ \mu\text{m}$ (Table 4, 5 & Figs. 10–11, Pages 6–7).
• W-V1.5: $\sigma_{1c} = 6.43\text{ MPa}$, $\sigma_{tu} = \mathbf{10.88\text{ MPa}}$, $\epsilon_{ts} = \mathbf{9.87 \pm 0.44\text{ \%}}$, 102.7 cracks ($w_c = \mathbf{77.0\ \mu\text{m}}, l_s = 0.78\text{ mm}$).
• A-V1.5: $\sigma_{1c} = 6.57\text{ MPa}$, $\sigma_{tu} = \mathbf{10.87\text{ MPa}}$, $\epsilon_{ts} = \mathbf{12.36 \pm 0.20\text{ \%}}$, 76.8 cracks, $w_c = 129.6\ \mu\text{m}$.
• H-V1.5: $\sigma_{1c} = 6.44\text{ MPa}$, $\sigma_{tu} = 11.05\text{ MPa}$, $\epsilon_{ts} = 11.40 \pm 0.34\text{ \%}$.
• Micromechanical PSH Properties:
• $\tau_0 = 1.89\text{ MPa}$ (W-V1.5), $0.92\text{ MPa}$ (A-V1.5), $0.98\text{ MPa}$ (H-V1.5); $K_m = 0.70\text{--}0.78\text{ MPa}\cdot\text{m}^{1/2}$; $PSHS = 1.66\text{--}1.71, PSHE = 9.74\text{--}\mathbf{12.85}$ (Table 6 & Figs. 14–15, Pages 8–9).
• Microstructure: Complete fiber pullout without rupture observed in SEM (Fig. 17, Page 10); EDS confirmed C-(N)-A-S-H gel (Fig. 18, Page 10).

Linked Atlas nodes

• 04_material_systems/cementless_composites.md
• 04_material_systems/high_strength_ecc.md
• 02_concepts/flaw_design.md
• 02_concepts/strain_hardening_criteria.md
• 05_experiments/direct_tensile_test.md

Relationship to Victor Li book

• Primary book anchor remains Victor Li (2019), Engineered Cementitious Composites (ECC).
• Directly extends Chapter 9 (Green ECC) and Chapter 4 (Micromechanics) by employing ice-cooling reaction control to eliminate heat-curing, achieving ambient-cured composites with $142\text{ MPa}$ compressive strength, $10.88\text{ MPa}$ direct tensile strength, $12.36\text{ \%}$ tensile strain capacity, and $77.0\ \mu\text{m}$ crack control ($PSHE = 12.85$).

Claim-evidence rows to add

Verification status

• PDF preserved: yes (in primary_data/IJP09026E_Ice cooled UHPEGC_DIBE.pdf)
• Text extracted: yes (PyMuPDF, 12 pages)
• DOI verified: yes (10.1016/j.dibe.2026.100972)
• Page/figure/table verified: yes (all checked in PDF text)
• Claim-evidence matrix ready: yes

Cautions

• Mixing ice requires sufficient high shear to ensure complete melting before casting.
• Increasing fiber dosage from 1.0 % to 1.5 % slightly decreases compressive strength ($142\rightarrow 125\text{ MPa}$) due to mixing void entrapment.