Nguyễn et al. (2018) — Self-Healing of Cement vs Slag-Based PE Composites
Citation
Huy Hoàng Nguyễn, Jeong-Il Choi, Keum-Il Song, Jin-Kyu Song, Jungwon Huh, Bang Yeon Lee (2018). Self-healing properties of cement-based and alkali-activated slag-based fiber-reinforced composites. Construction and Building Materials, 165, 801–811.
- DOI:
10.1016/j.conbuildmat.2018.01.023 - Atlas layer: supporting
- Related Victor Li book chapter: Chapter 8: Self-Healing and Durability of ECC (also Chapter 9)
- Source PDF:
primary_data/nguyen-2018-self-healing-properties-of-cement-based-and.pdfIJP04018E_Self-healing properties_CBM.pdf` - Extracted text:
secondary_data/full_texts/nguyen-2018-self-healing-properties-of-cement-based-and_full_text.mdsecondary_data/full_texts/IJP04018E_Self-healing properties_CBM_full_text.md` - Source note:
secondary_data/source_notes/nguyen-2018-self-healing-properties-of-cement-based-and_source_note.mdsecondary_data/source_notes/IJP04018E_Self-healing properties_CBM_source_note.md`
Why this paper matters
Directly compares the self-healing capacity, stiffness recovery, and tensile strain-hardening of cement-based vs alkali-activated slag-based PE fiber composites ($w/b = 0.30$, 1.75 vol. % PE), confirming a universal ~50 $\mu\text{m}$ crack closure threshold governed by calcium carbonate ($\text{CaCO}_3$) precipitation.
Main contribution
- Universal ~50 $\mu\text{m}$ Self-Healing Threshold: Proved that cracks $\le 50\ \mu\text{m}$ achieve complete physical closure within 36 days of water immersion in both OPC (54.0 $\mu\text{m}$) and alkali-activated slag (55.0 $\mu\text{m}$) composites.
- Superior Ductility in Slag-EGC: Achieved a direct tensile strain capacity of $5.46 \pm 0.22\text{ \%}$ ($\sigma_{tu} = 8.55\text{ MPa}$) in slag composite (S30) vs $2.66 \pm 0.33\text{ \%}$ in cement composite (C30), driven by $\sigma_u/\sigma_{fc} = 4.48$.
- Stiffness Recovery & Crystal Chemistry: Confirmed resonant frequency recovery of 77.8 % in C30 and 64.3 % in S30, with EDS identifying $\text{CaCO}_3$ crystals bridging across PE fibers and matrix walls.
Evidence summary
- Direct Tensile Response: $\epsilon_u = 5.46\text{ \%}$ ($\sigma_{tu} = 8.55\text{ MPa}$) for S30 vs $\epsilon_u = 2.66\text{ \%}$ ($\sigma_{tu} = 8.17\text{ MPa}$) for C30 (Table 3, Page 804).
- Compressive Strength: $86.3\text{ MPa}$ (C30) vs $46.1\text{ MPa}$ (S30) (Table 3, Page 804).
- Self-Healing Closure: 100 % closure for cracks $\le 50\ \mu\text{m}$; residual width for 50–150 $\mu\text{m}$ cracks reduced to 23.4 % (S30) and 25.5 % (C30) (Figs. 5–7, Pages 806–807).
- Resonant Frequency Recovery: 77.8 % (C30) and 64.3 % (S30) after 36 days immersion (Fig. 9, Page 808).
Linked Atlas nodes
02_concepts/self_healing_mechanisms.md04_material_systems/green_ecc.md05_experiments/crack_width_distribution.md02_concepts/strain_hardening_criteria.md05_experiments/direct_tensile_test.md
Relationship to Victor Li book
- Primary book anchor remains Victor Li (2019), Engineered Cementitious Composites (ECC).
- Directly supports Chapter 8 (Self-Healing ECC) and Chapter 9 (Green ECC) by verifying that the $50\ \mu\text{m}$ autogenous healing limit applies equally to sustainable slag-based geopolymers.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
02_concepts/self_healing_mechanisms.md |
Both cement-based and slag-based PE-ECC achieve 100 % autogenous closure for crack widths below ~50 $\mu\text{m}$ | Full healing confirmed for cracks up to 54 $\mu\text{m}$ (C30) and 55 $\mu\text{m}$ (S30) after 36 days in water | Page 801 & 805 / Fig. 5 & 6 | verified_from_pdf |
04_material_systems/green_ecc.md |
Alkali-activated slag PE composite delivers 5.46 % tensile ductility (2x cement ECC) with 8.55 MPa tensile strength | S30 achieved $\epsilon_u = 5.46\text{ \%}$ and $\sigma_{tu} = 8.55\text{ MPa}$ in direct uniaxial tension | Page 804 / Table 3 / Fig. 3 | verified_from_pdf |
02_concepts/self_healing_mechanisms.md |
$\text{CaCO}_3$ crystals precipitate on PE fibers and crack flanks, restoring up to 77.8 % dynamic resonant frequency stiffness | SEM-EDS confirmed $\text{CaCO}_3$ as primary healing phase with 77.8 % RF recovery in C30 | Page 807 & 808 / Table 5 / Fig. 9 | verified_from_pdf |
Verification status
- PDF preserved: yes (in
primary_data/IJP04018E_Self-healing properties_CBM.pdf) - Text extracted: yes (PyMuPDF, 11 pages)
- DOI verified: yes (
10.1016/j.conbuildmat.2018.01.023) - Page/figure/table verified: yes (all checked in PDF text)
- Claim-evidence matrix ready: yes
Cautions
- Slag-based composite showed lower resonant frequency recovery (64.3 % vs 77.8 %) due to larger initial crack width and higher crack count.