Nguyễn et al. (2018) — Self-Healing Properties of Cement-Based and Alkali-Activated Slag-Based Fiber-Reinforced Composites
Citation
Nguyễn, H. H., Choi, J.-I., Song, K.-I., Song, J.-K., Huh, J., & Lee, B. Y. (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: core
- Related Victor Li book chapter: Chapter 4: Pseudo Strain-Hardening Criteria & Chapter 10: Durability and Autogenous Self-Healing (pp. 343–384)
- Source PDF:
nguyen-2018-self-healing-properties-of-cement-based-and.pdf - Extracted text:
full_text/nguyen-2018-self-healing-properties-of-cement-based-and_full_text.md - Source note:
source_notes/nguyen-2018-self-healing-properties-of-cement-based-and_source_note.md
Why this paper matters
The definitive comparative study from Chonnam National University investigating autogenous self-healing in PE-reinforced cementitious ECC vs. alkali-activated slag (AAS) composites, demonstrating that zero-cement slag composites achieve faster physical crack closure (over 90 % width reduction for cracks $< 100\ \mu\text{m}$) via calcium carbonate and hydrotalcite precipitation, while cement composites achieve higher resonant frequency recovery (85 % vs. 60 %).
Main contribution
- Conducts the first direct experimental comparison of self-healing kinetics between OPC-ECC and alkali-activated slag (AAS) composites reinforced with 1.75 vol. % PE fibers ($18\text{ mm}$) at identical $w/b = 0.30$.
- Pre-cracks dogbone specimens under uniaxial tension to 1.5 % strain and subjects them to cyclic water immersion healing regimes for 28 days.
- Evaluates crack closure rates via high-resolution digital optical microscopy and dynamic stiffness recovery via Resonant Frequency (RF) non-destructive testing.
- Demonstrates that slag-based composites achieve superior surface crack sealing (cracks $< 60\ \mu\text{m}$ completely closed; cracks up to $100\ \mu\text{m}$ reduced by $> 90\%$).
- Proves via SEM-EDS that calcium carbonate ($\text{CaCO}_3$) crystals and hydrotalcite-like phases are the primary healing products in both cement and alkali-activated slag matrices.
Evidence summary
- Material Formulations ($w/b = 0.30$):
- Cement-based ECC: Type I OPC, SP, VMA, 1.75 vol. % PE fibers.
- Slag-based Composite (AASC): 100 % GGBFS activated by solid $\text{Ca(OH)}_2$ (11.1 wt% of slag), SP, VMA, 1.75 vol. % PE fibers.
- Fiber Specifications: 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 (Pre-Healing):
- OPC-ECC: $f_c = 58.4\text{ MPa}$, $\sigma_u = 11.8\text{ MPa}$, $\epsilon_u = 6.8\%$.
- Slag-AASC: $f_c = 48.5\text{ MPa}$, $\sigma_u = 8.8\text{ MPa}$, $\epsilon_u = 7.5\%$.
- Self-Healing Quantification:
- Crack Width Closure: Slag-AASC sealed 100 % of cracks $< 60\ \mu\text{m}$ and $> 90\%$ of cracks $60\text{--}100\ \mu\text{m}$, outperforming OPC-ECC in visual closure rate.
- Resonant Frequency Recovery: OPC-ECC recovered 82 % to 88 % of initial dynamic modulus; Slag-AASC recovered 58 % to 64 %.
- Healing Products: SEM-EDS confirmed calcite ($\text{CaCO}_3$) precipitation filling crack gaps in both systems.
Linked Atlas nodes
02_concepts/strain_hardening_criteria.md04_material_systems/geopolymer_ecc.md04_material_systems/green_ecc.md04_material_systems/pe_ecc.md05_experiments/direct_tensile_test.md05_experiments/dynamic_modal_testing.md02_concepts/durability.md
Relationship to Victor Li book
- Extends Victor Li (2019) Chapter 10: Durability and Autogenous Self-Healing (pp. 343–384).
- Validates the tight crack width self-healing threshold ($w_m < 60\ \mu\text{m}$) in cementless slag composites, confirming that eliminating clinker does not impede autogenous mineral precipitation within microcracks.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
02_concepts/durability.md |
Alkali-activated slag PE composites achieve $> 90\%$ crack width closure for microcracks $< 100\ \mu\text{m}$ under water immersion | Microscopic crack width tracking and image analysis over 28 days | Section 3.2, Fig. 5-8, Table 3 | verified_from_pdf |
05_experiments/dynamic_modal_testing.md |
Cement-based ECC achieves higher resonant frequency recovery (85 %) than alkali-activated slag composites (60 %) post-healing | ASTM C215 dynamic resonant frequency recovery monitoring | Section 3.3, Fig. 9 & 10, Table 4 | verified_from_pdf |
Verification status
- PDF preserved: yes (
nguyen-2018-self-healing-properties-of-cement-based-and.pdf) - Text extracted: yes (
full_text/nguyen-2018-self-healing-properties-of-cement-based-and_full_text.md) - DOI verified: yes (
10.1016/j.conbuildmat.2018.01.023) - Metadata verified: yes (CBM, Vol. 165, pp. 801–811, 2018)
- Claim-evidence matrix ready: yes
Cautions
- Cracks wider than $150\ \mu\text{m}$ fail to achieve complete autogenous healing in either system; maintaining tight microcrack widths ($< 60\ \mu\text{m}$) via PSH design is essential.
- Slag-based systems exhibit lower internal resonant frequency recovery than OPC-ECC due to slower C-A-S-H recrystallization compared to continuous Portland hydration.