Choi & Lee (2014) — Properties of Low-Viscosity and High-Ductility Cementless Fiber-Reinforced Composites
Citation
Choi, J.-I., & Lee, B. Y. (2014). Properties of Low-Viscosity and High-Ductility Cementless Fiber-Reinforced Composites. Journal of the Regional Association of Architectural Institute of Korea, 16(4), 115–124.
- DOI:
needs_check(KCI Indexed Journal) - Atlas layer: extension
- Related Victor Li book chapter: Chapter 3: Fiber/Matrix Interfacial Micromechanics & Chapter 9: Green ECC (Alkali-Activated Binders) & Chapter 11: Special Applications (Injectable Grouting & Structural Repair)
- Source PDF:
choi-2014-properties-of-low-viscosity-and-high-ductility.pdf - Extracted text:
full_text/choi-2014-properties-of-low-viscosity-and-high-ductility_full_text.md - Source note:
source_notes/choi-2014-properties-of-low-viscosity-and-high-ductility_source_note.md
Why this paper matters
Solves the rheological bottleneck of standard ECC (which requires high matrix viscosity $\ge 7\text{ Pa}\cdot\text{s}$ for fiber dispersion) by developing an injectable, low-viscosity ($\mu < 1\text{ Pa}\cdot\text{s}$), low-yield-stress ($\tau_0 < 25\text{ Pa}$) cementless composite utilizing alkali-activated slag and 1.3 vol. % PVA fibers, achieving direct tensile strain capacity $> 1.5\%$.
Main contribution
- Formulates a low-viscosity, high-ductility cementless composite tailored for grouting, borehole injection, and congested structural repair applications.
- Develops an indirect rheology calibration framework correlating V-funnel discharge time and mini-slump flow with plastic viscosity and yield stress for fiber-suspended slurries.
- Identifies optimal mixture proportioning ($w/b = 0.40$, 1.3 vol. % oiled PVA fibers, high-range water reducer) to maintain low viscosity ($\le 1\text{ Pa}\cdot\text{s}$) while avoiding fiber balling.
- Verifies hardened mechanical properties: achieves 28-day compressive strength of 18–25 MPa and direct uniaxial tensile strain capacity of 1.5–1.8 % with multiple micro-cracking.
Evidence summary
- Binder & Activator: 100 % Ground Granulated Blast Furnace Slag (GGBS) activated with $\text{Ca(OH)}_2$ (7.5 wt%) and $\text{Na}_2\text{SiO}_3$ (5.0 wt%).
- Water/Binder Ratio: $w/b = 0.40$ (elevated compared to standard ECC 0.25 to lower plastic viscosity).
- Fiber Parameters: 1.3 vol. % Kuraray REC15 PVA fibers ($l_f = 6\text{--}12\text{ mm}$, $d_f = 40\ \mu\text{m}$, oil-coated).
- Rheological Performance:
- Plastic viscosity: $< 1.0\text{ Pa}\cdot\text{s}$ (calibrated via V-funnel time).
- Yield stress: $< 25\text{ Pa}$ (calibrated via mini-slump spread $> 250\text{ mm}$).
- Mechanical Properties:
- 28-day compressive strength: 18.5–24.8 MPa.
- Direct uniaxial tensile strain capacity: $1.52\text{--}1.78\%$.
- First-crack tensile strength: 1.6–2.0 MPa; Ultimate tensile strength: 2.3–2.8 MPa.
Linked Atlas nodes
02_concepts/strain_hardening_criteria.md04_material_systems/green_ecc.md04_material_systems/pva_ecc.md05_experiments/direct_tensile_test.md05_experiments/rheology_testing.md
Relationship to Victor Li book
- Extends Victor Li (2019) Chapter 3 (Fiber/Matrix Interface & Dispersion) and Chapter 11 (Repair Applications) by breaking the trade-off between low grout viscosity and fiber dispersion.
- Demonstrates that micromechanically tailored alkali-activated slag systems can retain pseudo strain-hardening even at reduced fiber volumes (1.3 vol. %) and high fluidity ($w/b = 0.40$).
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
05_experiments/rheology_testing.md |
V-funnel and mini-slump tests reliably approximate plastic viscosity (< 1 Pa·s) and yield stress (< 25 Pa) in fiber-reinforced slurries | Derived empirical calibration curves linking V-funnel time to plastic viscosity and mini-slump to Bingham yield stress | Section 3, Fig. 1-3, Eq. (1)-(4) | verified_from_pdf |
04_material_systems/green_ecc.md |
Alkali-activated slag composite with $w/b = 0.40$ and 1.3 vol. % PVA fibers achieves tensile strain capacity > 1.5 % with low viscosity | Measured direct tensile strain capacity reached 1.52–1.78 % with plastic viscosity < 1.0 Pa·s and $f_c > 18\text{ MPa}$ | Section 4 & 5, Fig. 7-9, Table 5 | verified_from_pdf |
Verification status
- PDF preserved: yes (
choi-2014-properties-of-low-viscosity-and-high-ductility.pdf) - Text extracted: yes (
full_text/choi-2014-properties-of-low-viscosity-and-high-ductility_full_text.md) - DOI verified: N/A (KCI: Journal of the Regional Association of Architectural Institute of Korea)
- Metadata verified: yes (AIK-RA, Vol. 16, No. 4, pp. 115–124, 2014)
- Claim-evidence matrix ready: yes
Cautions
- Designed specifically for low-viscosity injection/grouting; tensile strain capacity (1.5–1.8 %) is slightly lower than standard 2.0 vol. % PVA-ECC (2–4 %) due to lower fiber volume fraction.
- Slag activation kinetics must be controlled to prevent flash setting during pumping.