Alemu et al. (2023) — On crack healing in fiber-reinforced cementitious composites...

Citation

Abel Shiferaw Alemu, Jeong-Il Choi, Huy Hoàng Nguyễn, Seongcheol Choi, Jung-Il Suh, Bang Yeon Lee, Hyeong-Ki Kim (2023). On crack healing in fiber-reinforced cementitious composites incorporating mineral-based healing agent and superabsorbent polymer: Evaluation using modified permeability test method. Cement and Concrete Composites, Vol. 141, Article 105111.

DOI: 10.1016/j.cemconcomp.2023.105111
Atlas layer: extension
Related Victor Li book chapter: Chapter 4: Special ECCs; Chapter 7: Self-Healing and Durability
Source PDF: alemu-2023-on-crack-healing-in-fiber-reinforced.pdf
Extracted text: atlas/full_text/alemu-2023-on-crack-healing-in-fiber-reinforced_full_text.md
Source note: atlas/source_notes/alemu-2023-on-crack-healing-in-fiber-reinforced_source_note.md

Why this paper matters

Comprehensive experimental study evaluating autogenous water permeability reduction and crack self-healing kinetics in hybrid PE-PVA fiber ECCs (1.25% PE + 0.1% PVA, achieving 6.2–7.3% tensile strain capacity) under active strain control, demonstrating that fiber bridging and crack-width control govern water tightness recovery over chemical self-healing agents.

Main contribution

Developed a modified constant-head (0.5 m) permeability testing methodology with active strain-controlled jigs for cracked ECC prisms.
Quantified permeability recovery across incremental preloading strains (0.3%, 1%, 2%, 3%), achieving complete water tightness (healed fraction = 1.0) within 6–12 h at $\le 1\%$ strain, and 0.90 healing even at 2–3% strain ($0.58\text{--}0.80\text{ mm}$ crack widths).
Proved that reducing fiber content to 0.5% increased water permeability by 8–30 fold and reduced 28-day self-healing capacity by 64–84%.

Evidence summary

Mechanical properties: Compressive strength $f_c = 45.0\text{--}82.7\text{ MPa}$; tensile strength $\sigma_{tu} = 6.2\text{--}8.5\text{ MPa}$; tensile strain capacity $\varepsilon_{tu} = 4.95\text{--}7.30\%$ (Table 3, page 8).
Water tightness kinetics: 0.3% and 1.0% strain samples achieved 100% sealing in 6–12 h; 2% and 3% strain samples plateaued at 90% sealing in 24–48 h (Fig. 10, page 8).
Decoupled healing drivers: Fiber bridging and crack closure dominate over chemical SHA/SAP admixtures in controlling water permeability (Section 3.2, pages 7-8).

Linked Atlas nodes

04_material_systems/green_ecc.md
02_concepts/extreme_ductility_ecc.md
02_concepts/strain_hardening_criteria.md
05_experiments/direct_tensile_test.md

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`02_concepts/extreme_ductility_ecc.md`	Hybrid PE-PVA (1.25% PE + 0.1% PVA) ECC achieves tensile strain capacities of 6.20–7.30% and compressive strengths up to 82.7 MPa.	JSCE dogbone direct tensile testing verified tensile strain capacities of 6.20% (R1), 6.54% (R2), and 7.30% (R3).	Pages 2, 8, Section 2.1 & 3, Table 3	verified_from_pdf
`05_experiments/direct_tensile_test.md`	In self-healing evaluation, fiber bridging dominates water permeability reduction over chemical healing agents, achieving a 0.90 healed fraction even at 2–3% preloading strain.	Constant-head permeability testing on cracked ECC prisms verified 90% water flow reduction within 24–48 h under 2–3% strain.	Pages 1, 7, Section 3.1 & Abstract, Figs. 10, 18	verified_from_pdf

Verification status

PDF preserved: yes (alemu-2023-on-crack-healing-in-fiber-reinforced.pdf)
Text extracted: yes (atlas/full_text/alemu-2023-on-crack-healing-in-fiber-reinforced_full_text.md)
DOI verified: yes (10.1016/j.cemconcomp.2023.105111)
Page/figure/table verified: yes
Claim-evidence matrix ready: yes

Cautions

SHA incorporation slightly reduces strain capacity (from 7.30% to 4.95%) due to chemical matrix densification around fiber interfaces.