Wen et al. (2024) — High-strength high-ductility seawater sea-sand Engineered Cementitious Composites...

Citation

Shaoyong Wen, Mingli Cao, Guangzhao Liu (2024). High-strength high-ductility seawater sea-sand Engineered Cementitious Composites: Mechanical properties, cracking behavior and micro-mechanics. Journal of Building Engineering, Vol. 90, Article 109404.

DOI: 10.1016/j.jobe.2024.109404
Atlas layer: extension
Related Victor Li book chapter: Chapter 4: Special ECCs / Marine Infrastructure; Chapter 2: Micromechanics and Materials Design
Source PDF: wen-2024-high-strength-high-ductility-seawater-sea-sand-engineered.pdf
Extracted text: atlas/full_text/wen-2024-high-strength-high-ductility-seawater-sea-sand-engineered_full_text.md
Source note: atlas/source_notes/wen-2024-high-strength-high-ductility-seawater-sea-sand-engineered_source_note.md

Why this paper matters

Develops an ultra-high performance seawater sea-sand ECC (SS-ECC) combining 2.0 vol% PE fibers with 0.3 vol% CaCO3 whiskers (CW), achieving 132.7 MPa compressive strength, 7.8 MPa tensile strength, 10.3% tensile strain capacity, and refined average crack width of 64.3 µm by maximizing the energy PSH index ($PSH_{Energy} = 74.32$).

Main contribution

Overcame the strength-ductility trade-off in marine composites, formulating a 132.7 MPa compressive strength SS-ECC with 10.3% tensile strain capacity.
Demonstrated multi-scale bridging synergy: aragonite $CaCO_3$ whiskers bridge microcracks at sub-micron scales while PE fibers bridge macrocracks.
Formulated a modified multi-scale micromechanical PSH model accounting for whisker stiffening and fiber-matrix interfacial friction.
Reduced crack widths to $64.3\ \mu\text{m}$ and lowered unit performance cost to $54.7\text{ \$/m}^3/\text{MPa}$ (50% cheaper per MPa than conventional HS-ECC).

Evidence summary

Compressive strength: CW-0 ($124.3\text{ MPa}$), CW-0.3 ($132.7\text{ MPa}$), CW-0.5 ($138.2\text{ MPa}$), CW-0.8 ($144.5\text{ MPa}$) (Section 3.1, Fig. 4, Table 8).
Direct tensile properties:
CW-0.3: $\sigma_t = 7.8\text{ MPa}$, $\varepsilon_{tu} = 10.3\%$, mean crack width $64.3\ \mu\text{m}$, $PSH_{Strength} = 2.11$, $PSH_{Energy} = 74.32$.
CW-0: $\sigma_t = 7.0\text{ MPa}$, $\varepsilon_{tu} = 5.9\%$, crack width $91.5\ \mu\text{m}$.
CW-0.8: $\sigma_t = 8.7\text{ MPa}$, $\varepsilon_{tu} = 3.6\%$, crack width $106.9\ \mu\text{m}$ (Table 4, 7, 8, Figs. 5, 6).
Micromechanics: Complementary energy reached $J'_b = 1054.55\text{ J/m}^2$ in CW-0.3 with single-fiber interfacial stress $\tau = 1.738\text{ MPa}$ (Tables 5, 7, Fig. 13).

Linked Atlas nodes

04_material_systems/high_strength_ecc.md
02_concepts/extreme_ductility_ecc.md
04_material_systems/green_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
`04_material_systems/high_strength_ecc.md`	Hybrid reinforcement with 2.0 vol% PE fibers and 0.3 vol% CaCO3 whiskers (CW-0.3) in seawater sea-sand ECC achieves 132.7 MPa compressive strength, 7.8 MPa tensile strength, and 10.3% tensile ductility.	ASTM C109 compressive testing and JSCE direct tensile tests verified 132.7 MPa strength and 10.3% ductility.	Pages 1, 6, 13, Section 3.2.1, 6 & Abstract, Table 8, Figs. 4, 5b, 6	verified_from_pdf
`02_concepts/strain_hardening_criteria.md`	Adding 0.3 vol% CW refines mean crack width to 64.3 µm and maximizes complementary energy to J'b = 1054.55 J/m², yielding a peak energy PSH index of 74.32, whereas excessive CW (0.8 vol%) elevates fiber fracture to 24.2% and drops ductility to 3.6%.	Single crack bridging tests and modified PSH modeling verified J'b and PSHEnergy maximization.	Pages 1, 7, 10, 11, Section 4.2, 5.3 & Abstract, Tables 4, 7, Figs. 10, 14, 15	verified_from_pdf

Verification status

PDF preserved: yes (wen-2024-high-strength-high-ductility-seawater-sea-sand-engineered.pdf)
Text extracted: yes (atlas/full_text/wen-2024-high-strength-high-ductility-seawater-sea-sand-engineered_full_text.md)
DOI verified: yes (10.1016/j.jobe.2024.109404)
Page/figure/table verified: yes
Claim-evidence matrix ready: yes

Cautions

Excessive CW dosage ($>0.5\text{ vol\%}$) over-densifies matrix, raising fiber fracture to 24.2% and reducing tensile ductility to 3.6%.