Lin et al. (2024) — Mechanical properties, micro-mechanisms, and constitutive models of seawater...

Citation

Chenlong Lin, Dongming Huang, Zhenzhen Liu, Yiyan Lu (2024). Mechanical properties, micro-mechanisms, and constitutive models of seawater sea-sand engineered cementitious composites. Journal of Building Engineering, Vol. 94, Article 109987.

DOI: 10.1016/j.jobe.2024.109987
Atlas layer: extension
Related Victor Li book chapter: Chapter 4: Special ECCs / Marine Infrastructure; Chapter 6: Structural Modeling and Analysis
Source PDF: lin-2024-mechanical-properties-micro-mechanisms-and-constitutive.pdf
Extracted text: atlas/full_text/lin-2024-mechanical-properties-micro-mechanisms-and-constitutive_full_text.md
Source note: atlas/source_notes/lin-2024-mechanical-properties-micro-mechanisms-and-constitutive_source_note.md

Why this paper matters

Establishes a practical engineering strength grading framework (C30, C40, C50) for seawater sea-sand ECCs (SS-ECC) reinforced with 2.0 vol% PVA fibers, demonstrating that C40 grade achieves optimal mechanical synergy ($f_{cc} = 44.60\text{ MPa}$, $\sigma_u = 5.20\text{ MPa}$, $\varepsilon_u = 3.42\%$, crack width $<100\ \mu\text{m}$) due to balanced fiber-matrix interfacial friction, and formulates complete non-linear compression and tension constitutive laws.

Main contribution

Designed and characterized three strength-graded SS-ECCs using un-desalinated seawater and extra-fine sea-sand ($0.15\text{--}0.60\text{ mm}$).
Revealed that intermediate strength (C40) maximizes tensile ductility ($\varepsilon_u = 3.42\%$) and strength ($\sigma_u = 5.20\text{ MPa}$), whereas high-strength C50 suffers from fiber rupture ($\varepsilon_u = 1.27\%$).
Formulated validated uniaxial compression (nonlinear ascending + bilinear descending) and tension (bilinear) constitutive models for FE structural analysis.

Evidence summary

Compressive properties: C30 ($f_{cc} = 32.08\text{ MPa}$, $f_{cp} = 27.91\text{ MPa}$), C40 ($f_{cc} = 44.60\text{ MPa}$, $f_{cp} = 36.85\text{ MPa}$), C50 ($f_{cc} = 55.49\text{ MPa}$, $f_{cp} = 44.94\text{ MPa}$) (Table 4, page 9, Fig. 8).
Direct tensile properties:
C40: $\sigma_c = 2.64\text{ MPa}$, $\sigma_u = 5.20 \pm 0.34\text{ MPa}$, $\varepsilon_u = 3.42 \pm 0.17\%$, 45 cracks, average crack width $<100\ \mu\text{m}$.
C30: $\sigma_c = 1.76\text{ MPa}$, $\sigma_u = 3.54\text{ MPa}$, $\varepsilon_u = 2.88 \pm 0.22\%$.
C50: $\sigma_c = 2.76\text{ MPa}$, $\sigma_u = 4.18\text{ MPa}$, $\varepsilon_u = 1.27 \pm 0.22\%$ (Table 6, page 13, Fig. 14).
Constitutive model: Compressive model achieved $R^2 > 0.966$; tensile bilinear model calibrated $E_1 = 9.47\text{--}20.93\text{ GPa}$, $E_2 = 0.063\text{--}0.115\text{ GPa}$ (Table 5, Figs. 13, 14).

Linked Atlas nodes

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/green_ecc.md`	Seawater sea-sand PVA-ECC tailored to C40 grade achieves 44.60 MPa cubic strength, 5.20 MPa tensile strength, and 3.42% tensile ductility with crack widths <100 µm.	Direct tension and compression tests verified 44.60 MPa cubic strength and 3.42% tensile strain capacity.	Pages 1, 9, 13, Section 3.2.2 & Abstract, Tables 4, 6, Figs. 8, 14	verified_from_pdf
`02_concepts/strain_hardening_criteria.md`	Tensile ductility in SS-ECC peaks at intermediate matrix strength (C40) where fiber bridging capacity exceeds cracking stress, whereas high matrix strength (C50) causes premature fiber rupture and reduces ductility to 1.27%.	FE-SEM fracture observation and tensile testing confirmed fiber rupture in C50 vs steady-state pullout in C40.	Pages 10, 12, 14, Section 3.2.2 & 3.2.3, Table 6, Figs. 15, 17	verified_from_pdf

Verification status

PDF preserved: yes (lin-2024-mechanical-properties-micro-mechanisms-and-constitutive.pdf)
Text extracted: yes (atlas/full_text/lin-2024-mechanical-properties-micro-mechanisms-and-constitutive_full_text.md)
DOI verified: yes (10.1016/j.jobe.2024.109987)
Page/figure/table verified: yes
Claim-evidence matrix ready: yes

Cautions

C50 grade SS-ECC exhibits low ductility (1.27%) due to excessive matrix toughness and fiber rupture.