Zhu et al. (2023) — Preparation and mechanical characterization of cost-effective low-carbon...

Citation

Mingzheng Zhu, Bing Chen, Meng Wu, Jiaxing Han (2023). Preparation and mechanical characterization of cost-effective low-carbon engineered cementitious composites with seawater and sea-sand. Cement and Concrete Composites, Vol. 136, Article 104883.

DOI: 10.1016/j.cemconcomp.2022.104883
Atlas layer: extension
Related Victor Li book chapter: Chapter 4: Special ECCs / Marine Infrastructure; Chapter 8: Life Cycle Assessment and Sustainability
Source PDF: zhu-2023-preparation-and-mechanical-characterization-of.pdf
Extracted text: atlas/full_text/zhu-2023-preparation-and-mechanical-characterization-of_full_text.md
Source note: atlas/source_notes/zhu-2023-preparation-and-mechanical-characterization-of_source_note.md

Why this paper matters

Develops low-carbon, cost-effective seawater sea-sand ECC (SS-ECC) replacing 80% of Portland cement with industrial waste residue (60% fly ash + 20% silica fume), using untreated marine resources and domestic PVA/basalt hybrid fibers, achieving 53.4 MPa compressive strength, 3.75 MPa tensile strength, 3.79% tensile strain capacity, and ultra-tight crack widths (<30 µm).

Main contribution

Successfully integrated 100% seawater and unwashed natural sea-sand with 80% SCM binder (FA + SF).
Evaluated sea-sand particle size thresholds ($0.1\text{--}0.3\text{ mm}$ vs $0.3\text{--}0.5\text{ mm}$ vs $0.6\text{--}1.0\text{ mm}$), finding fine sand essential for multiple cracking.
Hybridized domestic PVA with 6 mm and 12 mm basalt (BA) fibers, revealing that 12 mm BA fibers increase first cracking strength and flexural toughness ($Q_m$).

Evidence summary

Compressive strength: 28d $f_c = 53.4\text{ MPa}$, 60d $f_c = 63.9\text{ MPa}$ in S-S1 baseline (Table 4, Section 4.1, Fig. 7).
Direct tensile properties:
S-S1 (0.1–0.3 mm SD, 2.0% PVA): $\sigma_{fs} = 2.48\text{ MPa}$, $\sigma_{tu} = 3.75\text{ MPa}$, $\varepsilon_{tu} = 3.79\%$, crack width $<30\ \mu\text{m}$ (Figs. 12, 13a, 15).
Coarse sea-sand (0.6–1.0 mm, S-S3): $\varepsilon_{tu}$ drops to $1.52\%$.
12 mm Basalt hybrid (SB12-0.1-S1 to SB12-0.3-S1): $\sigma_{fs}$ increased up to $3.47\text{ MPa}$, $\varepsilon_{tu} = 1.52\text{--}2.73\%$ (Fig. 13c).
Flexural performance: S-S1 reached $15.8\text{ MPa}$ flexural strength at 28d; 12 mm BA fibers increased ultimate 4-point bending deflection up to $3.80\text{ mm}$ (Table 5, Figs. 8, 10).

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`	Cost-effective SS-ECC with 80% clinker replacement by FA and SF achieves 53.4 MPa compressive strength, 3.75 MPa tensile strength, and 3.79% tensile strain capacity with crack widths <30 µm.	Uniaxial compression and dogbone direct tensile tests verified 53.4 MPa compressive strength and 3.79% strain capacity.	Pages 1, 4, 8, 9, Section 4.1, 4.5 & Abstract, Table 4, Figs. 7, 13a, 15	verified_from_pdf
`02_concepts/strain_hardening_criteria.md`	Increasing sea-sand particle size above 0.3 mm degrades tensile ductility by up to 60%, while hybridizing 12 mm basalt fibers improves first-cracking strength and flexural energy dissipation.	Tensile and 4-point bending characterization verified the particle size effect and basalt fiber toughening.	Pages 1, 7, 8, Section 4.4, 4.5 & Abstract, Figs. 10, 11c, 13a, Table 5	verified_from_pdf

Verification status

PDF preserved: yes (zhu-2023-preparation-and-mechanical-characterization-of.pdf)
Text extracted: yes (atlas/full_text/zhu-2023-preparation-and-mechanical-characterization-of_full_text.md)
DOI verified: yes (10.1016/j.cemconcomp.2022.104883)
Page/figure/table verified: yes
Claim-evidence matrix ready: yes

Cautions

Coarse sea-sand containing seashells degrades fiber dispersion and reduces tensile strain capacity.