Nguyễn et al. (2023) — Taguchi Optimization of Lightweight Fly Ash ECFC with 11.0% Ductility

Citation

Phương Hoàng Nguyễn, Huy Hoàng Nguyễn, Quang-Hiếu Lương, John E. Bolander, Bang Yeon Lee (2023). Optimization of fly ash-based polyethylene fiber-reinforced engineered cement-free composites with low-density and ultra-ductility using Taguchi robust design method. Journal of Building Engineering, 66, 105946.

• DOI: 10.1016/j.jobe.2023.105946
• Atlas layer: extension
• Related Victor Li book chapter: Chapter 9: Green ECC (also Chapter 4)
• Source PDF: primary_data/nguyen-2023-optimization-of-fly-ash-based-polyethylene.pdfIJP07223E_Optimization of FEGC_JBE.pdf`
• Extracted text: secondary_data/full_texts/nguyen-2023-optimization-of-fly-ash-based-polyethylene_full_text.mdsecondary_data/full_texts/IJP07223E_Optimization of FEGC_JBE_full_text.md`
• Source note: secondary_data/source_notes/nguyen-2023-optimization-of-fly-ash-based-polyethylene_source_note.mdsecondary_data/source_notes/IJP07223E_Optimization of FEGC_JBE_source_note.md`

Why this paper matters

Optimizes fly ash-based engineered cement-free composites (F-ECFC, $w/b = 0.345$, PE fiber 0.5–2.0 vol. %) across curing temperature ($60\text{--}120\ ^\circ\text{C}$), duration (12–48 h), and fiber volume using the Taguchi robust design method ($L_{16}$ orthogonal array) and ANOVA/multiple regression. Develops an optimized lightweight structural composite (80°C-48H-2%) with a density of $1.62\text{ g/cm}^3$, compressive strength of 25.9 MPa, tensile strength of 8.28 MPa, direct tensile strain capacity of 11.0 %, and 60.6 % lower carbon footprint vs M45 ECC.

Main contribution

• Taguchi L16 & ANOVA Optimization: Mapped the complex interactions of curing temperature, duration, and fiber fraction across 16 factorial combinations; ANOVA proved curing temperature governs compressive strength (77.3 % contribution) while fiber volume governs tensile strength (78.9 % contribution).
• Mathematical Closed-Form Regression Models: Derived predictive regression equations (Eqs. 14–18) for density, compressive strength, first-cracking strength, tensile strength, and tensile strain capacity, predicting the optimal mix within $<7\text{ \%}$ error.
• Optimized Lightweight & Ultra-Ductile Material: Validated the 80°C-48H-2% mix delivering a density of $1.62\text{ g/cm}^3$, compressive strength of $25.9\text{ MPa}$, tensile strength of $8.28\text{ MPa}$, and direct tensile strain capacity of $11.0\text{ \%}$.
• 60.6 % Carbon Footprint Reduction: Quantified life cycle sustainability via MSI, showing a 60.6 % reduction in carbon footprint compared to traditional M45 PVA-ECC.

Evidence summary

• L16 Parametric Range:
• Density: $\rho_h = 1.55\text{--}1.78\text{ g/cm}^3$ (all $< 1.92\text{ g/cm}^3$, lightweight).
• Compressive Strength: $f_c = 0.34\text{--}32.51\text{ MPa}$ (Table 6, Page 6).
• Direct Tensile Strength: $f_{ts} = 0.38\text{--}8.79\text{ MPa}$ (Table 7, Page 9).
• Direct Tensile Strain Capacity: $\epsilon_{ts} = 0.74\text{--}\mathbf{14.65\text{ \%}}$ (60°C-24H-1.0% reached 14.65 %).
• Optimized 80°C-48H-2% Mixture:
• Experimental: $\rho_h = 1.62\text{ g/cm}^3$, $f_c = 25.9\text{ MPa}$, $\sigma_{tu} = 8.28\text{ MPa}$, $\epsilon_{ts} = \mathbf{11.0\text{ \%}}$ (Table 14 & Fig. 5, Page 13).
• Model Predicted: $\rho_h = 1.66\text{ g/cm}^3$, $f_c = 20.4\text{ MPa}$, $\sigma_{tu} = 8.60\text{ MPa}$, $\epsilon_{ts} = 10.2\text{ \%}$ (Error: 3.9 % on $f_{ts}$, 7.0 % on $\epsilon_{ts}$).
• MSI Sustainability: Carbon footprint $355\text{ kg/m}^3$ (-60.6 % vs M45-ECC), Embodied energy $7320\text{ MJ/m}^3$ (-18.5 % vs M45-ECC) (Table 15 & Fig. 7, Pages 13–15).

Linked Atlas nodes

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

Relationship to Victor Li book

• Primary book anchor remains Victor Li (2019), Engineered Cementitious Composites (ECC).
• Directly extends Chapter 9 (Green ECC, Section 9.5) and Chapter 4 by establishing a mathematical Taguchi regression model that optimizes curing conditions and fiber fractions to achieve a structural lightweight geopolymer composite ($\rho = 1.62\text{ g/cm}^3$, $f_c = 25.9\text{ MPa}$, $\epsilon_{ts} = 11.0\text{ \%}$) with 60.6 % carbon footprint reduction.

Claim-evidence rows to add

Verification status

• PDF preserved: yes (in primary_data/IJP07223E_Optimization of FEGC_JBE.pdf)
• Text extracted: yes (PyMuPDF, 17 pages)
• DOI verified: yes (10.1016/j.jobe.2023.105946)
• Page/figure/table verified: yes (all checked in PDF text)
• Claim-evidence matrix ready: yes

Cautions

• Elevated temperature curing ($80\ ^\circ\text{C}$ for 48 h) is necessary for structural-grade strength ($25.9\text{ MPa}$).
• Raw material cost ($1020\text{ \$/m}^3$) is higher than PVA-ECC due to PE fiber pricing.