Nematollahi et al. (2017) — High Ductile Behavior of a Polyethylene Fiber-Reinforced One-Part Geopolymer Composite: A Micromechanics-Based Investigation

Citation

Nematollahi, B., Sanjayan, J., Qiu, J., & Yang, E.-H. (2017). High ductile behavior of a polyethylene fiber-reinforced one-part geopolymer composite: A micromechanics-based investigation. Archives of Civil and Mechanical Engineering, 17(3), 555–563.

DOI: 10.1016/j.acme.2016.12.005
Atlas layer: core
Related Victor Li book chapter: Chapter 4: Pseudo Strain-Hardening Criteria & Chapter 7: Alternative Reinforcing Fibers (PE vs. PVA Interface Mechanics) & Chapter 9: Green ECC (One-Part "Just-Add-Water" Geopolymers, pp. 307–342)
Source PDF: nematollahi-2017-one-part-shgc-pe-fiber-micromechanics.pdf
Extracted text: full_text/nematollahi-2017-one-part-shgc-pe-fiber-micromechanics_full_text.md
Source note: source_notes/nematollahi-2017-one-part-shgc-pe-fiber-micromechanics_source_note.md

Why this paper matters

A landmark micromechanics study from Swinburne University and NTU Singapore developing ambient-cured "just-add-water" dry-mix one-part strain-hardening geopolymer composites (One-Part PE-SHGC), achieving 4.8 % ambient tensile ductility ($\sigma_u = 5.1\text{ MPa}$, $f_c = 42.5\text{ MPa}$) by tailoring single-fiber slip-hardening pullout kinetics ($\tau_0 = 1.62\text{--}2.24\text{ MPa}$) and eliminating user-hostile liquid activators and heat curing.

Main contribution

Develops an ambient-cured "just-add-water" dry-mix One-Part Strain-Hardening Geopolymer Composite (One-Part SHGC / EGC) combining fly ash, slag, micro-silica sand, dry solid activators, and 2.0 vol. % UHMWPE fibers.
Eliminates the two main commercial barriers of geopolymer composites: corrosive liquid alkaline activators and the necessity of high-temperature heat curing.
Performs multi-scale micromechanical characterization linking single-fiber pullout tests ($\tau_0, G_d, \beta$), SENB matrix fracture toughness ($K_m, J_{tip}$), theoretical $\sigma(\delta)$ fiber bridging laws, and macroscopic direct uniaxial tensile responses.
Discovers that PE fibers exhibit stable slip-hardening pullout ($\beta > 0$) without fiber rupture in one-part geopolymer paste, whereas PVA fibers suffer from excessive chemical bonding and fiber rupture.
Demonstrates that ambient-cured One-Part PE-SHGC achieves an ultimate tensile strain capacity of 4.8 % (heat cured: 5.5 %), tensile strength of 5.1 MPa, and compressive strength of 42.5 MPa.

Evidence summary

Dry-Mix Matrix Formulation: Class F Fly Ash (60 wt%) + GGBFS (40 wt%) with dry solid powder activator (solid hydrous sodium silicate + solid $\text{Ca(OH)}2$), micro-silica sand ($d, S/B = 0.30$), $w/b = 0.33$.} = 150\ \mu\text{m
Fiber Properties ($V_f = 2.0\text{ vol. \%}$):
UHMWPE: $l_f = 12\text{ mm}, d_f = 24\ \mu\text{m}, \sigma_f = 3000\text{ MPa}, E_f = 100\text{ GPa}$.
PVA: $l_f = 8\text{ mm}, d_f = 40\ \mu\text{m}, \sigma_f = 1600\text{ MPa}, E_f = 41\text{ GPa}$.
Micromechanical & Single-Fiber Pullout Parameters:
PE in One-Part Matrix: $\tau_0 = 1.62\text{ MPa}$ (heat) / $2.24\text{ MPa}$ (ambient), $G_d \approx 0\text{ J/m}^2$ (pure friction), slip-hardening coefficient $\beta = 0.08\text{--}0.14$.
Matrix Toughness: $K_m = 0.48\text{ MPa}\cdot\text{m}^{1/2}$, $E_m = 14.5\text{ GPa}$, $J_{tip} = 15.9\text{ J/m}^2$.
PSH Index: $J_b'/J_{tip} = 4.8 \ge 3.0$; $\sigma_0/\sigma_{fc} = 1.65 \ge 1.20$.
Macroscopic Mechanical Properties:
Ambient-Cured One-Part PE-SHGC: $f_c = 42.5\text{ MPa}$, $\sigma_{fc} = 3.1\text{ MPa}$, $\sigma_u = 5.1\text{ MPa}$, $\epsilon_u = \mathbf{4.80\%}$.
Heat-Cured One-Part PE-SHGC: $f_c = 36.2\text{ MPa}$, $\sigma_{fc} = 2.7\text{ MPa}$, $\sigma_u = 4.5\text{ MPa}$, $\epsilon_u = \mathbf{5.50\%}$.
Ambient-Cured One-Part PVA-SHGC: $f_c = 48.0\text{ MPa}$, $\sigma_u = 3.6\text{ MPa}$, $\epsilon_u = 2.10\%$ (limited by PVA fiber rupture).

Linked Atlas nodes

02_concepts/strain_hardening_criteria.md
05_experiments/single_fiber_pullout.md
02_concepts/fiber_bridging_law.md
04_material_systems/geopolymer_ecc.md
04_material_systems/green_ecc.md
04_material_systems/pe_ecc.md
05_experiments/direct_tensile_test.md
05_experiments/single_fiber_pullout.md
02_concepts/circular_economy_materials.md

Relationship to Victor Li book

Extends Victor Li (2019) Chapter 4 (PSH Criteria), Chapter 7 (PE vs. PVA Micromechanics), and Chapter 9 (Green ECC).
Completes the micromechanical loop for one-part "dry-mix" geopolymers: applies single-fiber pullout testing to calibrate bridging laws and prove that hydrophobic PE fibers avoid the excessive chemical bonding that induces fiber rupture in high-calcium slag geopolymer matrices.

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`04_material_systems/pe_ecc.md`	Ambient-cured one-part "dry-mix" PE-EGC achieves 4.8 % direct tensile ductility and 42.5 MPa compressive strength	JSCE uniaxial direct tensile tests, single-fiber pullout, and cube compression	Section 3.1–3.3, Fig. 4-8, Table 3	verified_from_pdf
`05_experiments/single_fiber_pullout.md`	PE fibers in one-part geopolymer matrix exhibit slip-hardening frictional pullout ($\beta = 0.08\text{--}0.14, \tau_0 = 1.62\text{--}2.24\text{ MPa}$) with zero rupture	Single-fiber pullout testing and micromechanical constitutive modeling	Section 3.2, Fig. 5 & 6, Table 2	verified_from_pdf

Verification status

PDF preserved: yes (nematollahi-2017-one-part-shgc-pe-fiber-micromechanics.pdf)
Text extracted: yes (full_text/nematollahi-2017-one-part-shgc-pe-fiber-micromechanics_full_text.md)
DOI verified: yes (10.1016/j.acme.2016.12.005)
Metadata verified: yes (Arch. Civ. Mech. Eng., Vol. 17, No. 3, pp. 555–563, 2017)
Claim-evidence matrix ready: yes

Cautions

One-part solid activator powders must be stored in air-tight moisture-proof bags to prevent pre-hydration and cake formation before mixing.
PE fibers are hydrophobic; high-shear planetary mixing is necessary to ensure complete dispersion without air entrapment.