Artyk et al. (2024) — Development of Engineered Geopolymer Composites Containing Low-Activity Fly Ashes and Ground Granulated Blast Furnace Slags with Hybrid Fibers
Citation
Artyk, Z., Kuan, Y., Zhang, D., Shon, C.-S., Ogwumeh, C. M., & Kim, J. (2024). Development of engineered geopolymer composites containing low-activity fly ashes and ground granulated blast furnace slags with hybrid fibers. Construction and Building Materials, 422, 135760.
- DOI:
10.1016/j.conbuildmat.2024.135760 - Atlas layer: extension
- Related Victor Li book chapter: Chapter 8: Fiber Hybridization (PVA/PP/Steel Combinations) & Chapter 9: Green ECC (Alkali-Activated / Geopolymer Binders) & Chapter 11: Structural Applications (Masonry Retrofitting)
- Source PDF:
artyk-2024-development-of-engineered-geopolymer-composites-containing.pdf - Extracted text:
full_text/artyk-2024-development-of-engineered-geopolymer-composites-containing_full_text.md - Source note:
source_notes/artyk-2024-development-of-engineered-geopolymer-composites-containing_source_note.md
Why this paper matters
Demonstrates that low-grade, non-ASTM compliant coal fly ash (stockpiled in massive quantities in Central Asia) can be successfully blended 50/50 with GGBFS and alkali activators to produce ductile Engineered Geopolymer Composites (EGC). Integrates PVA, PP, and steel hybrid fibers to achieve $\epsilon_u > 2\%$ while providing thermal insulation ($k < 0.25\text{ W/m}\cdot\text{K}$) for masonry retrofitting.
Main contribution
- Overcomes the poor reactivity and coarse particle grading of low-activity fly ash (only 47 % passing 45 $\mu\text{m}$ sieve) by co-activating with GGBFS (50:50 mass ratio) using 12 M NaOH and $\text{Na}_2\text{SiO}_3$ ($\text{Na}_2\text{SiO}_3/\text{NaOH} = 2.5$).
- Evaluates hybrid fiber reinforcement (total 2.0 vol. %) using combinations of oiled PVA, PP, and hooked steel fibers to reduce material costs while maintaining pseudo strain-hardening.
- Attains multi-functional performance: compressive strength > 20 MPa, uniaxial tensile strain capacity > 2.0 %, and low thermal conductivity < 0.25 W/m·K tailored for structural-thermal retrofitting of unreinforced masonry.
- Establishes a micromechanical model using Gauss-Newton parameter estimation to predict composite bridging stress and strain capacity for various hybrid fiber formulations.
Evidence summary
- Binder & Activator Proportion: 50 % low-activity fly ash + 50 % GGBFS ($w/b = 0.38$, sand/binder = 0.36, activator/binder mass ratio = 0.35, 12 M NaOH, $\text{Na}_2\text{SiO}_3/\text{NaOH} = 2.5$).
- Direct Tensile Performance (Uniaxial Tension):
- Mono PVA (2.0 vol. %): $\epsilon_u = 2.45 \pm 0.3\%$, $\sigma_u = 3.8\text{ MPa}$.
- Hybrid PVA 1.5 % + PP 0.5 %: $\epsilon_u = 2.15 \pm 0.25\%$, $\sigma_u = 3.2\text{ MPa}$.
- Hybrid PVA 1.5 % + Steel 0.5 %: $\epsilon_u = 1.65 \pm 0.2\%$, $\sigma_u = 4.1\text{ MPa}$.
- Mono PP (2.0 vol. %): localized failure with minimal strain-hardening ($\epsilon_u < 0.8\%$).
- Compressive Strength: 22–32 MPa across geopolymer mixes at 28 days under ambient/standard curing.
- Thermal Conductivity: 0.21–0.24 W/m·K, significantly lower than conventional concrete (~1.0–1.5 W/m·K).
Linked Atlas nodes
02_concepts/strain_hardening_criteria.md04_material_systems/engineered_geopolymer_composites.md04_material_systems/hybrid_fiber_ecc.md05_experiments/direct_tensile_test.md04_material_systems/industrial_waste_streams.md
Relationship to Victor Li book
- Extends Victor Li (2019) Chapter 8 (Fiber Hybridization) by examining cost-effective PVA/PP/Steel hybrid combinations in zero-cement geopolymer matrices.
- Extends Chapter 9 (Green ECC) by demonstrating that even low-activity/off-spec fly ashes can meet PSH criteria when combined with GGBFS and alkali activation.
- Supports Chapter 11 (Applications) by aligning composite ductility ($\epsilon_u > 2\%$) and low modulus with the deformational and thermal requirements of unreinforced masonry retrofitting.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
04_material_systems/engineered_geopolymer_composites.md |
Low-activity fly ash blended with GGBFS (50:50) forms an alkali-activated matrix capable of pseudo strain-hardening | 28d compressive strength reached 23–32 MPa and tensile strain capacity exceeded 2.0 % with PVA/PP fibers | Section 3.1 & 3.3, Fig. 5-7, Table 6 | verified_from_pdf |
04_material_systems/hybrid_fiber_ecc.md |
Hybridizing 1.5 vol. % PVA with 0.5 vol. % PP maintains tensile strain capacity > 2.0 % while reducing composite cost | Uniaxial tensile strain capacity reached $2.15\%$ with multi-cracking behavior | Section 3.3, Fig. 7, Table 6 | verified_from_pdf |
04_material_systems/industrial_waste_streams.md |
Zero-cement EGC exhibits low thermal conductivity (< 0.25 W/m·K), facilitating energy-efficient retrofitting | Measured thermal conductivity was 0.21–0.24 W/m·K across all EGC formulations | Section 3.4, Fig. 8 | verified_from_pdf |
Verification status
- PDF preserved: yes (
artyk-2024-development-of-engineered-geopolymer-composites-containing.pdf) - Text extracted: yes (
full_text/artyk-2024-development-of-engineered-geopolymer-composites-containing_full_text.md) - DOI verified: yes (
10.1016/j.conbuildmat.2024.135760) - Metadata verified: yes (CBM, Vol. 422, 135760, 2024)
- Claim-evidence matrix ready: yes
Cautions
- Low-activity fly ash requires co-blending with GGBFS to supply necessary $Ca^{2+}$ ions and ensure room-temperature hardening.
- Mono PP fiber without PVA fails to achieve adequate strain-hardening ($\epsilon_u < 1\%$) due to low elastic modulus and weak interfacial friction in geopolymer pastes.