Choi & Lee (2015) — Bonding Properties of Basalt Fiber & Strength Reduction

Citation

Jeong-Il Choi, Bang Yeon Lee (2015). Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation. Materials, 8(10), 6719–6727.

DOI: 10.3390/ma8105335
Atlas layer: supporting
Related Victor Li book chapter: Chapter 3: Fiber/Matrix Interface and Single Fiber Pullout (also Chapter 4)
Source PDF: primary_data/choi-2015-bonding-properties-of-basalt-fiber.pdfIJP02015E_Bonding properties of basalt_materials.pdf`
Extracted text: secondary_data/full_texts/choi-2015-bonding-properties-of-basalt-fiber_full_text.mdsecondary_data/full_texts/IJP02015E_Bonding properties of basalt_materials_full_text.md`
Source note: secondary_data/source_notes/choi-2015-bonding-properties-of-basalt-fiber_source_note.mdsecondary_data/source_notes/IJP02015E_Bonding properties of basalt_materials_source_note.md`

Why this paper matters

Provides a vital micromechanical evaluation of basalt mineral fibers in cementitious matrices, proving why raw basalt fibers cause post-cracking strain-softening due to excessive chemical bonding ($G_d = 2.59\text{ J/m}^2$) and high inclination strength reduction ($f' = 1.535$).

Main contribution

Chemical Bond Evaluation: Quantified that untreated basalt fibers develop an 87.6 % higher chemical bond ($G_d = 2.59\text{ J/m}^2$) with alkali-activated slag matrix compared to PVA fibers ($1.38\text{ J/m}^2$).
Inclined Strength Degradation: Discovered that basalt fibers suffer an 83 % drop in apparent tensile strength at 67.5° inclination ($f' = 1.535$), which is 9 times more severe than PVA ($f'=0.171$) and 3 times more severe than PE ($f'=0.475$).
Interface Tailoring Requirement: Proved theoretically that raw basalt fiber composites cannot achieve pseudo strain-hardening (PSH) without surface coatings to reduce $G_d$ and prevent fiber rupture.

Evidence summary

Interfacial Properties: $G_d = 2.59\text{ J/m}^2$, $\tau_0 = 1.08\text{ MPa}$, $\beta = 0.0054$ for basalt in 42 MPa slag matrix (Table 5, Page 6724).
Inclination Strength: Basalt tensile strength dropped from $1773\text{ MPa}$ (0°) to $302\text{ MPa}$ (67.5°), giving $f' = 1.535$ (Table 6, Page 6725).
Bridging Curve: Theoretical $\sigma_B(\delta)$ shows post-cracking softening due to widespread fiber rupture (Fig. 5, Page 6726).

Linked Atlas nodes

02_concepts/interface_properties.md
02_concepts/fiber_bridging_law.md
02_concepts/strain_hardening_criteria.md

Relationship to Victor Li book

Primary book anchor remains Victor Li (2019), Engineered Cementitious Composites (ECC).
Directly supports Chapter 3 (Interface & Single Fiber Pullout) by confirming the necessity of interface chemical tailoring to avoid the premature rupture seen in raw mineral fibers.

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`02_concepts/interface_properties.md`	Basalt fiber forms excessive chemical bonding ($G_d = 2.59\text{ J/m}^2$, 87.6 % higher than PVA) with cementitious matrix	Single-fiber pullout in 42 MPa matrix yielded $G_d = 2.59\text{ J/m}^2$ for basalt vs $1.38\text{ J/m}^2$ for PVA	Page 6724 / Table 5	verified_from_pdf
`02_concepts/interface_properties.md`	Basalt fiber experiences severe inclination strength reduction ($f' = 1.535$, 9x higher than PVA), losing 83 % strength at 67.5°	Apparent strength decreased from 1773 MPa at 0° to 302 MPa at 67.5° ($f'=1.535$)	Page 6724 & 6725 / Table 6	verified_from_pdf
`02_concepts/fiber_bridging_law.md`	Raw basalt fiber reinforcement induces post-cracking strain-softening due to fiber rupture	Analytical bridging curves show rapid stress drop after first cracking in basalt-reinforced matrix	Page 6725 & 6726 / Fig. 5	verified_from_pdf

Verification status

PDF preserved: yes (in primary_data/IJP02015E_Bonding properties of basalt_materials.pdf)
Text extracted: yes (PyMuPDF, 9 pages)
DOI verified: yes (10.3390/ma8105335)
Page/figure/table verified: yes (all checked in PDF text)
Claim-evidence matrix ready: yes

Cautions

This is a boundary/negative benchmark: untreated basalt fiber causes strain-softening and does NOT exhibit ECC tensile ductility.