Recycled Selvage Fiber ECC Position

1. Research axis definition

This axis positions Professor Bang Yeon Lee's lab as a contributor to circular-economy ECC, where high-performance textile waste, especially PE-based selvage fibers, is converted into structural reinforcement for strain-hardening cementitious composites.

The axis addresses a central bottleneck in ECC deployment:

high ductility requires high-performance synthetic fibers
  -> virgin PE/PVA fibers are costly and embodied-energy intensive
    -> textile selvage waste provides high-strength PE filaments
      -> mechanical processing + dispersion control
        -> ductile, lower-cost, greener ECC/EGC

2. Global literature anchor

Global anchor nodes:

• [[green_ecc]]: sustainability must preserve ECC tensile ductility and crack-width control.
• [[fiber_dispersion]]: recycled fibers must disperse without clumping.
• [[strain_hardening_criteria]]: recycled fibers remain useful only if bridging capacity exceeds cracking strength.
• [[crack_width_distribution]]: durability requires crack widths remain controlled.

This axis extends the global Green ECC literature by showing that recycled fibers need not always reduce tensile performance if the waste stream retains high-performance PE filaments and is processed appropriately.

3. Lee lab representative papers

4. Key evidence and metrics

• Choi et al. 2022: 16 mm cut PE selvage fibers reached 10.81 MPa tensile strength and 6.55% tensile strain capacity, exceeding virgin PE control ductility in the source-note evidence.
• Choi et al. 2022: replacing virgin PE fibers with upcycled selvage fibers reduced material cost by 75.7% in the recorded MSI analysis.
• Nguyen et al. 2024: recycled selvage fiber ECC linked recycled reinforcement to crack healing and high-performance ECC behavior.
• Hwang et al. 2025: single-fiber pullout evidence supports PE filament frictional pullout as the key load-transfer mechanism.
• Park et al. 2025: PE selvage fiber length affects fresh behavior, dispersion, tensile strength, ductility, and crack width.

5. What is distinctive about Lee lab contribution

The distinctive point is not merely using recycled fibers. The lab identifies a specific recycled fiber stream with high-value PE filaments and then connects processing, dispersion, interface behavior, tensile strain-hardening, cost reduction, and crack-width behavior into one material design pathway.

6. Strategic novelty claims

• Lee lab reframes textile selvage waste as a high-performance reinforcement source rather than low-grade filler.
• The selvage-fiber line provides a rare recycled-fiber ECC route that can retain multi-percent ductility rather than only reducing cost.
• The lab connects circular economy, fiber processing, and PSH performance in a source-grounded way.
• Selvage-fiber ECC can be positioned as a practical bridge between laboratory ECC and cost-sensitive infrastructure deployment.

7. Manuscript intro/discussion reusable paragraphs

Intro paragraph draft:

The high cost and embodied energy of synthetic fibers remain major barriers to broader ECC deployment. Many recycled fiber approaches reduce environmental burden but also reduce tensile performance. The Lee lab's selvage-fiber research line addresses this trade-off by using high-performance PE filament waste from textile manufacturing, showing that circular-economy fibers can still support strain-hardening when length, dispersion, and interface behavior are controlled.

Discussion paragraph draft:

The current results should be viewed as part of a recycled high-performance fiber lineage. Unlike generic recycled polymer fibers, PE-based selvage fibers preserve high tensile strength and frictional pullout potential. This allows recycled-fiber ECC to move beyond cost reduction toward genuine performance retention.

8. Proposal background reusable paragraphs

A circular construction-materials strategy requires more than replacing virgin raw materials with waste. The replacement must preserve structural function. Recycled PE selvage fibers provide a promising high-value waste stream because their filament strength and pullout behavior can contribute to ECC bridging. This creates a research pathway where textile waste valorization, crack-width-controlled durability, and cost-effective ductile composites are pursued simultaneously.

9. Open research opportunities

1. Scaling mechanical unraveling and cutting processes for selvage fibers.
2. Standardizing fiber length distribution and dispersion metrics.
3. Long-term durability and creep/shrinkage behavior of selvage-fiber ECC.
4. Coupling selvage fibers with cementless binders and low-fiber strategies.
5. Developing cost-performance-CO2 optimization models for recycled-fiber ECC.

10. Linked Atlas nodes and source files

• [[green_ecc]] — 04_material_systems/green_ecc.md
• [[fiber_dispersion]] — 02_concepts/fiber_dispersion.md
• [[strain_hardening_criteria]] — 02_concepts/strain_hardening_criteria.md
• [[crack_width_distribution]] — 05_experiments/crack_width_distribution.md
• [[single_fiber_pullout]] — 05_experiments/single_fiber_pullout.md
• Lab mapping: 06_lab_position/by_lee_publication_mapping.csv
• Lab claim matrix: 07_visualization/by_lee_lab_publications_claim_evidence_matrix.csv