ECC / SHCC / EGC Introduction

1. Learning objectives

• Explain the brittleness problem in ordinary concrete.
• Distinguish ECC/SHCC/EGC from FRC and UHP-FRC.
• Understand the Atlas evidence hierarchy.

2. Key concepts

• Tensile strain-hardening
• Multiple microcracking
• Crack-width control
• ECC vs FRC vs UHP-FRC
• Book / paper / extension / lab evidence layers

3. Minimal theory

ECC is identified by tensile strain-hardening and distributed microcracking. The teaching focus is not only compressive strength but tensile deformation capacity and damage control.

4. Source-grounded evidence

• Primary anchor: 00_sources/victor_li_book/.
• System overview: index.md.
• Foundational support: 07_visualization/foundational_papers_claim_evidence_matrix.csv.

5. Representative papers

• Victor C. Li 2019 ECC book.
• Li, Wang & Wu 2001 PVA-ECC tensile strain-hardening.
• Kanda & Li 2006 practical PSH criteria.

6. Figures/tables to show later

• Stress-strain comparison of concrete, FRC, ECC.
• Multiple cracking photograph.
• Atlas evidence hierarchy diagram.

7. Discussion questions

1. Why is tensile ductility central to ECC identity?
2. Can a green brittle composite be called Green ECC?
3. Why does EGC belong in the ECC/SHCC family?

8. Assignment idea

Classify five example materials as concrete, FRC, UHP-FRC, ECC, or EGC using tensile response and crack pattern.

9. Linked Atlas nodes

• index.md
• 02_concepts/strain_hardening_criteria.md
• 02_concepts/distributed_microcracking.md
• 05_experiments/direct_tensile_test.md

10. Suggested reading path

1. index.md
2. 02_concepts/strain_hardening_criteria.md
3. 05_experiments/direct_tensile_test.md

Evidence files

• 07_visualization/foundational_papers_claim_evidence_matrix.csv
• 07_visualization/extreme_ductility_extension_claim_evidence_matrix.csv
• 07_visualization/sustainable_ecc_extension_claim_evidence_matrix.csv
• 07_visualization/by_lee_lab_publications_claim_evidence_matrix.csv