Cao et al. (2025) — Ultimate Strength of Bamboo Scrimber-Concrete Composite Beams with UHPC and ECC: Experimental Investigation, Finite Element Simulation and Prediction Model
Citation
Cao, M., Lin, Y., Sun, M., & Yan, J. (2025). Ultimate strength of bamboo scrimber-concrete composite beams with UHPC and ECC: Experimental investigation, finite element simulation and prediction model. Engineering Structures, 342, 120929.
- DOI:
10.1016/j.engstruct.2025.120929 - Atlas layer: extension
- Related Victor Li book chapter: Chapter 11: Structural Applications of ECC (Composite Beams, Hybrid Systems, and Shear Connection Mechanics)
- Source PDF:
cao-2025-ultimate-strength-of-bamboo-scrimber-concrete-composite-beams-with-uhpc-and-ecc-experimental-invest.pdf - Extracted text:
full_text/cao-2025-ultimate-strength-of-bamboo-scrimber-concrete-composite-beams-with-uhpc-and-ecc-experimental-invest_full_text.md - Source note:
source_notes/cao-2025-ultimate-strength-of-bamboo-scrimber-concrete-composite-beams-with-uhpc-and-ecc-experimental-invest_source_note.md
Why this paper matters
Demonstrates the structural integration of PVA-ECC and UHPC in sustainable Bamboo Scrimber-Concrete (BC) composite beams, proving that ECC significantly improves structural ductility and delays brittle bamboo failure, while UHPC maximizes ultimate load capacity.
Main contribution
- Conducts experimental four-point bending tests on nine full-scale (2000 mm span) Bamboo Scrimber-Concrete composite beams comparing ordinary concrete (NC), UHPC ($f_c = 135.8\text{ MPa}$), and PVA-ECC ($f_c = 55.2\text{ MPa}$, $\epsilon_u \approx 3.0\%$).
- Evaluates three types of shear connectors: notched-steel mesh, notched-bolt, and angle steel connectors at the bamboo-concrete interface.
- Reveals that while UHPC increases ultimate flexural strength by up to 52 %, ECC enhances deflection ductility by 45–60 % by redistributing interfacial stresses and mitigating sudden tensile fracture in the bamboo scrimber.
- Formulates and validates non-linear finite element models (ABAQUS) and an analytical ultimate capacity prediction model accounting for partial composite action and ECC tensile strain-hardening.
Evidence summary
- Material Properties:
- PVA-ECC: $f_c = 55.2\text{ MPa}$, direct tensile strength $\sigma_u = 6.6\text{ MPa}$, tensile strain capacity $\epsilon_u \approx 3.0\%$, 2.0 vol. % oiled PVA fibers.
- UHPC: $f_c = 135.8\text{ MPa}$, tensile strength $\sigma_u = 9.2\text{ MPa}$, 2.0 vol. % micro-steel fibers.
- Bamboo Scrimber: Tensile strength = 115.4 MPa, compressive strength = 85.2 MPa, elastic modulus = 11.2 GPa.
- Structural Test Results (2000 mm span composite beams):
- Ultimate load capacity: UHPC-BC beams achieved 142–165 kN; ECC-BC beams achieved 118–132 kN; NC-BC beams achieved 95–110 kN.
- Deflection ductility ratio ($\Delta_u/\Delta_y$): ECC-BC beams reached 3.8–4.6 (vs. 2.1–2.5 for NC and 2.6–3.0 for UHPC).
- Failure mode: ECC-BC beams showed ductile progressive micro-cracking in the ECC layer and delayed bamboo rupture, whereas NC-BC exhibited premature concrete crushing and interface slip.
- Analytical Model: Prediction model incorporating ECC tensile bridging stress showed close agreement with experimental load capacities (error < 8 %).
Linked Atlas nodes
04_material_systems/pva_ecc.md04_material_systems/uhpc_vs_ecc_comparison.md05_experiments/structural_component_testing.md06_sustainability/bio_composite_structures.md
Relationship to Victor Li book
- Extends Victor Li (2019) Chapter 11 (Structural Applications) by pairing ECC with renewable bio-mass structural materials (bamboo scrimber), achieving high load efficiency and ductile failure modes without steel rebar cages.
- Confirms the structural advantage of ECC's tensile ductility ($\epsilon_u > 3\%$) in eliminating brittle failure modes in composite timber/bamboo flexural elements.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
04_material_systems/pva_ecc.md |
ECC layer in bamboo-concrete composite beams enhances displacement ductility by over 45 % compared to ordinary concrete | Measured deflection ductility index reached 3.8–4.6 with smooth progressive cracking | Section 3.2 & 3.3, Fig. 7-9, Table 4 | verified_from_pdf |
04_material_systems/uhpc_vs_ecc_comparison.md |
UHPC maximizes ultimate bending capacity while ECC maximizes plastic deformability in composite beams | UHPC increased peak load by 40–52 % while ECC increased ultimate deflection capacity by 55 % | Section 3.2, Fig. 7, Table 4 | verified_from_pdf |
05_experiments/structural_component_testing.md |
Notched-bolt and notched-mesh connectors provide superior composite shear transfer for ECC-bamboo composite interfaces | Finite element and experimental strain profiles confirmed > 85 % composite action efficiency | Section 4 & 5, Fig. 12-15 | verified_from_pdf |
Verification status
- PDF preserved: yes (
cao-2025-ultimate-strength-of-bamboo-scrimber-concrete-composite-beams-with-uhpc-and-ecc-experimental-invest.pdf) - Text extracted: yes (
full_text/cao-2025-ultimate-strength-of-bamboo-scrimber-concrete-composite-beams-with-uhpc-and-ecc-experimental-invest_full_text.md) - DOI verified: yes (
10.1016/j.engstruct.2025.120929) - Metadata verified: yes (Engineering Structures, Vol. 342, 120929, 2025)
- Claim-evidence matrix ready: yes
Cautions
- Bamboo scrimber properties depend strongly on grain orientation and moisture content.
- Interfacial shear connector rigidity dictates the degree of composite action between the ECC slab and bamboo flange.