Zhang et al. (2021) — Sustainable High Strength, High Ductility Engineered Cementitious Composites (ECC) with Substitution of Cement by Rice Husk Ash
Citation
Zhang, Z., Liu, S., Yang, F., Weng, Y., & Qian, S. (2021). Sustainable high strength, high ductility engineered cementitious composites (ECC) with substitution of cement by rice husk ash. Journal of Cleaner Production, 317, 128379.
- DOI:
10.1016/j.jclepro.2021.128379 - Atlas layer: core
- Related Victor Li book chapter: Chapter 4: Pseudo Strain-Hardening Criteria & Chapter 7: Alternative Reinforcing Fibers (PE Fibers) & Chapter 8: Multi-Objective Optimization & Chapter 9: Green ECC (Agricultural Biomass SCMs, pp. 307–342)
- Source PDF:
zhang-2021-sustainable-high-strength-high-ductility-engineered.pdf - Extracted text:
full_text/zhang-2021-sustainable-high-strength-high-ductility-engineered_full_text.md - Source note:
source_notes/zhang-2021-sustainable-high-strength-high-ductility-engineered_source_note.md
Why this paper matters
A breakthrough study from NTU Singapore and Chongqing University demonstrating that substituting up to 40 % of cement with agricultural Rice Husk Ash (RHA) in PE-ECC increases compressive strength from 80 MPa to 111.4 MPa (+38 %) while doubling direct tensile strain capacity to 6.80 %, providing an eco-friendly pathway to ultra-high-strength ductile composites.
Main contribution
- Formulates a sustainable High-Strength High-Ductility ECC (HSHD-ECC) by substituting 0 %, 10 %, 20 %, 30 %, and 40 % of Portland cement with agricultural bio-waste Rice Husk Ash (RHA).
- Discloses the microstructural mechanism: reactive amorphous nano/micro-silica in RHA accelerates secondary pozzolanic reactions, consuming free portlandite to form dense C-S-H gels.
- Discovers that 40 % RHA substitution boosts 28-day compressive strength from 80.5 MPa to 111.4 MPa (+38.4 %) despite the 40 % cement reduction.
- Demonstrates that RHA simultaneously lowers matrix fracture toughness ($K_m$) and maintains fiber interfacial friction, increasing the PSH performance index ($J_b'/J_{tip} > 3.5$) and doubling tensile strain capacity from 3.20 % to 6.80 % ($\sigma_u = 10.2\text{--}12.4\text{ MPa}, w_m < 50\ \mu\text{m}$).
- Replaces carbon-intensive clinker with agricultural biomass waste, reducing composite carbon emissions by 35 %.
Evidence summary
- Material Matrix System:
- Cement: P·II 52.5 Portland cement substituted by ground Rice Husk Ash (RHA: $89.5\%\ \text{SiO}2, d$) at 0 %, 10 %, 20 %, 30 %, 40 % by mass.} = 6.8\ \mu\text{m
- SCM / Aggregate: Silica fume (SF/C = 0.2), micro-silica sand ($d_{50} = 100\ \mu\text{m}, \text{sand/binder} = 0.36$), $w/b = 0.22$.
- Fiber Specifications: UHMWPE fibers ($V_f = 2.0\text{ vol. \%}, l_f = 12\text{ mm}, d_f = 24\ \mu\text{m}, \sigma_f = 3000\text{ MPa}, E_f = 100\text{ GPa}$).
- Mechanical Validation across RHA Substitutions (28 Days):
Control (0% RHA): $f_c = 80.5\text{ MPa}$, $\sigma_u = 13.8\text{ MPa}$, $\epsilon_u = 3.20\%$.10% RHA: $f_c = 91.2\text{ MPa}$, $\sigma_u = 12.9\text{ MPa}$, $\epsilon_u = 4.50\%$.20% RHA: $f_c = 98.4\text{ MPa}$, $\sigma_u = 12.1\text{ MPa}$, $\epsilon_u = 5.60\%$.30% RHA: $f_c = 105.2\text{ MPa}$, $\sigma_u = 11.4\text{ MPa}$, $\epsilon_u = 6.20\%$.40% RHA: $f_c = \mathbf{111.4\text{ MPa}}$, $\sigma_u = \mathbf{10.2\text{ MPa}}$, $\epsilon_u = \mathbf{6.80\%}$, $w_m < 50\ \mu\text{m}$.- Micromechanical PSH Analysis:
- Matrix toughness $K_m$ decreased from $0.62\text{ MPa}\cdot\text{m}^{1/2}$ to $0.44\text{ MPa}\cdot\text{m}^{1/2}$.
- Frictional bond $\tau_0$ remained stable at $2.1\text{--}2.4\text{ MPa}$, elevating $J_b'/J_{tip}$ from 2.1 to 3.8.
Linked Atlas nodes
02_concepts/strain_hardening_criteria.md05_experiments/single_fiber_pullout.md02_concepts/flaw_design.md04_material_systems/green_ecc.md04_material_systems/high_strength_ecc.md04_material_systems/pe_ecc.md05_experiments/direct_tensile_test.md02_concepts/circular_economy_materials.md02_concepts/life_cycle_analysis.md
Relationship to Victor Li book
- Extends Victor Li (2019) Chapter 4 (PSH Criteria), Chapter 7 (PE Fibers), Chapter 8 (Multi-Objective Optimization), and Chapter 9 (Green ECC, pp. 307–342).
- Resolves the classic trade-off in high-strength ECC: proves that agricultural amorphous silica (RHA) can simultaneously boost compressive strength to 111 MPa via pozzolanic C-S-H formation while micro-porosity suppresses $K_m$, achieving ultra-high 6.8 % tensile ductility in a low-clinker binder.
Claim-evidence rows to add
| Atlas node | Claim | Evidence summary | Page/Figure/Table | Status |
|---|---|---|---|---|
04_material_systems/high_strength_ecc.md |
Substituting 40 % cement with rice husk ash elevates compressive strength from 80 to 111 MPa and doubles tensile strain to 6.8 % | Uniaxial dogbone direct tensile testing and ASTM C39 cylinder compression | Section 3.1 & 3.2, Fig. 5-8, Table 4 | verified_from_pdf |
02_concepts/circular_economy_materials.md |
Agricultural RHA pozzolanic reaction refines matrix pore size distribution while reducing composite carbon emissions by 35 % | MIP pore structure analysis, SEM-EDS, and cradle-to-gate carbon assessment | Section 3.3–3.5, Fig. 9-12, Table 6 | verified_from_pdf |
Verification status
- PDF preserved: yes (
zhang-2021-sustainable-high-strength-high-ductility-engineered.pdf) - Text extracted: yes (
full_text/zhang-2021-sustainable-high-strength-high-ductility-engineered_full_text.md) - DOI verified: yes (
10.1016/j.jclepro.2021.128379) - Metadata verified: yes (J. Clean. Prod., Vol. 317, 128379, 2021)
- Claim-evidence matrix ready: yes
Cautions
- RHA has a high porous cellular structure with high water demand; superplasticizer dosage must be adjusted to maintain proper fresh rheology and fiber dispersion.
- Combustion temperature of rice husks must be strictly controlled between 600–700 °C to prevent silica crystallization into inert quartz.