Coconut coir is already established in erosion control, horticulture and fibre products. A 2026 study in the Journal of Materials in Civil Engineering tested a more demanding pathway: using discarded coir as reinforcement in pavement-quality concrete and comparing it directly with micropolypropylene synthetic fibre.
1. What the researchers tested
The team investigated plastic-shrinkage cracking, bleeding and mechanical behaviour in paving concrete containing coir, synthetic fibre and steel-fibre systems. The comparison matters because early-age plastic-shrinkage cracks can reduce pavement durability and increase maintenance needs.
2. Coir arrested plastic-shrinkage cracking at a lower dosage
In the reported tests, coir completely arrested plastic-shrinkage cracking at a dosage of 0.3% by concrete volume, while 0.4% synthetic fibre was required. The researchers linked this partly to coir having a 27% rougher surface texture than the synthetic fibre used in the study.
3. Bleeding fell, but compressive strength showed a trade-off
Coir reduced cumulative bleeding by 45% compared with conventional paving concrete. However, coir-reinforced paving concrete showed about 10% lower compressive strength than the synthetic-fibre system. That is an important reminder that a natural-fibre substitution should be evaluated across several performance criteria, not on one headline number.
4. Toughness was a notable strength
Despite the lower compressive-strength result, the coir system delivered more than 10% higher toughness than the synthetic-fibre system. When coir was incorporated into steel-fibre paving concrete, the study reported a 135% increase in toughness and a 17% increase in abrasion resistance compared with conventional paving concrete.
CTN interpretation: this research does not mean every road-concrete mix should replace polypropylene with coir. It shows that properly prepared coir can perform a serious engineering role under the tested mix designs, while specification, fibre treatment, dosage, durability and local standards still need project-level validation.
5. Why this matters for coconut-producing countries
Coir is a renewable lignocellulosic fibre generated from coconut husk. If engineering applications can absorb suitable grades of discarded fibre, they could diversify demand beyond traditional coir markets and create additional pathways for husk valorisation. For Indonesia, the opportunity is particularly relevant where coconut processing and infrastructure development coexist.
6. What construction buyers should ask
Commercial evaluation should define fibre length and grading, moisture and cleanliness, pre-treatment, dosage, dispersion, concrete mix design, strength targets, abrasion requirements, long-term durability and compliance with local pavement standards. Laboratory results should not be treated as a universal construction specification.
7. The bigger signal
The study strengthens a broader trend in natural-fibre engineering: agricultural residues are increasingly being tested against established synthetic materials using measurable performance criteria. For coir suppliers, that shifts the conversation from “green material” to repeatable fibre quality and application-specific engineering.
Sources & further reading
This is original CTN editorial analysis. Research findings are presented in context and should not be treated as universal product-performance guarantees.
- Primary research: https://doi.org/10.1061/JMCEE7.MTENG-22242.
Have a related sourcing requirement?
Share the application, material specification, quantity, destination and required documentation. WAZ can help structure the requirement and connect relevant Indonesian capabilities for commercial discussion.
Submit Requirement