Chitosan fibers in concrete - an innovative approach to sustainable construction materials

The construction industry is facing a major challenge: developing materials that are more durable, high-performing, and at the same time significantly more sustainable. Alongside advances in cement formulations, bio-based functional materials are increasingly gaining attention in research and development. One particularly promising candidate is chitosan - a natural biopolymer with unique chemical and structural properties.

A recent scientific study highlights the potential of self-shrinking chitosan fibers for next-generation concrete materials, while also outlining the areas where further research can unlock even greater performance.

Why chitosan is such a remarkable material

Chitosan is derived from chitin, one of the most abundant natural polymers worldwide. Its most distinctive feature is its pH-responsive behavior:
In highly alkaline environments, such as the pore solution of concrete, chitosan undergoes chemical changes that cause the material to shrink.
This property makes chitosan particularly attractive for construction materials research. When used as fibers in concrete, chitosan can generate internal compressive stresses during curing, which may:

• reduce microcrack formation
• densify the internal structure
• improve long-term durability

This opens up an entirely new pathway for self-active and functional fiber systems in cement-based materials.

Two chitosan types - one shared mechanism

The study investigated two different chitosan qualities: Both types were successfully processed into fibers and incorporated into a sustainable high-performance concrete based on Portland limestone cement and ground glass pozzolan.
The key finding: Both chitosan types exhibit pronounced self-shrinking behavior under alkaline concrete conditions.
With a length reduction of approximately 37%, the fibers clearly demonstrate that the fundamental mechanism works - an important milestone in the development of self-shrinking fiber technologies.

Positive effects on durability

One of the most compelling results concerns freeze–thaw resistance:

• Concrete containing food-grade chitosan fibers showed very high resistance to freeze-thaw cycling at moderate dosages
• Even after more than 600 freeze-thaw cycles, the material remained structurally stable
• These results suggest that chitosan fibers can beneficially influence moisture transport and pore structure within the concrete matrix

For applications where long service life is critical, this represents a highly promising avenue.

Mechanical performance - an approach with strong development potential

As with any innovative material, optimization is essential.
The study shows that compressive strength is currently influenced by fiber type, dosage, and interactions with the cement matrix.
Rather than a limitation, these findings provide valuable guidance for further development:

• optimization of fiber surface properties to improve bonding
• targeted adjustment of molecular weight and degree of deacetylation
• combination with other functional additives
• adaptation to non-structural or hybrid load-bearing applications

This is precisely where chitosan offers exceptional flexibility as a tunable biopolymer.

Which chitosan types are especially promising?

The results clearly demonstrate that chitosan is not a uniform material, but a highly adaptable one.
For future concrete applications, particularly promising directions include:

• modified chitosan with functionalized surfaces
• chitosan with tailored molecular weight distributions
• hybrid systems combining chitosan with mineral or polymer-based components

Potential applications include specialty concretes, repair and rehabilitation mortars, durable coatings, and sustainable functional materials.

Conclusion: chitosan as a building block for next-generation materials
The study clearly demonstrates that chitosan fibers hold significant innovation potential for sustainable concrete technologies. Their self-shrinking behavior, positive influence on durability, and bio-based origin make chitosan a highly attractive material for future-oriented construction solutions.
As with any true innovation:
The greatest opportunities lie in continued development.
With optimized chemistry, tailored fiber design, and clearly defined application fields, chitosan can become an important component of the next generation of functional, resource-efficient construction materials.

Source
Abdul Qader, M.A.; Hughes, S.; Huston, D.; Dewoolkar, M.M. Shrinking Chitosan Fibers in Concrete: A Macroscale Durability and Strength Assessment. Fibers 2026, 14, 18. https://doi.org/10.3390/fib14020018

First published on 12th of February 2026

Revised on 12th of February 2026