As the construction sector seeks lower-carbon alternatives to traditional materials, biomass-based composites are attracting growing attention. However, integrating plant fibers into cement systems has remained challenging, largely due to poor interfacial compatibility and structural instability.
A recent study offers a practical solution by focusing on bamboo processing waste, an abundant but underutilized resource. According to the study, roughly 35%–50% of bamboo is discarded during processing, often ending up as landfill or incineration waste. Converting this material into functional composites could improve both resource efficiency and environmental performance.
The research centers on magnesium oxychloride cement (MOC), a low-carbon alternative to Portland cement. MOC requires significantly lower calcination temperatures and produces substantially less carbon dioxide, making it a promising candidate for green construction materials. However, its brittleness and sensitivity to moisture have limited broader application.
To address these issues, the study introduces a mild ammonium carbonate treatment to modify bamboo scraps before incorporation into the cement matrix. Unlike conventional strong alkali treatments, which can damage fiber structure and generate high environmental loads, this approach selectively removes non-cellulosic components such as lignin and hemicellulose while preserving the integrity of cellulose fibers.
This treatment produces two key effects. First, it softens the rigid bamboo structure, reducing its tendency to disrupt pore formation during composite processing. Second, it exposes hydrophilic functional groups on the fiber surface, which improves bonding with the inorganic matrix. As a result, needle-like crystalline phases characteristic of MOC are able to grow into surface micropores, forming a stronger interfacial "anchoring" structure.
Microstructural observations show that untreated bamboo tends to damage pore integrity, leading to irregular structures and stress concentration. In contrast, treated bamboo promotes more uniform pore distribution and stabilizes the foam structure within the composite. This improved pore architecture not only enhances mechanical strength but also reduces thermal conductivity by limiting heat transfer pathways.
Performance testing confirms these structural advantages. Under optimized treatment conditions, the composites exhibited a 45% increase in compressive strength, a 12% improvement in softening coefficient, and a 15% reduction in thermal conductivity. These gains indicate a balance between mechanical robustness and insulation performance, which is often difficult to achieve in lightweight materials.
The study also highlights environmental benefits associated with the process. Compared with traditional sodium hydroxide treatment, the ammonium carbonate method produces significantly lower chemical oxygen demand in wastewater, while residual ammonia can be recovered and reused as fertilizer, reducing overall environmental burden.
Taken together, the findings suggest that moderate chemical modification of biomass can effectively bridge the compatibility gap between organic fibers and inorganic binders. The approach provides a feasible route for producing lightweight, high-performance building materials from agricultural waste.
The authors note that such materials could find applications in insulation panels, building fillers, and fire-resistant components, contributing to more sustainable construction systems.
See the article:
DOI
https://doi.org/10.1016/j.jobab.2026.100252
Original Source URL
https://www.sciencedirect.com/science/article/pii/S2369969826000241
Journal
Journal of Bioresources and Bioproducts
