In the quest for sustainable construction materials, researchers have turned to an unlikely source: bamboo. A recent study published in *Scientific Reports* (translated from its original name, *Nature Scientific Reports*) reveals that bamboo stem ash (BSA) can significantly enhance the properties of lightweight foam mortar (LFM), offering a promising alternative to traditional cement. This innovation could reshape the energy sector by providing more eco-friendly and efficient building solutions.
The research, led by Md Azree Othuman Mydin from the School of Housing, Building, and Planning at Universiti Sains Malaysia, explores the potential of BSA as a partial cement replacement in LFM. Unlike conventional supplemental cementitious materials (SCMs) such as fly ash or silica fume, BSA offers a unique combination of lightweight properties and high silica concentration. This dual advantage makes it an attractive option for improving the mechanical, thermal, and microstructural characteristics of LFM.
The study found that incorporating BSA at 15% replacement level yielded the best results, with a compressive strength of 8.25 MPa at 28 days—7% higher than the control mix. “This optimal replacement level strikes a balance between mechanical strength, durability, and thermal insulation,” Mydin explained. Beyond 15%, increased porosity begins to reduce strength, although thermal resistance continues to improve. The research recommends a 10–15% replacement range for applications requiring both structural integrity and insulation.
The density of the foam mortar decreased from 1000 kg/m³ for the control mix to 960 kg/m³ at 20% BSA replacement, enhancing the material’s lightweight characteristics. Porosity increased from 24.8% (control) to 30.2% (25% BSA), positively influencing thermal insulation properties. Thermal conductivity measurements indicated a reduction from 0.25 W/mK (control) to 0.18 W/mK at 25% BSA replacement, demonstrating improved thermal resistance. “BSA incorporation improves the pore structure and fosters stronger interfacial bonding within the matrix, especially at 15% replacement,” Mydin noted.
Microstructural investigations using scanning electron microscopy (SEM) revealed that BSA enhances the pore structure and interfacial bonding within the mortar matrix. The water absorption rate increased slightly from 18.2% (control) to 21.6% (25% BSA), but it remains within reasonable bounds for lightweight construction applications.
The study’s findings suggest that BSA can effectively replace ordinary Portland cement (OPC) in LFM, improving its mechanical, thermal, and environmental qualities. “With the results, BSA has shown potential for developing eco-friendly building materials and aiding in reducing carbon emissions in the built environment,” Mydin stated. This innovation could have significant commercial impacts, particularly in the energy sector, where sustainable and energy-efficient building materials are in high demand.
The research highlights the potential of BSA as a green and practical substitute for OPC in lightweight building applications, such as prefabricated panels, insulation layers, and non-load-bearing walls. Its ability to enhance mechanical strength while reducing thermal conductivity makes it a promising material for energy-efficient and sustainable building solutions.
As the construction industry continues to seek sustainable alternatives to traditional materials, innovations like BSA offer a glimpse into a greener future. By leveraging the unique properties of bamboo, researchers are paving the way for more eco-friendly and efficient building practices. This study, published in *Scientific Reports*, underscores the importance of exploring unconventional materials to meet the growing demand for sustainable construction solutions.