In a significant stride towards sustainable construction, researchers have developed a novel approach to enhance the performance of botanical concrete (BC), a promising eco-friendly alternative to conventional concrete. The study, led by Ren Wei from the Institute of Industrial Science at the University of Tokyo and the Norwegian University of Science and Technology (NTNU), explores the potential of autoclave pre-treatment and high kraft lignin addition to improve the water resistance and dimensional stability of BC, ultimately reducing its carbon footprint.
Botanical concrete, made from a blend of concrete and wood waste, offers a closed-loop recycling solution for the construction industry, which is grappling with the substantial environmental impact of conventional concrete and the escalating volume of construction and demolition waste. However, the material’s poor water resistance and dimensional instability have posed challenges to its widespread adoption.
The research, published in the journal ‘Developments in the Built Environment’ (translated as ‘Advances in the Built Environment’), investigates 12 different autoclaving conditions and varying levels of kraft lignin (KL) addition to optimize the performance of BC. The findings reveal that optimal autoclaving at temperatures between 160 and 180°C for 5 minutes minimized swelling to just 7%, significantly enhancing the water resistance of the material.
“We found that the combined approach of autoclave pre-treatment and high KL addition substantially improved the water resistance of botanical concrete,” said Ren Wei, the lead author of the study. “This is a crucial step towards making BC a viable and sustainable alternative to conventional concrete.”
However, the study also found that while high KL content (>30 wt%) improved water resistance, it reduced the bending strength of the material. This trade-off presents an interesting challenge for researchers and industry professionals to balance the material’s properties for optimal performance.
Moreover, the study conducted a life cycle assessment (LCA) to confirm the carbon-negative potential of the developed BC, identifying key emission hotspots and suggesting further reduction measures. This aspect of the research is particularly relevant to the energy sector, as the construction industry seeks to reduce its carbon footprint and contribute to global sustainability goals.
“The carbon-negative potential of botanical concrete is a game-changer for the construction industry,” said a senior industry expert who wished to remain anonymous. “This research paves the way for more sustainable building materials that can significantly reduce the environmental impact of construction projects.”
The findings of this study highlight the potential of modified BC in sustainable construction and guide the development of environmentally friendly building materials. As the construction industry continues to grapple with the challenges of sustainability, the enhanced performance and carbon-negative potential of botanical concrete offer a promising solution.
The research not only contributes to the scientific community’s understanding of sustainable building materials but also provides valuable insights for industry professionals seeking to adopt greener practices. As the world moves towards a more sustainable future, the enhanced performance and carbon-negative potential of botanical concrete offer a promising solution for the construction industry.