As cities continue to grow and temperatures continue to rise, the need for sustainable, energy-efficient construction materials has never been greater. Researchers at BITS Pilani K K Birla Goa Campus, in collaboration with industry and research partners, are working on an innovative solution that addresses two major global challenges, reducing building temperatures and storing carbon within construction materials.
Their latest research focuses on biochar-based cementitious composites, an emerging class of sustainable building materials designed to improve thermal comfort while contributing to carbon sequestration.
A Collaborative Effort Towards Sustainable Construction
This research was carried out through a collaboration between BITS Pilani, K K Birla Goa Campus, Low Carbon Construct Forum (LCCF), M/s Engrow Carbon Energy, and Avant-tech Lab & Research Centre Pvt. Ltd. The initiative was led by Dr. Abhishek Sharma, Professor of Chemical Engineering at BITS Pilani, with overall management from Mr. Vijaykumar Kulkarni, Founder-Director of LCCF.
The team explored how biochar, a carbon-rich material produced from agricultural waste, could be incorporated into cementitious materials to create more sustainable and energy-efficient construction products.
What Is Biochar?
Biochar is a stable, carbon-rich material produced by heating biomass under controlled conditions. In this project, biochar was produced from cashew nut shell waste, converting an agricultural by-product into a valuable resource for the construction industry.
Unlike conventional construction additives, biochar has the unique potential to lock carbon within building materials for extended periods while improving certain performance characteristics.
Developing a Smarter Building Material
The research team developed a lightweight cementitious screed containing biochar and evaluated its performance through a series of laboratory experiments and field trials.
The objective was simple but ambitious:
Improve thermal insulation in buildings
Reduce indoor temperatures
Utilize agricultural waste effectively
Explore long-term carbon storage in construction materials
This innovative approach demonstrates how waste materials can be transformed into high-value products that contribute to a more sustainable built environment.
Promising Results
The study produced several encouraging outcomes.
Researchers successfully developed a biochar-based lightweight cementitious screed with enhanced thermal insulation properties. During a small-scale field trial, the material demonstrated the potential to reduce surface temperatures, highlighting its ability to improve thermal comfort in buildings.
In addition, laboratory trials on biochar-based concrete showed that approximately 6% of the fine aggregate (sand) in M40-grade concrete could be replaced with biochar while maintaining the required fresh and hardened properties specified by construction standards.
These findings suggest that biochar can be integrated into conventional construction materials without compromising structural performance.
Why This Research Matters
The construction sector is responsible for a significant share of global carbon emissions. While reducing emissions remains essential, researchers are increasingly exploring ways to make buildings themselves part of the climate solution.
Biochar-based cementitious materials offer several potential advantages:
Improved thermal insulation
Lower cooling requirements in buildings
Productive utilization of agricultural waste
Reduced environmental footprint
Long-term carbon sequestration within construction materials
Together, these benefits could contribute to more sustainable and energy-efficient buildings while supporting circular economy practices.
Scientific Validation
To ensure the reliability of the developed materials, the final samples underwent testing at the Mahindra–TERI laboratory in Delhi for evaluation against the requirements of ISO 22007-2.
Such validation is an important step toward understanding the material's real-world performance and its potential for broader adoption in the construction industry.
Looking Ahead
While the current results are promising, the research represents only the beginning of what biochar-based construction materials could achieve.
Future work will focus on further evaluating carbon sequestration capabilities, optimizing material performance, and exploring additional applications in concrete and cementitious composites. The collaborating organizations have expressed their commitment to continuing research in this area to support the development of more sustainable construction technologies.
Building a More Sustainable Future
Innovation in construction is no longer limited to stronger or faster materials, it is increasingly about creating buildings that are smarter, more sustainable, and better for the environment.
By transforming agricultural waste into a valuable construction resource, this collaborative research demonstrates how engineering innovation can address pressing environmental challenges while improving the performance of modern buildings.
As the demand for climate-resilient infrastructure continues to grow, biochar-based cementitious materials represent a promising step toward a future where buildings not only consume fewer resources but also contribute to long-term carbon storage and improved thermal comfort.
