Chulalongkorn University researchers have developed “Bio-Responsive Block,” a ventilation block made from mussel shells. Crushing rather than burning mussel shell waste from coastal communities helps reduce carbon emissions. Designed to be both attractive and practical, the product adds value while promoting a circular economy at the community level.
Highlights
· An Innovation Journey That Began with Waste
· Grinding Instead of Burning: A More Sustainable Approach
· Aesthetics and the Perfect Terrazzo Blend
· Ventilation Blocks: A Solution for Thailand’s Climate
· Expanding Knowledge of Ventilation Block Production to Community Enterprises
Along Thailand’s coastlines, millions of kilograms of mussel shells are discarded year after year. Simultaneously, the global construction materials industry is increasingly focused on reducing carbon emissions. Assistant Professor Dr. Runda Aduldejcharas, the Department of Interior Architecture, Faculty of Architecture, and Deputy Director of the Metallurgy and Materials Science Research Institute, Chulalongkorn University, saw the problem as an opportunity and developed the “Bio Responsive Block,” a ventilation block made from mussel shells—both architecturally striking and a practical example of a community-driven circular economy.
An Innovation Journey That Began with Waste
Before the Bio-Responsive Block project began, this innovation started with the doctoral dissertation of Assistant Professor Dr. Runda Aduldejcharas, who was interested in studying golden apple snails and mussel shells as building materials. She developed this into a learning center building with a bamboo structure. This work was so outstanding that it was selected for exhibition at the COP26 in Glasgow, UK, and marked the first step in confirming that “waste” from fishing communities has more potential than the world previously realized.
With research funding from the Faculty of Architecture, Chulalongkorn University, Assistant Professor Dr. Runda initially explored the use of seashells by burning them at temperatures above 1,000°C to produce lime through oxidation. This lime was then used to partially replace Ordinary Portland Cement (OPC) at proportions ranging from 10 to 30%, with compressive strength tested against industry standards. The results showed that higher proportions of seashell-derived lime reduced strength, in some cases falling below acceptable standards.
However, the bigger challenge lay in the process itself. High-temperature burning requires industrial kilns, making it impractical for community enterprises. This constraint prompted a new approach: replacing burning with grinding.
Grinding Instead of Burning: A More Sustainable Approach
“Grinding instead of burning” may sound simple, but its implications run deeper. The shift from high-temperature processing to manual grinding is not just about simplifying production—it enables communities to take full ownership of the process, a central goal of the Bio-Responsive Block project. Industrial burning requires significant energy input, specialized machinery, and ongoing system maintenance, all of which contribute to carbon emissions and higher costs. In contrast, grinding can be done using manual labor or small, widely accessible tools, making it far more feasible at the community level.
However, grinding does have its limitations. The resulting material is less pure than burnt lime, and the process is more time-consuming. However, in the context of community enterprise development, these trade-offs are acceptable. As Asst. Prof. Dr. Randa explains, “Each process adds value to the material, whether it is burned or ground.”
Aesthetics and the Perfect Terrazzo Blend
The heart of the current Bio-Responsive Block lies in the blend of crushed seashells with terrazzo cement, traditionally used for polished stone floors. The difference between the first form, using burnt lime, and the grinding form isn’t just about the formula. But it’s about elevating it from a “building material” to a “high-value decorative material.”
Terrazzo gives the block surface a unique beauty. Made from fresh mussel shells, which are dark green and hard, the crushed and mixed ingredients in various proportions create a surface tone ranging from light to dark brown, giving a natural look. Using no more than 30% terrazzo in the mixture maintains structural strength.
Even though it’s fishing waste, Asst. Prof. Dr. Runda emphasizes that there will be no waste in the production process. Every part of the shell is used in multiple processes. Beautiful shells are selected for the block’s surface, while the rest are crushed into powder and mixed into the material. This design considers every stage, from raw materials to finished product.
The researcher also plans to incorporate auspicious stones, guided by feng shui principles, to appeal to customers who value the color and symbolic energy of materials—adding another layer of meaning to the product.
Ventilation Blocks: A Solution for Thailand’s Climate
Asst. Prof. Dr. Runda recognizes that aesthetics alone is insufficient. All materials must have good thermal performance, especially in Thailand’s climate with year-round high heat and humidity. The ventilation block design allows air to flow through, helping to dissipate heat and improve air circulation within buildings without relying on air conditioning. Furthermore, the ventilation block pattern creates a beautiful interplay of light and shadow, adding vibrancy to the architecture.
Dr. Runda’s design focuses on interior design rather than structural load-bearing, making it ideal for use as a highlight wall in residences, resorts, cafes, or buildings with a focus on nature and sustainability. It doesn’t need to cover the entire wall; selecting specific areas to highlight is sufficient. For exterior use, an appropriate coating will enhance water and sunlight resistance.
In the future, Asst. Prof. Dr. Runda suggests incorporating natural fibers from local plants, such as palm fibers or other plants, into the walls to improve thermal insulation and lower indoor temperatures, further addressing energy efficiency in a hot and humid climate.
Expanding Knowledge of Ventilation Block Production to Community Enterprises
Asst. Prof. Dr. Runda explained the production process, beginning with collecting seashells from the community, washing them, drying them, and grinding them into a fine powder. This powder is then mixed with terrazzo cement in a specific ratio, water is added, and the mixture is kneaded and poured into molds. After drying, the blocks are removed, and the surfaces are polished by hand. The entire production process of the hollow core bricks uses only readily available household tools; no industrial machinery is used. For this research, Asst. Prof. Dr. Runda conducted experiments in her own home before expanding the project to the community.
She encouraged community members with no prior knowledge of materials to participate in the process from scratch to test whether “someone without any prior experience can do it.” The initial results weren’t as aesthetically pleasing as desired, but it clearly demonstrated that the process is transferable, and with proper training, villagers can certainly produce the bricks.
Asst. Prof. Dr. Runda revealed her future goals: to conduct workshops directly with the community to establish an independent community enterprise. This will allow the community to view seashells from a new perspective—not as a problem, but as a valuable raw material that can create value for the community.
The participating fishing communities will gain multiple income streams simultaneously: from selling their existing pickled shellfish, from processing seashells into products, and from welcoming ecotourism. The vision for the future, as envisioned by this lecturer, is a community where tourists can learn about the entire process, from mussel farming and harvesting to processing the shellfish meat and creating products from seashells with their own hands. This is educational tourism that provides both experiential learning and environmental significance.
This model can be expanded to other coastal areas, both in Thailand and internationally, because calcium carbonate isn’t only found in mussel shells; oysters, cherry snails, and clams also have similar potential. Asst. Prof. Dr. Runda stated, “We didn’t design this as a case study for just one community but rather as an inspiration for future implementation.”
Even more interesting than the novelty of this innovation is that it’s not entirely new. “Ancient Thais have used seashell lime to make Buddha images and red lime paste for betel nut chewing for centuries,” she explained. This means that what they are doing is reviving traditional wisdom and adapting it to a modern context, encompassing material technology, design, and the creative economy.
Following the successful implementation of this innovative work, Asst. Prof. Dr. Runda said that the most important thing for her as a researcher and lecturer isn’t commercial success but the pride in sharing her knowledge so others can apply it in practice and create real value. And there is potential for further development.
Bio-Responsive Block may be just beginning, but the story it tells is deeper than a single wall block. It’s about a community that sees value in something once discarded and researchers who refuse to let knowledge remain stagnant on paper but instead create value from natural materials that have long been waiting to be recognized.
Those interested can follow this fascinating innovation by emailing [email protected]
Read more at: https://www.chula.ac.th/en/highlight/303235/
