Thermassa – Sustainable Thermal Biocomposite from Construction Waste

Improper disposal of construction waste is a persistent and under-addressed environmental challenge, particularly regarding the fine powder residues generated during wall finishing processes such as sanding of wall putty. This dust, rich in mineral fillers and synthetic binders, is produced in large quantities on construction sites but lacks a structured reuse or disposal pathway. As a result, it is commonly discarded in open areas or drainage systems, contributing to soil alkalinization, water contamination, air pollution, and increased exposure of construction workers and nearby communities to inhalable particulate matter.

This challenge was identified through direct observation. Growing up in a family connected to residential construction, the project’s author witnessed the routine disposal of this material on job sites where his father worked as a professional painter. The absence of sustainable alternatives raised a fundamental question: could this overlooked residue be transformed into something useful, rather than remaining an environmental and health liability?

At the same time, the author’s educational trajectory provided a broader social perspective. Having studied for many years in public schools and later attending a private school through a merit-based scholarship, he observed that educational inequality extends beyond teaching quality to include infrastructure conditions. One of the most evident disparities is thermal comfort. During periods of extreme heat, many public schools rely on minimal ventilation for overcrowded classrooms, while better-funded institutions benefit from adequate thermal insulation and air-conditioning. Scientific studies have already shown that excessive heat negatively affects concentration, learning outcomes, and overall well-being.

Climate change has intensified heat waves, making this infrastructural gap even more critical. Many public schools and community buildings lack affordable solutions for thermal regulation due to budget constraints, reinforcing social and environmental inequalities. This context reveals a clear gap between waste generation, environmental responsibility, and social needs.

Addressing this challenge requires solutions that simultaneously reduce environmental pollution, protect public health, and improve learning conditions. It also calls for approaches rooted in real-world observation, capable of transforming undervalued waste into functional materials that contribute to passive thermal comfort, especially in vulnerable communities.

Thermassa is a bio-composite material under development that proposes transforming construction waste generated during wall finishing processes into a functional, low-cost passive thermal solution for buildings. The project combines fine powder residues from wall putty sanding with natural sugarcane fibers, creating a composite material designed to improve indoor thermal comfort while reducing environmental pollution and material waste.

The project follows an applied engineering research approach. Construction waste residues will be collected from real job sites and prepared through drying and particle size standardization. Natural fibers sourced from local agro-industrial residues will be processed and incorporated into different material formulations. Multiple combinations of mineral residue, fibers, and binding agents will be tested to evaluate workability, mechanical behavior, and thermal performance.

The selection of sugarcane fiber followed a scalability and territorial viability assessment. The project initially considered different natural fibers as potential reinforcements for the composite. Sugarcane fiber was chosen due to its local abundance in the region, ease of access through nearby agricultural and industrial activities, and its cellulose-rich structure, which suggests potential thermal insulation properties. This choice aligns with principles of sustainable engineering and bio-based material design, increasingly adopted in architecture and construction for their environmental performance and natural aesthetic qualities. The approach also allows future adaptation of the model to other regions using locally available natural fibers.

Preliminary physical and thermal characterization will be conducted through accessible laboratory infrastructure via partnerships with technical schools and universities, including comparative experiments using small-scale simulated environments. To support the experimental phase, the project is in the process of formalizing a partnership with a local technical school (ETEC), which will provide laboratory infrastructure for the preparation of test samples and the initial development of standardized material specimens. This collaboration will enable preliminary mechanical and thermal testing, advancing the project from research planning into hands-on material development.

Beyond material development, Thermassa is grounded in principles of circular economy and social innovation. By reintroducing construction waste into the production cycle, the project directly supports Responsible Consumption and Production (SDG 12) and Climate Action (SDG 13) by reducing waste disposal, material extraction, and energy demand for cooling. Its focus on improving thermal comfort in public schools aligns with Quality Education (SDG 4), as adequate learning environments are essential for student performance and well-being.

The project also addresses Industry, Innovation and Infrastructure (SDG 9) by proposing an innovative construction material derived from undervalued residues, and Sustainable Cities and Communities (SDG 11) by targeting public and community buildings in vulnerable urban areas. In future stages, Thermassa envisions community-based production and application models, contributing to Decent Work and Economic Growth (SDG 8) through local training, skill development, and income generation.

From an industrial perspective, Thermassa operates at the intersection of construction, manufacturing, waste management, and professional scientific and technical activities. It offers a scalable pathway for transforming environmental liabilities into functional building materials, demonstrating how scientific research, sustainability, and social impact can converge into practical solutions for real-world challenges.

At its current stage, the project has established a structured research and implementation plan. Initial engagement with local paint supply stores has enabled access to sales data that support estimates of construction waste generation. The project has also outlined a future collection and logistics model based on partnerships with construction professionals, promoting proper waste handling and preventing improper disposal.

Additionally, the project has defined a community-based implementation strategy, which includes training construction workers and local residents in waste collection and material preparation, as well as the future formation of cooperatives in vulnerable communities. These cooperatives would be responsible for producing and applying the thermal material in public buildings, particularly schools facing heat stress.

At its current stage, the project has advanced from initial concept to a structured research and development phase. The project has established a clear technical methodology, defined material composition strategies, and identified testing protocols for evaluating mechanical and thermal performance.

Concrete data collection has been initiated through engagement with the largest paint supply store in the city of Limeira, covering major brands such as Coral, Topcolor, and Futura. Sales records indicate approximately 1,280 units of wall putty sold in the most recent month and around 13,000 units sold throughout 2024. These figures provide a realistic basis for estimating the scale of construction waste generation associated with wall finishing activities.

Based on these data, the project is developing experimental methods to determine the average amount of sanding residue generated per unit of material used. This step is essential to quantify residue availability and validate the technical and logistical feasibility of waste collection and reuse.

In parallel, the project has outlined a collection and logistics model based on partnerships with construction professionals and paint supply stores, aiming to prevent improper disposal and promote responsible waste handling. A community-based implementation strategy has also been defined, including future training of local workers and residents and the potential formation of cooperatives in vulnerable communities for material production and application in public buildings, particularly schools affected by heat stress.

Additionally, the project has identified the regional availability of sugarcane residues through nearby agricultural and industrial activities, supporting the selection of sugarcane fiber as a locally abundant and sustainable raw material. Together, these outcomes demonstrate that the project has achieved a solid foundation for experimental validation, scalability, and future real-world application.