Development of Mycelium-Based Bio-Bricks for Sustainable Construction Materials

The construction industry significantly contributes to global carbon emissions due to the extensive use of energy-intensive materials such as fired clay bricks and ordinary Portland cement (OPC) blocks. This study investigates the development and performance evaluation of mycelium-based bio-composite bricks (MBBs) using rice straw (Oryza sativa) as a sustainable lignocellulosic substrate. The experimental program was conducted at the Materials Research Laboratory, Kumaraguru College of Technology (KCT), Coimbatore. Sterilized rice straw was inoculated with Pleurotus ostreatus, a white-rot fungus known for its lignocellulolytic enzyme activity, and allowed to colonize under controlled conditions before thermal inactivation. The fabricated MBBs were assessed for mechanical, thermal, and physical properties and compared with conventional masonry units. Results indicated compressive strength values of 0.30–0.45 MPa, suitable for non-load-bearing applications. Notably, thermal conductivity ranged from 0.055 to 0.075 W/m·K, demonstrating superior insulation performance compared to traditional bricks. The bricks exhibited ultra-low density (120–180 kg/m³), offering over 90% weight reduction. Microstructural analysis confirmed strong internal bonding through a dense hyphal network. Life Cycle Assessment (LCA) revealed a 91–95% reduction in embodied CO₂ emissions, while biodegradation tests confirmed complete decomposition within 45–60 days. The findings highlight the potential of mycelium-based bricks as an eco-friendly, lightweight, and thermally efficient alternative for sustainable construction and circular bio-economy applications.