Comparative analysis of bio-based insulation materials with low-carbon binders: Mechanical, hygrothermal, and durability performance

The construction industry is known for its significant impact on global energy consumption and CO₂ emissions, so there's a growing need to explore sustainable building materials. In this study, we explored bio-based insulation materials made from hemp and miscanthus shives combined with low-carbon binders such as natural prompt cement (NPC) and air lime (CL90-S). We evaluated four different formulations, looking at their physical, mechanical, thermal, moisture control, and durability properties to assess their potential for use in energy-efficient buildings. Our results show that the hemp-based insulation with NPC (C100H) offers the best performance in terms of thermal insulation (λ = 0,12 W/m.K) and compressive strength (0,81 MPa), making it the most efficient in both thermal and mechanical properties. On the other hand, the miscanthus-based formulations perform better when it comes to moisture regulation. Specifically, the L100M formulation showed the highest water vapor permeability (6,38 × 10⁻¹⁴ kg/m³) and the best resistance to freeze-thaw cycles. These findings highlight the role of bio-based materials and low-carbon binders in reducing CO₂ emissions and improving building sustainability.