Development of a Mineral Binder for Wood Wool Acoustic Panels with a Reduced Carbon Footprint

TL;DR

This paper introduces a new eco-friendly binder for acoustic panels that reduces carbon emissions while maintaining strong mechanical properties.

Contribution

The study develops a sustainable mineral binder system with improved mechanical performance and reduced carbon footprint for wood wool acoustic panels.

Findings

The GCP binder system achieved synergistic improvements in flexural and compressive strengths by nearly 50%.

The GCP system has a carbon footprint of 5.644 kg CO2 eq., significantly lower than magnesium chloride and white Portland cement systems.

Adding metakaolin and liquid glass enhanced mechanical properties and dimensional stability of the binder composites.

Abstract

The construction industry’s reliance on Portland cement (PC) significantly contributes to global CO2 emissions, driving the search for sustainable binder alternatives. This study develops and evaluates novel mineral binder systems for wood wool acoustic panels with a reduced carbon footprint. Alternative binders, including calcium aluminate cement (CAC), magnesium oxychloride cement (MOC), and gypsum–cement–pozzolan (GCP) hybrids, were combined with additives such as metakaolin and liquid glass. Mechanical testing demonstrated that 20–30% metakaolin and liquid glass composites achieved flexural strengths of up to 2.65 MPa and densities above 490 kg/m3. The GCP system showed synergistic improvements in flexural and compressive strengths by nearly 50%, along with enhanced dimensional stability and water resistance. Life cycle assessment indicated substantial CO2 emission increases, particularly for the MOC and CAC formulations, compared to conventional Portland cement-based panels. The carbon footprint of the binder system consisting of GCP is approximately 5.644 kg of CO2 equivalent per functional unit compared to magnesium chloride binder systems, which reach up to 10.84 kg CO2 eq., and white Portland cement systems, which are around 6.19 kg CO2 eq. The three-component GCP binder system offers the best balance of mechanical performance and minimised environmental impact. Key raw material contributors to the ecological load are cement (various types), MgO, MgCl2, and metakaolin, highlighting the importance of optimising binder formulations to reduce carbon emissions. The GCP system, in particular, demonstrates unprecedented synergistic improvements in flexural and compressive strengths, dimensional stability, and water resistance while minimising CO2 emissions. Current work sets a new benchmark for sustainable building materials by offering an eco-innovative pathway towards low-carbon, high-performance wood wool acoustic panels, aligning with global decarbonisation goals.

Figures