Development of Lightweight Foam Concrete Panels with High Amount of Construction and Demolition Waste

Abstract

The construction sector faces significant sustainability challenges due to its high resource consumption, CO2 emissions, and the environmental impact of building insulation practices. Portland cement, a key industry component, is a major contributor to CO2 emissions, necessitating greener practices to align with global sustainability goals. Lightweight foamed concretes, known for their low thermal conductivity and density, are gaining importance in insulation applications, but their reliance on Portland cement and aggregates raises sustainability concerns. To address this, the use of construction and demolition waste (CDW) as substitutes or binders in building materials is being explored. CDW can reduce the carbon footprint of cement production and improve building energy efficiency, promoting a circular economy in the construction sector. This study focuses on developing non-structural, lightweight building insulation materials using a significant amount of CDW. An eco-hybrid cement was created as the binder phase, and fine recycled concrete aggregate (FRCA) was used as the aggregate phase. The physical, mechanical, and thermal properties of the mixtures were evaluated by varying the content of eco-hybrid cement, FRCA, foaming agent, silica-aerogel, and the water-binder ratio. The research successfully developed an ultra-lightweight green foam concrete with low dry density and thermal conductivity, making it suitable for insulation applications. The incorporation of CDW in these materials enhances sustainability and reduces the environmental footprint, aligning with global sustainability objectives.