Use of discarded aluminium foil in cementitious material as fire retardant - An experimental study

Minimal greenhouse gas (GHG) emissions and lower fuel consumption are critical aims for current manufacturing industries. The construction industry is indisputably responsible for 11% of global carbon dioxide (CO₂) emissions, including 5% of CO₂ from the cement industry. Alkali-activated cement (AAC) was introduced in the early 1980s to reduce GHG emissions and unsustainable energy requirements. However, the properties of AAC are still being improved with the addition of different supplementary cementitious materials. In addition, manufacturing industries aim to utilize waste materials in order to reduce environmental pollution and landfill. Therefore, to meet both needs, this study focuses on the utilization of waste material to improve the mechanical properties of AAC. Rice husk ash (RHA) is a familiar alternative silica source and its role as a fire resistant up to 600 °C is shown in this study. Discarded aluminium (Al) foil enhances the compressive strength of RHA-based samples by 80% and acts as setting retarder and fire retardant. Emission and cost analyses show that the production of Portland cement emits as much as 125% more CO₂ and costs 1.5 times as much as RHA-based composite. Overall, Al-RHA-based cement production reduces issues related to GHG and waste utilization, and its production emits hydrogen gas as a by-product, a future fuel source, equivalent to 3% of global annual hydrogen demand.