Sustainable Use of Construction Waste: Fire Resistance and Strength Characteristics of Recycled Aggregate Concrete for Sustainable Concrete

Abstract

The pursuance of sustainability in construction has propelled the adoption of innovative materials, with recycled aggregate concrete (RAC) emerging as a pivotal solution to address the environmental challenges posed by traditional concrete. Sustainability in construction has become a global priority, driven by the need to reduce environmental impacts and conserve natural resources. The increasing use of green building certifications like LEED and BREEAM highlights the push towards innovative materials, including RAC. With construction and demolition (C&D) waste accounts for 31% of Europe's total annual waste and global consumption of natural aggregates (NAs) projected to double in the coming decades, recycling concrete waste into recycled concrete aggregates (RCA) has emerged as a sustainable alternative. Studies show that RCA use can reduce greenhouse gas emissions by 65% and non-renewable energy consumption by 58%. Despite advancements in RAC research, challenges remain, particularly regarding its performance under extreme conditions like fire. This study investigates the mechanical and durability properties and potential of using recycled aggregate(RA) in conventional concrete as a replacement in varying percentages of recycled fine and coarse aggregates (0%, 25%, 50%, 75%, and 100%) after exposure to different elevated treatment temperatures (20, 100, 200, 300, 400, 500, 600, and 800 °C). The findings aim to address gaps in understanding the thermal behavior of RAC and promote its adoption as an environmentally friendly construction material.