The Worldwide consumption of concrete aggregates is approximately 11.5 billion tons per year for the construction of any infrastructures. It has been predicted that more than 2.5 billion tons per year of coarse aggregates are expected to be consumed by the year 2020 for construction purposes. The raw material (i.e., coarse aggregate) used for concrete is becoming costly, depleting day by day, and its production uses a substantial amount of energy. Hence, the recycled aggregate (RA) provides the perfect solution for this growing problem. It can replace the NA to some percentage on road pavement or partial replacement in concrete, which can reduce the depletion of NA resources. RA implementation would also help in reducing landfill costs. Therefore, using these recycled aggregates presents a sustainable solution to the environmental impact at hand. Also, literature says meta-kaolin is a substance that can improve not only the strength of the concrete but the room inside, better than what a natural aggregate consists, which is required for improved freeze-thaw resistance. For this, recycled aggregate has more voids and room inside for the water to expand when it melts inside.
Kanteti, Vineeth 3387428 "Preparation of High Strength Concrete using Meta-kaolin and Investigating its Freeze - Thaw Resistance." (Spring 2017).