1. The document discusses using copper slag as a replacement for fine aggregate in concrete. Copper slag is an industrial byproduct generated during copper production.
2. The author reviews past studies that found copper slag can improve the strength and durability of concrete when used to replace up to 50% of fine aggregate. Properties like compressive strength and resistance to sulfate attack were enhanced.
3. However, replacing fine aggregate with more than 50% copper slag resulted in weaker concrete due to increased voids and microcracks in the material. The document concludes that copper slag is a viable partial replacement for fine aggregate in concrete.