Evaluation of techniques for enhancing recycled concrete aggregates: Chemical treatment, biological modification and synergistic reinforcement

Abstract

This study compares the effects of three techniques for reinforcing recycled concrete aggregate (RCA): chemical reinforcement, biological modification, and chemical-biological synergistic reinforcement. It evaluates their impact on both RCA and recycled aggregate concrete (RAC), analyzing their economic costs and environmental impacts through a life cycle assessment. The results indicate that composite reinforcement is more effective than individual methods, demonstrating the highest compressive strength and the best resistance to chloride ion penetration when RCA is replaced at a rate of 50%. Chemical reinforcement proves to be more economical, while biological modification shows less environmental impact. However, chemical-biological synergistic reinforcement requires further optimization to reduce both cost and environmental impact. This study offers valuable insights for the development of chemical-biological composite strengthening techniques and suggests avenues for cost reduction in practical applications.