Nano-SiO2 Recycled Concrete Anti-Sulfate Performance and Damage Mechanism Research

The use of construction waste for concrete is an effective way to reduce the environmental burden while improving sustainability materials. Nano-SiO2 (NS) has excellent volcanic ash activity, which can effectively improve strength concrete. In this study, synergistic effects NS and 30% recycled aggregate (RCA) on mass loss, compressive strength, ultrasonic sound velocity values microstructure RAC after 25, 50, 75 100 repetitions a dry–wet cycle (DWC) sulfuric acid were investigated. results show that significant role in performance. specimens showed lowest loss rate, highest value best resistance sulfate erosion when doping was 4%. Meanwhile, under CT SEM, with lower porosity higher hydration, inhibit crack generation stable volume growth within 0–50 DWC. addition, addition improves not only substrate but also interfacial transition zone (ITZ). When 4% added, durability improvement This study production performance provides strong reference integrated application nanomaterials