Mix Design and Performance Study of High-Strength Self-Compacting Concrete with Manufactured Sand.

In recent years, research on self-compacting concrete (SCC) has gradually shifted towards high-strength development, while high-strength self-compacting concrete has been widely used in applications such as precast bridge components and high-rise building projects. Using manufactured sand as an aggregate can effectively address the challenges posed by the depletion of natural sand resources. This study optimized the mix design for high-strength self-compacting concrete with manufactured sand (MSH-SCC) and explored the effects of the fine aggregate replacement rate, sand ratio, and maximum particle size of coarse aggregate on the performance of MSH-SCC. The results indicated that the optimized mix designs for various strength levels met the performance requirements. The fine aggregate replacement rate and the maximum nominal aggregate size significantly affected the workability of the concrete, while variations in the sand ratio had a smaller impact. The yield stress of the MSH-SCC showed a positive correlation with the fine aggregate replacement rate and the maximum nominal aggregate size, whereas the plastic viscosity reached its maximum value under specific conditions. Additionally, the mix design parameters had a limited effect on the mechanical strength of the MSH-SCC. This study provides a scientific basis for the design of high-strength self-compacting concrete with manufactured sand, contributing to the promotion of manufactured sand use and advancing low-carbon development in the construction industry.