Study on Effects of Yellow River Sedimentary Sand on Mechanical and Durability Properties of Fly Ash Concrete
The long-term accumulation of sedimentary sand in the Yellow River Delta negatively impacts the ecological environment and flood control safety downstream.By partially replacing manufactured sand with Yellow River sedimentary sand in the production of large-volume fly ash concrete,the macroscopic properties of the concrete can be improved,which is significant for reducing environmental pollution and promoting resource utilization.The effects of various replacement rates of Yellow River sedimentary sand on the mechanical properties and durability of large-volume fly ash concrete are examined.Results indicate that as the replacement rate of Yellow River sedimentary sand increases,the mechanical properties of concrete initially improve and then decline.The strength reaches its peak at a 10%replacement rate and achieves the strength level of natural aggregate fly ash concrete at a 20%replacement rate.Additionally,when the replacement rate exceeds 20%,the shrinkage rate of fly ash concrete rises,and the relative dynamic elastic modulus decreases significantly,with excess sedimentary sand adversely affecting shrinkage and frost resistance.These findings provide a theoretical foundation and scientific support for the application of Yellow River sedimentary sand in fly ash concrete.
Yellow River sedimentary sandreplacement ratefly ash concretemechanical propertydurability