Mechanical Properties of Railway High-strength Manufactured Sand Concrete: Typical Lithology, Stone Powder Content and Strength Grade

In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure, a series of high-strength manufactured sand concrete (HMC) are prepared by taking the manufactured sand lithology (tuff, limestone, basalt, granite), stone powder content (0, 5%, 10%, 15%) and concrete strength grade ( C60, C80, C100) as variables. The evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are studied. Compared to river sand, manufactured sand enhances the cubic compressive strength, axial compressive strength and elastic modulus of concrete, while its potential microcracks weaken the flexural strength and splitting tensile strength of concrete. Stone powder content displays both positive and negative effects on mechanical properties of HMC, and the stone powder content is suggested to be less than 10%. The empirical formulas between cubic compressive strength and other mechanical properties are proposed.