Mechanical Properties of Nano-silica Sol Modified Mixed Recycled Aggregate Concrete.

Nano-silica sol was used to modify the recycled brick-concrete mixed aggregate, and then they were used to prepare recycled concrete. The variation of mechanical index was analyzed with the age of recycled concrete. The quantitative relationships between different mechanical indicators were established. SEM images were used to explore the modification mechanism of nano-silica sol. The results showed that the compressive strength of the cubes, splitting tensile strength, flexural strength, and axial compressive strength of the 28-day nano-recycled concrete increased by 13.3%, 4.3%, 2.1% and 19.4%, compared with those of the recycled concrete, respectively. A good correlation between mechanical indices of nano-recycled concrete, the splitting tensile strength and flexural strength are in line with power function. The axial compressive strength and cubic compressive strength are in line with linear function, and the ratio between axial compressive strength and cubic compressive strength is closer to the ordinary concrete. [ABSTRACT FROM AUTHOR]