Recycled coarse aggregate modified by silica sol as well as preparation method and application of recycled coarse aggregate

The invention discloses recycled coarse aggregate modified by silica sol and a preparation method and application thereof.The preparation method comprises the steps that the recycled coarse aggregate is immersed in a hydrated sodium silicate solution with the mass concentration of 40%-60% for standing, after soaking is conducted for 9-12 h, soaking is conducted for 5-10 min through a dilute acetic acid solution with the mass concentration of 6%-13%, natural air drying is conducted for 1 h, and pretreated recycled coarse aggregate is obtained; and finally, pouring the pretreated recycled coarse aggregate into a stirrer, and fully stirring the pretreated recycled coarse aggregate with quicklime powder to prepare the silica sol modified recycled coarse aggregate. The invention solves the problems that the surface modification sodium silicate in the existing treatment method has low early strength and can only be coagulated and cured in about 20 days; and low-concentration weak acetic acid is used, so that sodium