Process for improving crack resistance of recycled aggregate concrete

A process for improving crack resistance of recycled aggregate concrete, comprising following steps:

• (1) soaking recycled fine aggregate in an organosilicon compound for modification, thereby obtaining modified fine aggregate;
• (2) soaking recycled coarse aggregate in a silica sol solution, then adding quicklime, thereby obtaining modified recycled coarse aggregate;
• and
• (3) mixing cement, carbide slag, fly ash and an additive with water until uniform, then sequentially adding the modified fine aggregate and the modified recycled coarse aggregate and mixing uniformly, finally performing later-stage curing to obtain the recycled aggregate concrete;
• wherein in the step (1), the recycled fine aggregate is waste brick fine aggregate with a particle size of 0.2-6 millimeters;
• the waste brick fine aggregate has an SiO2 content of 55-61 weight percent and an Al2O3 content of 22-25 weight percent;
• in the step (2), the recycled coarse aggregate is obtained by crushing and screening waste concrete and then mixing with coarse crushed stone, with a particle size of 5-25 millimeters;
• and
• an amount of the water added is controlled to maintain a water-cement ratio of a concrete system within a range of 0.35-0.60 water/cement.