The intensified aggregate was obtained by using RPC （reactive powder concrete） grout for strengthening recycled coarse aggregate. The effect of intensified aggregate mixed with recycle aggregate and natural aggregate, mixture of recycle aggregate and natural aggregate and their mixing ratio on compressive strength, splitting tensile strength and flexural strength of recycled concrete was investigated. The test results show that the water absorption of recycled aggregate mixed with aggregate intensified by RPC grout is lower than that of recycled aggregate, the crush index decreases significantly. For the mixture of intensified aggregate and recycled aggregate, the compressive strength of recycled concrete in different ages decreases with the increase of intensified aggregate content, but for the other two mixtures, the compressive strength of different ages increase with the increase of intensified aggregate or recycled aggregates content. And for these two mixtures of intensified aggregate and recycled aggregate, intensified aggregate and natural aggregate, the splitting tensile strength increases with the increase of intensified aggregate content, but for the mixture of recycled aggregate and natural aggregate, the changes of splitting tensile strength and recycled aggregate content is quite complicated, showing a large discreteness. For the mixture of intensified aggregate and recycled aggregate, the flexural strength, on the whole, decreases with increase of intensified aggregate content, for the mixture of intensified aggregate and natural aggregate, the changes of flexural strength with intensified aggregate content is relatively complex, for the mixture of recycled aggregate and natural aggregate, the flexural strength increases with the increase of recycled aggregate content. Compressive strength can well reflect the influence law of the intensified aggregate or recycled aggregate content on the concrete strength. Under the same circumstances, compressive strength is generally lower than the ordinary one, the mixing ratio of all three mixed aggregate is stable at 093. Splitting tensile strength can be better than ordinary splitting tensile strength reflecting the influence law of the intensified aggregate or recycled aggregate content on the concrete strength. Under the same circumstances, the splitting tensile strength is higher than that of the ordinary one basically, the mixing ratio of three mixed aggregate is quite different. The concept is proposed of effective water cement ratio and nominal water cement ratio, the effective water cement ratio is the most important factor to determine strength of recycled concrete. To compare intensified aggregate content how to influence recycled concrete strength, effective water cement ratio of them must stay the same, rather than nominal water cement ratio.