To build up a recyclable society, the environmental issue of concrete is approached comprehensively with a new technique using aggregate coating. The increase of concrete strength is achieved by 1.2 times using improved coating agent mixed properly with silica-fume and by-product powder. A similar effect is also affirmed even if applied to low-quality aggregate. A recycling performance shows that over 90% of aggregate can be recycled. In conclusion, the technique developed by this study is effective for the use of low-quality aggregate and the recycle of coarse aggregate as well as the solution of the environmental problem of concrete.