This study presents a liberation process for recycling high-quality coarse aggregates from waste concrete by impacting with steel grits. Considering the mortar liberation ratio and specific energy for the liberation process as well as the water absorption and apparent density of the recycled coarse aggregates (RCA), the effects of impact velocity, impact time, and concrete strength on the quality of the RCA are investigated. The results show that larger impact velocity or longer impact time of the steel grits is advantageous for improving the mortar liberation ratio and the apparent density of the RCA, as well as reducing its water absorption. A high-velocity short-time impact is an efficient way to reduce the specific energy. With regard to the concrete strength, the influence mechanism of mortar liberation is relatively complex, and proper impact velocity and impact time should be chosen to obtain the high-quality RCA under lower specific energy. These results suggest that liberating the mortar by particle impacting can recycle high-quality coarse aggregates from waste concrete.

这项研究提出了一种释放过程，该过程可通过用钢砂冲击从废混凝土中回收高质量的粗骨料。考虑到砂浆的释放比和释放过程中的比能，以及再生粗骨料（RCA）的吸水率和表观密度，研究了冲击速度，冲击时间和混凝土强度对RCA质量的影响。 。结果表明，较大的冲击速度或更长的冲击时间有利于提高砂浆的释放率和RCA的表观密度，并降低其吸水率。高速短时冲击是降低比能量的有效方法。在混凝土强度方面，砂浆释放的影响机理比较复杂，应该选择适当的冲击速度和冲击时间，以在较低的比能下获得高质量的RCA。这些结果表明，通过颗粒撞击释放砂浆可以回收废弃混凝土中的高质量粗骨料。