About 50 million m 3 of ready-mixed concrete is produced in the Federal Republic of Germany each year. Roughly 3% of this quantity (i.e. 1.5 million m3) arises as waste concrete, which at the present time is largely disposed of by dumping. Riker (73,74) and Friesenborg et al. (75) describe in detail how fresh waste concrete can be recycled. However, it is beyond the scope of this state-of-the-art report to deal with requirement for recycled fresh waste concrete.