**Abstract:**
Crushed concrete is a construction and demolition waste that causes environmental pollution. The reused of crushed concrete as aggregate in new concrete mix has been common practice in many countries. As a result it is a necessary to determine the behavior of crushed aggregate used in concrete production. This project reports the results of an experimental study on the properties of crushed aggregate concrete compared to natural aggregate concrete and investigating the effect of two different old concrete properties (M1 & M2) on producing new concrete.It was found that, average dry bulk specific gravity of natural coarse aggregate was 2.73%, average of bulk Specific gravity was 2.75 and water absorption was 0.449%. On the other hand, average dry bulk specific gravity of crushed coarse aggregate was 2.46 for M1 and 2.4 for M2. The average bulk specific gravity of crushed aggregate was 2.6 for M1 and 2.54 for M2. Crushed coarse aggregate water absorption was 5.8% for M1 and 6.2% for M2. For water content the average percentage was 2.24% for crushed aggregate for M1 and 2.78% for M2. However it was 0.13% for natural aggregate. The slump results show that slump was higher at 100% and lower at 0% replaced crushed aggregate.The effects of replaced aggregate percent on compressive strength shows that the compressive strength decrease with increasing the volume of crushed aggregate that has been used in the mix.

**Keywords:**
Technical Evaluation, Novel Concrete, Compressive Strength, Slump, Physical Properties, Trial Mix, Recycled, Aggregate.