The surface zone of the recycled aggregate plays a significant role in the strength and durability of concrete. In this research, various concrete series incorporating natural coarse aggregate [NCA], untreated recycled coarse aggregate RCA(UN), mechanical scrubbing treated coarse aggregate...

The strength evaluation of concrete can be determined by destructive and Non-destructive methods. In recent years construction industry initiated using demolition waste in structural concrete and due to this action coarse aggregate cost has been reduced. By using pre-treatment method of recycled coarse aggregate (RCA), the concrete properties will increase. Thus, the RCA are treated by using mechanical scrubbing and acid treatment (H₂SO₄ & HCl) before induced in concrete. Slump value for controlled concrete with river sand and M-sand was 110mm and 100mm. For untreated recycled aggregate concrete, the slump value reduced to 70mm and it is improved by using mechanical scrubbing treated aggregate concrete by 90mm without addition extra water. Similarly, Vee-bee consist meter test and Compaction factor test results were reduced suddenly while using untreated aggregate concrete; it was improved by all treatment methods especially by mechanically scrubbing techniques. The compressive strength for untreated aggregate concrete at 28 days is 16.83 N/mm² and it was improved by mechanical scrubbing by 22.68 N/mm².The strength was increased by mechanically treated aggregate concrete by 25.79% on compared with untreated aggregate concrete. The rebound numbers of treated RAC were improved by 12.5-26.31% at 28 days than RAC (UN). The ultrasonic pulse velocity in different treatments of RAC was improved by 8.17 – 22.82% at 28 days than RAC (UN). Impact resistance also enhanced by using treated recycled aggregate.