Experimental study on the characteristics of unbound granular layer incorporated with recycled materials

Pavement is a multi-layered system in which each layer’s strength is reflected on the pavement. Because of their economic and engineering qualities, various secondary materials like slag, bottom ash, concrete debris, foundry sands, and other waste materials are evaluated for usage as alternatives for natural aggregates or materials in the applications of the civil engineering. The present study evaluates the effect of using waste material (reclaimed concrete aggregate and foundry sand) at a different percentage (5%, 10%, 15%) by weight of base layer on CBR and MR at different soaking periods (4, 14, and 30 days). The results show that CBR and MR values increase as the FS % increased until reached 10% then the effect is reduced while the rate of increase in CBR and MR is small after 10% of RCA. Also, results show that reduced in CBR and MR as increased in soaking periods after 4 days.