The total amount of waste generated worldwide keeps increasing every day. The requirement for new innovations in construction technology involving sustainable development with very less impact on our environment is the need of the hour. By reusing the construction and demolition waste we can reduce the landfill area required for dumping and hence reduce its environmental footprint. In the present research, experimental work has been carried out on a mixture of clay & construction-demolished brick waste (DBW). The demolished brick waste was divided into three size ranges i.e.; coarse, medium, and fine. The unconfined compressive strength of the mixtures was determined at their corresponding optimum moisture content. The results showed that at 20% substitution of clay by DBW, the mixture containing coarse DBW showed the highest strength. But the mixture containing 20% fine DBW mixed with coromandel clay had the highest maximum dry density compared to coromandel clay. This shows how the gradation of DBW has a significant impact on the unconfined compressive strength of the mixture. This study can be a guide in choosing proper subgrade material for roads.