Abstract: | The utilization of processed rubber and construction waste in lieu of soil as a substrate could improve significantly seismic performance, while addressing the pressing environmental issue of how to reutilize and dispose of, i.e., automotive tires and demolition by-products. In this study, a series of laboratory tests explore the influence of recycled tire waste (RTW) and recycled concrete aggregate (RCA) fine particles on the compressibility parameters of RCA–RTW mixtures. The results revealed that the addition of rubber waste to RCA causes an increase in its compressibility and consolidation index (cv) while prompting a power law decrease in the associated void ratio. It is found that all RCA–RTW mixtures are characterized by higher values of the compression (CC) and swelling (CS) indexes when compared to the pure RCA specimens while presenting a primary and secondary constrained modulus of fewer than 42 MPa and 96 MPa, respectively. |