Final answer:
Roman imperial monuments built using concrete were not entirely comprised of concrete. Some buildings were made from marble, demonstrating the Romans' appreciation for architectural history. Concrete enabled the Romans to build impressive structures with greater efficiency.
Step-by-step explanation:
One characteristic that is not associated with Roman imperial monuments built using concrete is that they were not entirely comprised of concrete. Some buildings, including those made from marble, existed alongside concrete structures. The Romans appreciated the architectural history of the Mediterranean and displayed a mixture of both concrete and marble buildings. Roman architecture was a success story of experimentation and innovation, with concrete enabling the Romans to build taller, more complicated, and quicker structures.