Evaluate the potential for smart materials and intelligent systems to transform the future of civil engineering. What are the key characteristics and functionalities of smart materials, such as shape$-$memory alloys, piezoelectric materials, and self$-$healing concrete? How can these materials be integrated into civil engineering projects to enhance structural performance, durability, and maintenance? Discuss the challenges associated with the widespread adoption of smart materials, including cost, scalability, and long$-$term reliability.