The purpose of this article was to evaluate the mechanical and durability characteristics of Ultra-high-performance-concrete (UHPC). UHPC is defined as concrete with compressive strength exceeding 150 N/mm2 (21,756 psi). UHPC can be fiber reinforced and displays increased mechanical performance and improved durability compared to high-strength concrete. This article presents the influence of curing/exposure conditions and concrete age on several mechanical and durability characteristics of UHPC, such as compressive strength and the static and dynamic modulus of elasticity, and the splitting and flexural tensile strengths. UHPC freezing-and-thawing resistance is also investigated. The results presented in this article show that the specimens attained a compressive strength of approximately 150 N/mm2 (21,756 psi) and a modulus of elasticity greater than 50,000 N/mm2 (7,251,887 psi). The flexural characteristics depended on the fiber addition and the specimen’s dimensions.