This speech delves into the intricate post-heated behavior of Ultra-High-Performance Concrete (UHPC), a material increasingly recognized for its superior properties in modern construction. The focus is on understanding how UHPC, particularly when reinforced with steel fibers and polypropylene (PP) fibers, responds to a range of temperatures, extending from ambient conditions up to 1000°C. Tests were conducted to observe changes in the chemical composition and provide detailed insights into the microstructural alterations. The durability performance, compressive strength, and tensile strain hardening behavior of UHPC were also meticulously evaluated, offering a comprehensive view of the material's response to high temperatures. Expanding the scope to a structural scale, the speech will present findings on the seismic behavior of post-heated UHPC columns. In addition to experimental observations, the presentation will introduce suitable finite element models that effectively simulate the seismic
behavior of post-heated UHPC columns. This comprehensive study not only contributes to the existing body of knowledge on UHPC but also opens new avenues for the application of this advanced material in areas demanding high thermal and seismic resilience.