This research studies repairing damage to concrete columns with ultra-high-performance concrete using bottom ash and fly ash mixed with Portland cement. The test used cylinder concrete that had been cured for 28 days and burned to simulate a situation where concrete is heated by a fire, which takes 2 hours to burn at 600 degrees Celsius, and then repaired by casting ultra-high-performance concrete around the burned concrete sample, which used the length of the ultra-high-performance concrete that was encased to the length of the sample as 33, 66, and 100 percent. The thickness of the ultra-high-performance concrete layer was 15, 30, and 45 mm.