When concrete is exposed to high temperature, its properties will deteriorate. Clarifying the property recovery extent of fire-damaged concrete and influencing factors, and developing improvement technology of property recovery are importance issues for repairing and strengthening concrete structure after suffered a fire. In this study, a series of concrete specimens with water-cement ratios of 50% and 35% were heated in an electric furnace at an elevated temperature in a range of 200-750°C. The recoveries of compressive strength, elastic modulus, and carbonation resistance after heated were investigated. We discussed the effects of strength grade of concrete before heated, heating temperature, cooling method, and recurring method and period on the recovery extents. Also, a kind of impregnating agent was used to improve the recovery extents. The experimental results clearly indicated that the use of impregnating agent could greatly promote the property recovery of heated concrete.
