| Summary: | 碩士 === 逢甲大學 === 土木工程所 === 97 === In this thesis, a series of experimental investigations are conducted to study the retrofitting behavior of fire-damaged high strength concrete specimens with post-fire-curing. A total of 121 cylindrical concrete specimens is made. The specimens are exposed to different fire environments (600 ﾟC, 800 ﾟC and 1000 ﾟC). They are then re-cured in the air or water for different curing ages (8, 15, 30,90 and 180 days). The residual wave speed in concrete is measured by the impact-echo method for each specimen. All specimens were tested under uni-axial compression after post-fire-curing. The recovery of the residual strength and wave speed are investigated for each curing condition.
The results indicate that the strength recovery of high strength concrete is somewhat different from that of normal concrete after post-fire-curing. The experimental results of air curing show that the residual strength of specimens exposed to 600 ﾟC decreases first at the beginning of curing, rises at 30 days of curing and then gradually
decreases with curing age. While the strength recovery is not apparent for specimens exposed to 1000 ﾟC, no matter what curing age is. The results also show that the strength recovery of specimens with water curing is not related with the curing age. However, the recovery of the residual wave speed is pronounced for specimens with water curing. Besides, the relationship between the residual strength
and wave speed of specimens for each curing condition is well correlated.
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