초음파속도법(UPV)을 이용한 고온 노출 콘크리트 강도 추정 연구

There are various tests for measuring the strength of concrete structures affected by fire. Actually, one of the most reliable tests is a destructive test using the drilled concrete core samples after fire. The non-destructive testing methods (NDT) such as ultrasonic pulse velocity (UPV) method also may be apply to estimate the concrete strength, especially when there are problems related to obtaining core samples. This paper describes the strength estimation of concrete subjected to high temperatures using UPV (ultrasonic pulse velocity) method. Cylindrical concrete specimens of 18MPa, 24MPa, 27MPa and 35MPa were exposed to 2000C, 4000C, 6000C and 8000C, respectively. Compressive and splitting tensile strengths after exposure to high temperature were investigated using destructive test and non-destructive test (UPV method). Test results indicated that the obtained decreasing rates of concrete strength up to exposure of 8000C by destructive test are very similar to decreasing rates of UPV values. It can be concluded that the UPV method, non-destructive test, can be used to estimate strength of concrete subjected to high temperatures without damage of concrete structural members due to fire damaged core samples.