ABSTRACT
One of the methods to evaluate concrete material deterioration is to evaluate the propagation behavior of broadband ultrasonic waves. The authors are working on this method to evaluate concrete deteriorated by alkali-silica reaction (ASR).
In this paper, a specimen was prepared using coarse aggregate with ASR, and accelerated curing was carried out on this specimen when compressive stress was applied. It was confirmed that the compressive stress environment restricts the expansion force of coarse aggregate due to ASR, making the test specimen itself denser and improving the propagation behavior of broadband ultrasound. After accelerated curing, it was confirmed that the propagation energy of broadband ultrasound was significantly reduced in the stressreleased state. Similar experiments were conducted on PC girders that were actually deteriorating due to ASR, and it was confirmed that the propagated energy tended to be large in areas where the effect of prestress was large.
