DETECTING FREEZING AND THAWING DAMAGE IN CONCRETE USING SIGNAL ENERGY

An experimental program was developed to detect freezing and thawing d amage in Portland cement concrete using ultrasonic waves. The ultrason ic measurements were conducted, using the indirect method, at 54 kHz. Signal energy of ultrasonic waves was found more sensitive than ultras onic wave velocity in detection of freezing and thawing damage at init ial stage. However, ultrasonic wave velocity was found more sensitive when the damage is severe. Variations in the power spectra were also u sed to indicate freezing and thawing damage. (C) 1998 Elsevier Science Ltd.