SUITABILITY OF THE ULTRASONIC METHOD FOR TESTING THE INJECTION CONDITION OF PRESTRESSED MEMBERS

EIGNUNG DES ULTRASCHALLVERFAHRENS ZUR UEBERPRUEFUNG DES VERPRESSZUSTANDES VON SPANNGLIEDERN

BY SENSING TESTS ON SAMPLES UP TO 20 M LONG AND ON CONCRETE SAMPLES, THE LIMITS OF APPLICATION OF THE ULTRASONIC REFLECTION AND SOUNDING METHOD WERE DETERMINED. THE REFLECTION METHOD CAN BE USED WHEN THE PRESTRESSING MEMBER IS UP TO 30 M LONG, BUT PROVIDES ONLY APPROXIMATE INFORMATION ON DEFECTIVE AREAS IN THE INJECTION MORTAR AND THE SIZE OF CRACKS IN THE PRESTRESSING BARS.