Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Improved impact-echo method for quantification of distributed damage in concrete
The impact-echo nondestructive test method has previously been used for locating distributed damage in concrete, which may be caused by ASR (alkali silica reactivity) or DEF (delayed ettringite formation). However, it has been difficult to obtain reliable results with the conventional approach, which relies on manual operation of the impactor and the use of a log-decrement algorithm to quantify the damage. An improved method based on an automated solenoid impactor has been employed to test various concrete prisms prepared in the lab. Micro-cracks were induced in the prisms using proven techniques for accelerating DEF and ASR in concrete. The parameter used to quantify the damage is the Q-factor, which has the advantage of being independent of the dimensions of the structure. Other resonant frequency based parameters as well as expansion measurements were used to qualify the trends suggested by the Q-factor. The Q-factor was found to identify specimens with induced micro-cracks with good accuracy. Parameters such as resonant frequency and resonant frequency shift were found to corroborate the results of the Q-factor. This paper discusses the results of this experimental program.
Improved impact-echo method for quantification of distributed damage in concrete
The impact-echo nondestructive test method has previously been used for locating distributed damage in concrete, which may be caused by ASR (alkali silica reactivity) or DEF (delayed ettringite formation). However, it has been difficult to obtain reliable results with the conventional approach, which relies on manual operation of the impactor and the use of a log-decrement algorithm to quantify the damage. An improved method based on an automated solenoid impactor has been employed to test various concrete prisms prepared in the lab. Micro-cracks were induced in the prisms using proven techniques for accelerating DEF and ASR in concrete. The parameter used to quantify the damage is the Q-factor, which has the advantage of being independent of the dimensions of the structure. Other resonant frequency based parameters as well as expansion measurements were used to qualify the trends suggested by the Q-factor. The Q-factor was found to identify specimens with induced micro-cracks with good accuracy. Parameters such as resonant frequency and resonant frequency shift were found to corroborate the results of the Q-factor. This paper discusses the results of this experimental program.
Improved impact-echo method for quantification of distributed damage in concrete
Verbesserung des Impact-Echo-Verfahrens zur Quantifizierung von verteilten Schädigungen in Beton
McMorris, Nicolas (Autor:in) / Amde, Amde M. (Autor:in) / Livingston, Richard A. (Autor:in)
2007
10 Seiten, 7 Bilder, 14 Quellen
Aufsatz (Konferenz)
Englisch
Improved impact-echo method for quantification of distributed damage in concrete
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