Application of attenuation of resonant frequencies for characterisation of alkali-silica reaction

Authors: E.K. Fischboeck, H. Harmuth, S. Eberl
Paper category: conference
Book title: Concrete Durability and Service Life Planning – ConcreteLife’09
Editor(s): K. Kovler
Print ISBN: 978-2-35158-074-5
e-ISBN: 978-2-35158-085-1
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 196 – 203
Total Pages: 8
Language: English

Abstract: Aim of this study was to investigate whether it is possible to detect ASR-damage with an impulse-excitation technique. For the investigation the Resonant Frequency and Damping Analyzer (RFDA) was applied. The investigated properties were the dynamic Young’s and shear modulus and especially the attenuation of flexural and torsional wave. As reactive aggregate greywacke from Lusatia(Germany), which is well known for its reactivity, was used. Concrete samples with five different mixing proportions were prepared and stored in a one molar NaOH solution at 80°C. Corundum was used as reference material. Measurements with the RFDA as well as measurement of expansions were performed at regular intervals over six months. Furthermore, the Damage Rating Index (DRI), a key figure to evaluate the damage degree, was determined to assess the damage also microscopically. It was found that the decrease of dynamic Young’s as well as shear modulus exhibits a linear correlation with the measured expansions. Considering attenuation reactive and non-reactive samples show a completely different behaviour. For the reactive samples significant increases can be observed in the beginning followed by a flattening or a more or less constant progress. Non-reactive samples show a decrease or constant progress of the attenuation. This means that attenuation reacts sensitive to the damage at an even earlier stage than dynamic Young’s and shear modulus, which basically reflect the results from expansion measurement. It is therefore concluded, that properties determined with RFDA, especially attenuation are very suitable means to detect ASR damage.

Online publication: 2012-05-16
Publication Type: full_text
Public price (Euros): 0.00