Identification of the viscoelastic properties of an asphalt mixture using a scanning laser Doppler vibrometer

Estimating the master curve of the complex modulus of asphalt mixtures is essential for high quality and sustainable mixture and pavement design. There are multiple standard methods to estimate this master curve using hydraulic-pneumatic testing machines. These methods are complex to perform, need expensive equipment, and have constraints over the geometry of the testing samples. Therefore, the investigation of alternative methodologies to overcome these issues is of importance. In this research, an experimental setup coupled with a back-calculation technique is developed to identify the viscoelastic properties of an asphalt mixture using an optical measurement system. Using this system instead of traditional transducers eliminates the inaccuracies caused due to the attachment of a transducer to the specimen and allows feasible measurements on multiple points of the specimen. The developed method is compared with a standard method and an alternative method based on analytical formulas, and the results exhibit a good level of accuracy at a wide range of frequency and temperature. It is also demonstrated that even though this method can provide the master curve of a specimen with arbitrary geometry, the first natural frequency of the specimen at the highest temperature provides the first data point of the master curve at low frequencies. Therefore, the first natural frequency of the specimen should be considered while selecting the geometry of the test object.

Jaar van publicatie:2020

Trefwoorden:A1 Journal article

BOF-keylabel:ja

Toegankelijkheid:Open