Determination of viscoelastic properties from the indirect tensile stiffness modulus (ITSM) test

Title: Determination of viscoelastic properties from the indirect tensile stiffness modulus (ITSM) test
Author(s): A. C. Collop, G. D. Airey
Paper category : conference
Book title: Sixth International RILEM Symposium on Performance Testing and Evaluation of Bituminous Materials
Editor(s): M. N. Partl
Print-ISBN: 2-912143-35-7
e-ISBN: 2912143772
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 324 - 330
Total Pages: 7
Nb references: 8
Language: English

Abstract: This paper describes a method for determining viscoelastic material properties from the Indirect Tensile Stiffness Modulus (ITSM) test undertaken using the Nottingham Asphalt Tester (NAT). A number of viscoelastic material idealizations have been fitted to ITSM results and the effects of the order of the viscoelastic model (ie the number of elements), and the details of the load pulse (rise time, number of load pulses utilized in the fit) have been investigated. Results indicate that the use of a model comprising a Maxwell element in series with two Voigt elements can yield unrealistic and more variable fitted viscoelastic parameters compared to fitted viscoelastic parameters from the simpler model comprising a Maxwell element in series with one Voigt element. The fitted viscoelastic parameters for the model comprising a Maxwell element in series with one Voigt element have been found to show a slight dependence on the rise time in the ITSM test. Results also indicate that the fitted elastic bulk and shear moduli tend to be slightly lower and the shear viscosity and time constants tend to be slightly higher in the case where 5 consecutive load and deflection pulses have been used in the fitting procedure rather than single load and deflection pulses.

Online publication: 2003-03-02
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143772.040