Comparing Linear Viscoelastic Properties of Asphalt Concrete Measured by Laboratory Seismic and Tension-Compression Tests

Seismic measurements and conventional cyclic loading have been applied to a cylindrical asphalt concrete specimen to compare the complex modulus and complex Poisson's ratio between the two testing methods. The seismic moduli and Poisson's ratio have been characterized by optimizing finite element calculated frequency response functions to measurements performed at different temperatures. An impact hammer and an accelerometer were used to measure the frequency response functions of the specimen which was placed on soft foam for free boundary conditions. The cyclic loading was performed by applying both tension and compression to the specimen while measuring the displacements in the axial and radial direction. The Havriliak-Negami and the 2S2P1D model have been used to estimate master curves of the complex modulus and complex Poisson's ratio from the seismic and the tension-compression tests. The seismic measurements performed at a lower strain level than the tension-compression test give a higher absolute value of the complex moduli (e.g. at 100 Hz) and a lower phase angle compared to the tension-compression results.