Tridimensional linear viscoelastic properties of bituminous mixtures produced with crumb rubber added by dry process

The influence of the addition of Crumb Rubber (CR) by dry process on the tridimensional linear viscoelastic properties of bituminous mixtures was studied. Advanced complex modulus tests were performed on two bituminous mixtures: a classical one used as reference material and a similar bituminous mixture with 3% of CR (in the mass of the mixture). CR with a continuous 3/6 mm grain size distribution replaced coarse aggregates. Complex modulus and complex Poisson’s ratio were determined from sinusoidal tension/compression loading tests. Experimental data were modelled with the 2S2P1D model. Results show that Time-Temperature Superposition Principle is valid for the mixture containing CR. Similar shift factors were used to obtain master curves of complex modulus and complex Poisson’s ratio of both mixtures. Lower values of norm of complex modulus at high frequencies/low temperatures were found for the mixture with CR. Curves of normalised complex modulus and complex Poisson’s ratio of both mixtures overlap.