Linear Viscoelastic Behaviour of Geogrids Interface within Bituminous Mixtures

Recently, the use of geogrids as bituminous pavements reinforcement has increased in pavements construction and rehabilitation, mainly to avoid reflective cracking. One major research topic is to characterize the mechanical behaviour of actual reinforced pavement structures, from laboratory experimentation and take it into account for the design. This paper aims at presenting a methodology for the determination of the Interface Linear Viscoelastic (LVE) behaviour of specimens reinforced with geogrids. This method is based on a tension-compression test on cylindrical sample, classically used for complex modulus tests. A geogrid produced by Texinov was glued with tack coat, which constitute the studied interface. This geogrid is composed by fiberglass filaments and polyester veil, both coated with emulsion. Axial cyclic tests at controlled strain mode of loading (tension-compression) were performed on the same bituminous mixtures samples with and without geogrid. The experimental data was fitted using the 2 Springs, 2 Parabolic Elements and 1 Dashpot (2S2P1D) model both for the mixtures and for the interface. The results indicate that the proposed methodology can successfully provide the interface LVE behaviour.