Effect of Bituminous Material Rheology on Adhesion

Bituminous materials are used in many civil engineering applications where adhesion to a substrate is essential for good performance. Yet, it is not possible to predict the adhesion strength of these materials. The particular case of bituminous crack sealants is of interest in this paper, where the effect of sealant viscosity, aging, test temperature and loading rates are investigated by means of a blister test. This test provides the bonding characteristics to a model aggregate in terms of interfacial fracture energy (IFE). From the testing of several sealants, it was found that pouring viscosity affects adhesion and that higher viscosities help to attain higher IFEs. Temperature was found to play a key role on bonding characteristics and failure mechanism because it affects the viscoelastic properties of the sealant. In other words, the glass transition temperature (Tg) was found to have a governing role on bonding characteristics. At temperatures above Tg, bond strength was found to be affected by sealant flow such that failure is flow related, i.e., cohesive failure prevails. At temperatures below the Tg, where sealants are stiff and bulk deformation is low, stress is directed towards the interface so that failure tends to be adhesive. In taking into account temperature and test rates, an IFE master curve was obtained for a sealant. Such curve may be used in predicting and comparing sealant IFE.On s'int\ue9resse au cas particulier des scellants pour fissures bitumineux dans ce document, en examinant l'incidence de la viscosit\ue9, du vieillissement, de la temp\ue9rature d'essai et des taux de charge des scellants au moyen d'un essai de boursouflure. Cet essai permet d'obtenir les caract\ue9ristiques d'adh\ue9rence d'un granulat de contr\uf4le en termes d'\ue9nergie de rupture interfaciale (\uc9RI). La mise \ue0 l'essai de plusieurs scellants a r\ue9v\ue9l\ue9 que la viscosit\ue9 au coulage influait sur l'adh\ue9rence et que des viscosit\ue9s plus \ue9lev\ue9es contribuaient \ue0 donner des \uc9RI sup\ue9rieures. On a d\ue9couvert que la temp\ue9rature jouait un r\uf4le cl\ue9 sur les caract\ue9ristiques d'adh\ue9rence et le m\ue9canisme de d\ue9faillance car laPeer reviewed: YesNRC publication: Ye