Warm mix asphalt : Mechanical performances assessment and bonding quality measurement by thermal contact resistance

Sâannibè Ciryle Some (1) , Didier Delaunay (2) , Vincent Gaudefroy (1)

1 IFSTTAR/MAT - Département Matériaux
2 LTN - Laboratoire de thermocinétique [Nantes]

The classical asphalt mix manufacturing commonly requires the heating and the complete drying of aggregates. The induced energy cost has opened the way to develop alternatives processes with low energy/ carbon materials such as Warm Mix Asphalt (WMA). Their manufacturing requires specifics techniques to achieve similar performances than Hot Mix Asphalt (HMA). However, manufacturing temperature reduction can locally lead to incomplete aggregate coating by bitumen, although the coating quality measurement remains a challenge. This paper deals with modulus and fatigue performances of some bituminous mixtures manufactured at warm temperatures according to WMA processes in comparison with HMA. In addition, the binder has been extracted from asphalt and complex modulus has been studied. In a second step, an innovative thermal approach based on experimental and numerical method was studied. This approach is based on the Thermal Contact Resistance (TCR) assessment at the interface between the binder and the warm aggregate at the manufacturing step. This TCR is proposed as a coating quality indicator measurement. Our studies have shown that bonding quality depends on bitumen and aggregate temperatures during the contact. The higher the temperature, the lower the TCR and the better the bonding quality. Moreover, we found that TCR value is influenced by additives to modified bitumen properties.

Mots clés: ADDITIF; COLLAGE; MODULE COMPLEXE; ENROBE

Domaines: Matériaux

Sâannibè Ciryle Some, Didier Delaunay, Vincent Gaudefroy. Warm mix asphalt : Mechanical performances assessment and bonding quality measurement by thermal contact resistance. 5th Eurasphalt & Eurobitume Congress, Jun 2012, Istanbul, Turkey. 13p. ⟨hal-00850911⟩