Performance characteristics of epoxy asphalt paving material for thin orthotropic steel plate decks

ABSTRACT

Early pavement distress caused by heavy traffic is frequently observed on bridges with relatively thin decks of orthotropic design, particularly in hot climates. This study investigates the possible use of epoxy asphalt to stiffen the thin deck/pavement composite, minimise deflection and ultimately fatigue failure. Three different epoxy asphalt binders were used and two pavement mix designs were employed. The binder and pavement mixture properties were evaluated by direct tensile and pull-off strength test on the binder, Marshall test of the paving mixture and flexural fatigue tests of paving mixture on steel plates. Test results show that a relatively high modulus binder and a relatively stiff pavement can effectively reduce the composite’s deflection and improve fatigue resistance on a relatively thin steel plate. Binder adhesion to the aggregate in the composite seems to play a pivotal role and the strength of this bond may have a close relationship with the stiffness of the pavement.

KEYWORDS:

• Thin orthotropic deck
• fatigue resistance
• adhesion
• stiffness
• epoxy asphalt