Investigation into a Long-Term Interlayer Bonding of Asphalt Pavements

Development of a framework for standardisation of interlayer bond of asphalt pavements

“…The reason for this could be found in the fact that, these layers are composed of larger aggregates and show lower binder content and shear stress therefore mainly depends on the aggregate interlock. That the shear force and stiffness results for slab 1 are generally higher than the ones for slab 2 (although the asphalt design and material is identical) can be attributed to the fact that the slab 1 had been taken 8 years after construction and trafficking (2006). This confirms the findings of other investigations by Raab and Parti which showed that there is an increase of shear force and stiffness in case of intact and well designed pavements after trafficking (Raab andParti, 2008, Raab and…”

“…This finding is still logical since a decrease in max. shear force and stress of aged pavements is not necessarily combined with decreasing stiffness (see also Raab and Parti, 2008). The increase of shear stiffness and shear reaction modulus with decreasing ADT also corresponds to the findings for shear force and shear stiffness.…”

“…The findings for the average daily traffic, the percentage of heavy vehicles and the age are in agreement with practical experience. The results in a paper by Raab (Raab and Parti, 2008) clearly states that while the shear force of intact pavements increases with age, very high levels of daily traffic and high percentages of heavy vehicles can lead to pavement deterioration combined with a decrease in shear force and shear stress. In this investigation it was found that very high levels of daily traffic and high percentages of heavy vehicles can cause damage to the pavement, which results in a decrease of shear forces and stresses mainly in the wheel path.…”

Comparison of Interlayer Bond Behavior Due to Ageing

“…This device is more versatile in geometry and more defined in the clamping mechanism (Raab and Partl 2008) than the original Leutner device. It has a gap width of 2 mm between the shearing rings.…”

“…Given this situation, the question of how bonding properties develop over time is of special interest especially in cases where interlayer bonding requirements are not met. Some recent investigations on long term performance of bonding properties of tack coats have indicated that ageing can have a positive effect on the bonding properties (Canestrari et al 2013;Raab and Partl 2008;Sutanto 2009). …”