Moisture has an important influence on the damage process of asphalt pavements since it mostly leads to a more rapid deterioration. The objective of the presented investigation was to verify findings that moisture has a negative effect on the bond force. Previous studies showed that moisture can lead to a reduction of the mean maximum shear force up to 30% for long term water storage or combined pressure and short term water storage at 40°C tested with the LPDS shear device. Additionally, the influence on maximum shear stiffness was investigated. Furthermore, it was assumed that the reduction of shear properties would increase with higher applied temperature. The investigation was conducted using different up to date pavement structures for urban roads and heavy trafficked motorways. The chosen material represents the actual Swiss construction practise favouring relatively open graded low noise surface courses. The use of urban pavement structures with comparatively thin (30 mm) surface courses further allowed the application of the Shear Box as an additional measure for the shear properties. The results showed that water conditioning at 40°C or 60°C generally has a negative effect on the interlayer shear bond leading to decreases in shear force and shear stiffness. For pavements with an upper layer air void content of about 5 vol-% the largest reduction in shear force and shear stiffness up to more than 30% can be found for a 5 h water conditioning combined with a pressure of 0.05 MPa.

Additional Metadata
Conference 7th International Conference on Maintenance and Rehabilitation of Pavements and Technological Control, MAIREPAV 2012
Citation
Raab, C. (C.), Partl, M.N. (M. N.), & Halim, A.O. (2012). Effect of moisture on interlayer bonding of asphalt pavements. In 7th International Conference on Maintenance and Rehabilitation of Pavements and Technological Control, MAIREPAV 2012.