Factors effecting the shearing strength of bond coat of asphalt surfacing on concrete bridge deck

The paper identified and evaluated factors effecting the shearing strength of bond coat of asphalt surface on concrete bridge deck. Three types of bonding materials were evaluated including cationic polymer bitumen emulsion (CRS-1P), epoxy bitumen (BE), and two-component epoxy resin (Hyper Primer - HP). Temperature was found the most impactive external factor while moisture combined with repeated load is less. Bonding material also is key impacted factor. CRS-1P which is usually used in Vietnam for bond coat on concrete deck could work in normal conditions at 30 degC but fully be fail of zero strength at 60 degC while Epoxy Bitumen (BE) still works with remaining strength of only around 20%. Epoxy Bitumen also has higher shearing strength at 30 degC compared with CRS-1P, from twice to five time depends on the testing condition. Repeated load and moisture which are simulated by wheel tracking test of 7,500 loading cycles at 50 degC to reduce shearing strength in almost testing cases. In general, texturing brings benefit to increase shearing strength.