Deterioration mechanism of interface transition zone of concrete pavement under fatigue load and freeze-thaw coupling in cold climatic areas

In addition to stresses from dynamic loading, concrete pavements in cold climatic areas are often attacked by freeze-thaw cycling. The interface transition zone (ITZ) is the first section to deteriorate. To study the micro-structure changes of ITZ under the coupling function of fatigue load and freeze thaw cycling, an indoor-accelerated coupling test was designed. The results show that the coupling effect accelerates the deterioration rate and increases the complexity of micro-crack structures with more pores including crack nucleation. Moreover, the coupling effect significantly reduces impermeability. DOD is the main factor that accelerates the speed of permeability attenuation of concrete. (C) 2017 Elsevier Ltd. All rights reserved.