Study on Perfectly Bonded Ultra-Thin Whitetopping

Ultra-thin whitetopping is a repair method using concrete for asphalt pavement, whose primary characteristic is to allow the existing asphalt pavement and concrete to perform monolithically as a composite section. The existing asphalt concrete is normally milled to achieve such a bond, but milling can reportedly cause debonding of asphalt and concrete. To achieve higher bond strength, the author investigated the use of waterjet on the milled surface of asphalt concrete prior to placing concrete. This paper reports on the adequacy of the new asphalt surface treatment method and discusses the selection of concrete for ultra-thin whitetopping in consideration of construction conditions in Japan based on tests using a full-scale test pavement by this method. A structural analysis of the composite section was also conducted using the obtained physical property values and loading test results, providing design examples of ultra-thin white topping suitable for Japanese roads.