The structure of an asphalt construction in conventional highway engineering consists of several layers, which are respectively laid and compacted in succession on the sub-base course that has cooled down already. However, compact asphalt pavements comprise two rolled layers of asphalt with different compositions: the thermal capacity of the lower layer is used during the laying so that the thinner upper layer can be compacted better. A reliable bond between the layers is created without additional spraying while doing so, which results in a compact asphalt laminate. The objectives ofusing compact asphalt pavements are: to improve the prerequisites for compaction; to achieve a reliable bond between the layers as the result of interlocking both layers; to result in better dissipation of shearing forcesarising from the surfacing course; to save particularly high-quality building materials on account of the reduced thickness of the surfacing courseand thus to reduce the costs of construction and maintenance. The customer and contractor both have to note the conditions of compatibility when constructing roadways with compact asphalt. These conditions affect the use of machines and personnel among other things, as well as on the costs and the chosen laying process. This study's objective comprises the fundamentals of compact asphalt technology, the laying of compact asphalt by the 'hot on hot' process, the quality assurance measures that have been proven inpractice during laying and the consideration of economic efficiency with definitive prospects. The 'hot on hot' laying process can be basically separated into two processes: laying with a special finisher and laying with conventional finishers. This paper discusses the technical advantages and disadvantages of the two processes, measures for the quality assurance on building sites, and economic efficiency with respect to reduced construction and maintenance costs for a roadway. For the covering abstract see ITRDE139491.
Abstract