Today, local highway departments are faced with the challenge ofdesigning asphalt pavements for heavy truck loads and high tire pressures using traditional design methodologies that lack the necessary tools to account for these modern situations. Large-stone asphalt mixtures (lsams) are gaining popularity among highway agencies that are charged with designing heavy-duty asphalt pavements. High resistance to deformation in these mixes makes them attractive candidates for construction in heavy-truck traffic routes. As a pavement layer, lsam develops strength by the stress-bridging effect and stone-to-stone contact. Several unique features about lsam exist that make their construction more of an art than a science. Problems with lsam are discussed, including segregation, poor compaction, low density, and particle crushing. Each can be avoided during large-stone-mix construction provided that appropriate countermeasures are used. Specific recommendations for large-stone-mix construction and quality improvement are given on the basis of kentucky's experience with lsam construction. This paper appears in transportation research record no.1282, Transportation construction 1990.
Abstract