Overview of Hot In-Place Recycling of Bituminous Pavements

Abstract

A general definition of hot in-place recycling (HIPR) is provided. The three basic types of HIPR, including multiple-pass and single-pass operations, are described briefly, and their benefits and shortcomings are discussed. Reasons for using HIPR as a tool for rehabilitation of asphalt pavements, along with its limitations, are summarized. The types of pavements that are suitable candidates for HIPR are addressed. Significant results from a telephone survey, conducted in 1992 to determine the extent of HIPR use by state departments of transportation, are discussed. Current HIPR asphalt mixture design philosophy and procedures are summarized. The need for uniform mixture design procedures, construction specifications, and construction guidelines is indicated. Performance of HIPR pavements relative to conventional new overlays is discussed in terms of correcting pavement surface distress, serviceability, structural value, comparative cost, and energy savings. It is pointed out that considerable research is needed to furnish the paving industry with appropriate mixture design procedures (particularly with regard to sample curing), materials and construction specifications, and general construction guidelines.