MATERIALS CHARACTERIZATION AND ECONOMIC CONSIDERATIONS OF COLD-MIX RECYCLED ASPHALT PAVEMENTS (MIX-DESIGN, GUIDELINES, ANALYSES, BITUMINOUS, INDIANA)

Recycling of asphalt pavements has become a common rehabilitation and maintenance process since the mid 1970s. The state of the art of designing and constructing pavements composed of recycled materials has now advanced to a point where recycling is considered as an alternative to conventional procedures for most paving projects. An in-depth evaluation of cold-mix recycling techniques was undertaken and the findings are presented in this report. The variability of the existing materials found in city streets and county roads throughout the State of Indiana was evaluated by means of laboratory test procedures. The data obtained from these experiments were statistically analyzed and the results were examined and discussed in an attempt to characterize those pavements. The significance of various factors believed to influence the final performance of cold recycled mixes, was determined by means of extensive sampling of various types of asphalt pavements from counties and cities within the State. Reclaimed asphalt pavement materials (RAP), with asphalt contents, aggregate gradation, recovered asphalt penetration and viscosity properties, etc., closely resembling values obtained from field-core samples, were used in the laboratory in a series of mix design procedures. These laboratory studies were performed in an attempt to determine the effects that factors such as mixing water, recycling agent content, gradation of the RAP, curing time, etc., will have on the performance of cold recycled mixes produced with existing asphalt pavement materials from Indiana\u27s county roads and city streets. A detailed analysis and discussion of the main factors that affect the selection and implementation of urban and rural pavements cold recycling, is presented by means of information and findings reported in the literature. A set of guidelines for cold-mix recycling of county roads and city streets asphalt pavements in Indiana, is recommended with the objective of directing and informing county and city engineers of the advantages and disadvantages and potential applications associated with asphalt pavement cold-mix recycling