Evaluation of Field-Produced Hot-Mix Asphalt (HMA) Mixtures with Fractionated Recycled Asphalt Pavement (RAP) - 2007 Illinois Tollway Field Mix Trials

To test the fractionated recycled asphalt pavement (FRAP) materials, the Illinois Tollway, working through its contractors and consultants, developed and conducted a project on the applicability and feasibility of using increased RAP contents through FRAP. The goal of the program was to answer two main questions: ??? Can the Tollway design, produce, and construct high-quality HMA pavements with high FRAP content mixes? ??? Will these materials provide the same or better pavement performance as the standard mixes used by the Tollway and Illinois Department of Transportation (IDOT), and with performance that is consistent with pavement design procedures? In the summer of 2007, a construction contract was awarded for advance pavement work on the Jane Addams Memorial Tollway (I-90) in the Rockford area. The timing, scope, and circumstances of the I-90 project provided a rare opportunity to evaluate several different HMA concepts directly via plant mixing and field trials. This is a summary report of the field trial production mixes containing high quantities of FRAP sponsored by the Illinois Tollway. The results of these field trials show that the Tollway can design, produce, and construct high-quality HMA pavements with high FRAP content mixes. Further, the laboratory evaluation of these mixes shows that their performance is expected to be similar to currently used materials and consistent with current pavement design procedures. The issue of asphalt cement grade bumping was evaluated with the field trials and, based on these results, there is no need to double bump the asphalt cement grade within the design criteria. 17. Key Words 18. Distribution StatementIllinois Center for Transportation (ICT)published or submitted for publicationis peer reviewe

Enhancing pavement performance prediction models for the Illinois Tollway System

Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway) with over 2000 lane miles of pavement utilizes the condition rating survey (CRS) methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT) are used by the Tollway to predict the future condition of its network. The model projects future CRS ratings based on pavement type, thickness, traffic, pavement age and current CRS rating. However, with time and inclusion of newer pavement types there was a need to calibrate the existing pavement performance models, as well as, develop models for newer pavement types.This study presents the results of calibrating the existing models, and developing new models for the various pavement types in the Illinois Tollway network. The predicted future condition of the pavements is used in estimating its remaining service life to failure, which is of immediate use in recommending future maintenance and rehabilitation requirements for the network. Keywords: Pavement performance models, Remaining life, Pavement managemen

Evaluating Pavement Markings on Portland Cement Concrete (PCC) and Various Asphalt Surfaces: Results of Year 1, 2, 3, and 4 Data Collection (Includes Illinois Department of Transportation Pavement Marking Guide)

The Illinois Department of Transportation (IDOT) uses a variety of different pavement marking systems and has experienced a wide range of pavement marking performance. In an effort to maximize marking performance and to optimize marking selection, IDOT initiated a research project to evaluate the performance of all currently approved marking types to develop a pavement marking selection guide based on performance results. The purpose of this project is to evaluate the performance of pavement markings on both portland cement concrete (PCC) and hot-mix asphalt (HMA) pavements over a period of four years. Field investigations were conducted to gather data on the durability and visibility of markings and the compatibility between markings and pavement materials. From the results of the study and a life-cycle cost analysis, Applied Research Associates (ARA) developed a pavement marking selection guide. Because the successful performance of a marking depends largely on controlling many variables during the installation of the marking, this guide includes pavement marking installation inspection methods for use by IDOT inspectors.FHWA-ICT-13-033, Project R27-077published or submitted for publicationnot peer reviewe

Effect of Short Term Oven Aging on Volumetrics and Selection of N-Design

This report presents findings on the effect of conditioning time on the volumetric properties of Superpave Gyratory Compactor (SGC) prepared asphalt mixtures. Field mixtures were sampled from the producing plants and then recreated in the laboratory following 3 different short-term conditioning procedures to measure the effect on the N-design value of the mixture. The projects selected represent three different N-design levels, have different nominal maximum aggregate size, aggregate sources, and asphalt binder types. Bulk Specific Gravity (Gmb) samples were aged at compaction temperature for 1-hr, 2-hr, and 4-hr. Maximum Specific Gravity (Gmm) samples were also aged at compaction temperature for 0-hr, 2-hr, and 4-hr. The short-term aging times are based off of Illinois Department of Transportation aging procedures, current National Center for Asphalt Technology recommendations, and the original Superpave conditioning specifications. It was observed in this study that increased conditioning time has a greater impact on the volumetric properties of the polymer-modified binder mixes than on neat binder mixes. Also, noticed is that the presence of polymers in the binder appears to have greater effect than the higher temperature used for conditioning polymer-modified HMA.Illinois Department of Transportationpublished or submitted for publicationnot peer reviewe

Effect Of Flat And Elongated Coarse Aggregate On Characteristics Of Gyratory Compacted Samples

This report presents findings on the effect of flat and elongated coarse aggregate particles on the volumetrics of Superpave Gyratory Compactor (SGC) prepared asphalt mixtures. Select aggregate sources were sampled to provide aggregate with varying levels of flat and elongated particles. The particles were hand separated and classified according to the flat and elongated ratio. Mixtures with specific gradations were assembled using the gravel and dolomite aggregates with controlled percentages of 3 to 1 and 5 to 1 particle shapes. Changes in the gradations of the compacted mixtures were noted and related to initial particle shapes and amounts and the aggregate source. No significant impact on mixture volumetrics could be assigned to the presence of flat and elongated particles.Illinois Department of Transportation IHR-R22published or submitted for publicationnot peer reviewe