Asphalt road reflectance spectra change as pavement ages. This provides the possibility for remote sensing to be used to monitor a change in asphalt pavement conditions. However, the relatively narrow geometry of roads and the relatively coarse spatial resolution of remotely sensed imagery result in mixtures between pavement and adjacent landcovers (e.g., vegetation, buildings, and soil), incre...

This report provides a summary of the results of the various studies completed in the Partnered Pavement Research Program (PPRC) during the period 2000–2004. In addition, preliminary findings of investigations, initiated but not yet implemented during this period, are included. The results are based on the combined results of analytical developments, laboratory testing of pavement materials, an...

Pavement surface texture and its skid resistance are two key safety parameters of highways, which both are influenced by pavement characteristics. This research is done on a newly constructed asphalt pavement (Qom-Garmsar freeway) in Iran. The goal is investigating the relation between skid resistance and pavement texture in order to asphalt content changes in Hot Mix Asphalt. Mean Texture Dept...

The central purpose of the research is to support the California Department of Transportation (Caltrans) Quieter Pavement Research Program, which has as its goals and objectives the identification of quieter, safer asphalt pavement surfaces. The research conforms with Federal Highway Administration (FHWA) guidance provided to state departments of transportation (DOTs) that conduct tire/pavement...

Reinforcement using an interlayer system has been demonstrated for more than four decades as a multi-purpose solution to improve performance, to extend service life and thus to reduce maintenance costs of road pavements. Among a large number of existing interlayer systems, glass fiber grids have shown effective use in pavement reinforcement with a hot mix asphalt overlay. Recently they have rec...

As one type of pavement distresses, potholes are important clues indicating structural defects of the asphalt road, and accurately detecting these potholes is one of important tasks for determining proper strategies of asphalt-surfaced pavement maintenance and rehabilitation. However, manually detecting and evaluating methods are expensive and timeconsuming. Thus, several efforts have been made...

MATERIALS Pavement Core Samples COAL TAR AND ASPHALT CEMENT SAMPLES METHODS OF ANALYSIS Binder Content PAH Analysis Analysis of Phenols Modified Ames Assay RESULTS Coal Tar and Asphalt Cement Core Sample Analyses COMPARISON OF CORE SAMPLES WITH U.S. AND EUROPEAN ASPHALT AND COAL TARS COMPARISON OF DIN METHOD FOR PHENOLS WITH THE CORE SAMPLES COMPARISON OF MODIFIED AMES TEST RESULTS DISCUSSION C...

Several pavement failures have been observed to be initiated at or near the surface of the hot-mix asphalt layers and some of them propagate downward through the surface layer (top-down cracking). These modes of failure are affected by heavy vehicular loading configuration, pavement structure and their interaction at the tire-pavement contact. This paper documents an experimental investigation ...

PROBLEM STATEMENT When designing and evaluating asphalt pavements, engineers must have an understanding of how the pavement materials will react to the stresses and strains of vehicle loads at varying temperatures. When a load is applied to asphalt concrete at a certain temperature, to what degree will the pavement "bounce back" to its original height? Pavement designers predict this spring-lik...

Recently developed Mechanistic-Empirical Pavement Design Guide (MEPDG) determines the probable total rutting by summing up the deformations of all layers of the trial pavement. If all distresses outcomes including rutting are within the specification the trial section is designed for construction. Therefore, vertical deformation (or strain) needs to be measured to validate the MEPDG for local c...