Hot Mix Asphalt (HMA) paving of airport runways mostly requires multiple paving teams, multiple pavers, and a wide array of other equipment. The runway paving projects are typically renowned for the logistical effort and the tight margins for overruns, often requiring a relatively large part of the contractor’s resources. Due to the nature of airport operations the projects are of a fast-track ...

Over the years, there is a growing trend towards quality-based specifications in highway construction. In many Quality Control/Quality Assurance (QC/QA) specifications, the contractor is primarily responsible for quality control of the process, whereas the highway agency is responsible for testing the acceptance of the product. A cooperative investigation was conducted in Illinois over several ...

EFFECTS OF RUBBER ADDITIVES ON PROPERTIES OF ASPHALTIC MATERIALS by JOHN ALBERT ALEXANDER Submitted to the Department of Civil Engineering on August 17, 1968, in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering. This study investigated the modification of asphalt with various rubbers and the effect of this modification on the values of fracture to...

The fatigue cracks are observed in asphalt surfaces much more than ruts. This paper deals with the influence of carbon nano-tube on the fatigue life of asphalt mixtures. These samples are made up of the slabs cut by the asphalt cutting saw. Fatigue beams contain 0, 0.3, 0.6, 0.9, 1.2, and 1.5 percent of Carbon Nano-tube. The fatigue experiment was conducted using a 4-point semi-sinusoidal loadi...

Asphalt mixture is heterogeneous in nature; therefore, macroscopic parameters alone cannot describe the mechanical behavior of the mixture. In recent years, the arrangement of the aggregate particles in terms of spatial and directional distributions, and contact points are considered as the internal structure of asphalt. The main purpose of this paper is to investigate the microstructural chara...

Superpave is an acronym for Superior Performing Asphalt Pavements. It is the product of the Strategic Highway Research Program. Superpave includes a new mixture design and analysis system based on performance characteristics of the pavement. It is a multi-faceted system with a tiered approach to designing asphalt mixtures based on desired performance. There is a great deal of work underway to r...

In our research project entitled "Chemical irritative and/or genotoxic effect of fumes of bitumen under high processing temperatures on the airways," 73 mastic asphalt workers exposed to fumes of bitumen and 49 construction nonexposed workers were analyzed and compared with respect to polycyclic aromatic hydrocarbons (PAHs) exposure and exposure-related health effects. In order to assess the in...

Airborne emissions from hot asphalt contain mixtures of polycyclic aromatic hydrocarbons (PAHs), including several carcinogens. We investigated urinary biomarkers of three PAHs, namely naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr) in 20 road-paving workers exposed to hot asphalt and in 6 road milling workers who were not using hot asphalt (reference group). Our analysis included basel...

Paving asphalts are often judged and selected based on their rheological behavior at prescribed temperatures or aging response. Asphalts are considered as a colloidal mixture, where clusters of polar, aromatic molecules are dispersed in a less polar solvents. Thus, the extent to which the solvent phase disperses the associating molecules will determine many of the fundamental asphalt properties...

Binder drainage test is widely used to set an upper limit to the design binder content of porous asphalt. However, the presence of high amount of fine particles in the drained binder may affect the accuracy of the test result. This paper presents a study to characterize the composition and particle size distribution of fine particles accumulated in the drained binder. Fine aggregates and filler...